Test corrections 2
9. The solubility of a solute must indicate
A. the temperature of the solution B. the quantity of solute C. the quantity of solvent Read more at http://www.cracksat.net/sat2/chemistry/question-438-answer-and-explanation.html#t9chFY8Bc7hyOyBo.99
The organic acid that can be made from ethanol is A. acetic acid B. formic acid C. C3H7OH D. found in bees and ants E. butanoic acid
Correct Answer: A Explanation: (A) Ethanol can be oxidized into the organic acid enthanoic acid, which has the common name of acetic acid. Read more at http://www.cracksat.net/sat2/chemistry/question-517-answer-and-explanation.html#oyYaofHcs6OEYW6J.99
6. In the electrolysis of copper chloride, the substance liberated at the anode is A. copper B. chlorine C. hydrogen D. copper chloride E.
Correct Answer: B Explanation: (B) Because the anode is positively charged, it attracts the negatively charged Cl- ions that are released from copper chloride. When it is oxidized by losing its electon, the chlorine atom then forms a Cl2 molecule with another atom of chlorine to be released as chlorine gas. The anode reaction would be: Read more at http://www.cracksat.net/sat2/chemistry/question-485-answer-and-explanation.html#EyPdp7yx8Eehi8Yh.99
14. H2S and H2O have a significant difference in their boiling points BECAUSE hydrogen sulfide has a higher degree of hydrogen bonding than water. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: B Explanation: (B) The assertion that the boiling points of H2S and H2O are significantly different is true, but the reason is false. Water has the higher degree of hydrogen bonding. Read more at http://www.cracksat.net/sat2/chemistry/question-628-answer-and-explanation.html#KTZBifLAGDQLluAA.99
In this setup, a clean strip of magnesium with a mass of 0.040 g was introduced into the bottom of the tube, which contained a dilute solution of HCl, and allowed to react completely. The hydrogen gas formed was collected and the following data recorded: Air pressure in the room = 730 mm Hg Temperature of the water solution = 302 K Vapor pressure of water at 302 K = 30.0 mm Hg The gas collected did not fill the eudiometer. The height of the meniscus above the level of the water was 40.8 mm. What is the theoretical yield (in mL) at STP of hydrogen gas produced when the 0.040 g of Mg reacted completely? A. 10 mL B. 25 mL C. 37 mL D. 46 mL E. 51 mL
Correct Answer: C Explanation: (C) The theoretical yield at STP can be found from the chemical equation of the reaction: Read more at http://www.cracksat.net/sat2/chemistry/question-537-answer-and-explanation.html#gYUdfsMaKMUtQR8h.99
What mass of aluminum will be completely oxidized by 2 moles of oxygen at STP? A. 18 g B. 37.8 g C. 50.4 g D. 72.0 g E. 100.8 g
Correct Answer: D Read more at http://www.cracksat.net/sat2/chemistry/question-765-answer-and-explanation.html#uEmBy7lJtlSpWfde.99
5. 5.00 liters of gas at STP have a mass of 12.5 grams. What is the molar mass of the gas? A. 12.5 g/mol B. 25.0 g/mol C. 47.5 g/mol D. 56.0 g/mol E. 125 g/mol
Correct Answer: D Explanation: (D) One mole of a gas at STP occupies 22.4 L. Read more at http://www.cracksat.net/sat2/chemistry/question-849-answer-and-explanation.html#lMzfqw70SwEdDJxB.99
19. The reason why a blue crystal of CuSO4 · 5H2O turns white when heated A. Brownian movement B. Litmus paper reaction C. Phenolphthalein reaction D. Dehydration E. Deliquescent
Correct Answer: D Explanation: (D) When hydrated copper sulfate is heated, the crystal crumples as the water is forced out of the structure, and a white powder is the result. Hydrates are formed due to a crystallization process
7. The Hreaction of a particular reaction can be arrived at by the summation of the Hreaction values of two or more reactions that, added together, give the Hreaction of the particular reaction BECAUSE Hess's Law conforms to the First Law of Thermodynamics, which states that the total energy of the universe is a constant. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Read more at http://www.cracksat.net/sat2/chemistry/question-789-answer-and-explanation.html#ttOvWmjakEEb0Qji.99
23. The adsorbtion of water to the surface of a crystal A. Brownian movement B. Litmus paper reaction C. Phenolphthalein reaction D. Dehydration E. Deliquescent
Correct Answer: E Explanation: (E) A substance that is deliquescent, such as a crystal, draws water to its surface. At times it can draw enough water to form a water solution. Read more at http://www.cracksat.net/sat2/chemistry/question-821-answer-and-explanation.html#8ZWR1MCI2w4Cp2jd.99
In the equilibrium reaction N2(g) + 3H2(g) ←→ 2NH3(g) + heat when the pressure in the reaction chamber is increased, the reaction shifts to the right BECAUSE the increase in pressure causes the reaction to shift to the right to decrease the pressure since 4 volumes on the left become 2 volumes on the right. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) An equilibrium system must have a gaseous reactant or product for pressure to affect the equilibrium. Then increased pressure will cause the reaction to go in the direction that reduces the concentration of gaseous substances. Since four volumes of gases on the left became two volumes on the right, the reaction shifts to the right. Read more at http://www.cracksat.net/sat2/chemistry/question-874-answer-and-explanation.html#Bv8ZmQPDIT6blT2O.99
The ionic bond is the strongest bond BECAUSE ionic bonds have electrostatic attraction due to the loss and gain of electron(s). A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) Both statements are true, and the reason explains why ionic bonding is the strongest. Read more at http://www.cracksat.net/sat2/chemistry/question-873-answer-and-explanation.html#s8tOVgcLBfACf6Ml.99
When excited electrons cascade to lower energy levels in an atom, A. visible light is always emitted B. the potential energy of the atom increases C. the electrons always fall back to the first energy level D. the electrons fall indiscriminately to all levels E. the electrons fall back to a lower unfilled energy level
Correct Answer: E Explanation: (E) Cascading excited electrons can fall only to lower energy levels that are unfilled. Read more at http://www.cracksat.net/sat2/chemistry/question-830-answer-and-explanation.html#aLFOximdHsQ5pmas.99
5. Crystals of sodium chloride go into solution in water as ions BECAUSE the sodium ion has a 1+ charge and the chloride ion has a 1- charge and they are hydrated by the water molecules. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) Sodium chloride is an ionic crystal, not a molecule, and its ions are hydrated by the polar water molecules. Read more at http://www.cracksat.net/sat2/chemistry/question-787-answer-and-explanation.html#tvFvQoyHRMMOlDTh.99
What is the value of Kb and Kf for water
Kb = 0.51 C Kf = 1.86 C
Metals with the higher reactivity ... Metals with lower reactivity
Will under go oxidation and be oxidized Will under go reduction and be reduced
common ion effect
the lowering of the solubility of an ionic compound as a result of the addition of a common ion
1. Which of the following when dissolved in water and placed in the conductivity apparatus would cause the light to glow? A. table salt B. ethyl alcohol C. sugar D. glycerine 2. In question 1, the reason that a current could flow is that A. ions combine to form molecules B. molecules migrate to the charge plates C. ions migrate to the charge plates D. sparks cross the gap E.
1. Correct Answer: A Explanation: (A) Table salt is the only substance listed that has ions when dissolved in its water solution and will show a current is moving through the system by lighting the conductivity apparatus. 2. Correct Answer: C Explanation: (C) The current is carried through the solution by ions migrating to the charged plates that act as the anode and the cathode. Read more at http://www.cracksat.net/sat2/chemistry/question-481-answer-and-explanation.html#sWSuTCcpPiPyGFIG.99
A student filled a steam-jacketed eudiometer with 32. milliliters of oxygen and 4.0 milliliters of hydrogen over mercury. How much of which gas would be left uncombined after the mixture was sparked? A. None of either B. 3.0 mL H2 C. 24 mL O2 D. 28 mL O2 E. 30. mL O2 What would be the total volume, in milliliters, of gases in question 60 after sparking? A. 16 B. 24 C. 34 D. 36 E. 40
1. Correct Answer: E Explanation: (E) H2 to O2 ratio by volume is 2 : 1 in the formation of water. Therefore, 4.0 mL H2 will react with 2.0 mL of O2 to make 4.0 mL of steam. 2H2(g) + O2(g) → 2H2O(g) This leaves 30. mL of O2 uncombined. Read more at http://www.cracksat.net/sat2/chemistry/question-858-answer-and-explanation.html#ALiy06hO5Ee6TPO7.99 2. Correct Answer: C Explanation: (C) There will be 30. mL of O2 + 4.0 mL of steam = 34 mL total Read more at http://www.cracksat.net/sat2/chemistry/question-859-answer-and-explanation.html#0d3hwIJGw7gfSPy6.99
1. To plate silver on the spoon, the position to which the wire from the spoon must be connected 2. The position of the anode 3. The position from which silver that is plated out emerges
1. Correct Answer: B Explanation: (B) The spoon must be made the cathode to attract the Ag+ ions. 2. Correct Answer: D Explanation: (D) The silver plate is the anode. 3. Correct Answer: E Explanation: (E) The solution of Ag+ provides the silver for plating.
2. The ratio in water of hydrogen to oxygen by mass is A. 1:09 B. 2:01 C. 1:02 D. 1:08 E. 3. Decomposing water by an electric current will give a ratio of hydrogen to oxygen by volume equal to A. 1:09 B. 2:01 C. 1:02 D. 1:08 E.
2. Correct Answer: D Explanation: (D) In the molar mass of water, there are 2 hydrogen = 2 g and 1 oxygen = 16 g. So the H/O ratio by mass is 2 g/16 g or 1/8. 3. Correct Answer: B Explanation: (B) In the balanced reaction, 2H2O → 2H2(g) + O2(g), 2 volumes of hydrogen are released to 1 volume of oxygen, so the ratio is 2:1.
A foam is an example of
A. a gas dispersed in a liquid
How do you calculate the chang in FP or BP
BP = BPnormal + ∆Tb FP = FPnormal - ∆Tf
Basic vs acid anhydrides
Basic - metal oxides with water acid - nonmetal oxides with water
What is the formula for boiling point elevation and freezing point depression
Boiling Point elevation ∆Tb = i Kb m Freezing Point Depression ∆Tf = Tf = i Kf m i = Van Hoff = mol particle/mol solute Kb or Kf = constant (different for each solvent) m = molality
What happens to the boiling point of water as it moves to a higher altitude
Boling point decreases due to a lower pressure at high altitiudes The boling point decreases 0.5 C every 500 ft. above sea level
What is the molar mass of a nonionizing solid if 10. grams of this solid, dissolved in 200. grams of water, formed a solution that froze at -3.72°C? A. 25. g/mol B. 50. g/mol C. 100. g/mol D. 150. g/mol E. 1,000. g/mol
Correct Answer: A Explanation: (A) 10. g/200. g of water = 50. g/1,000. g of water (5 times as much) The freezing point depression, 3.72°, is divided by 1.86°, which is the depression caused by 1 mol in 1,000. g of water, to find how many moles are dissolved. 3.72° ÷ 1.86° = 2 mol If 50. g caused this depression and is equal to 2 mol, then 1 mol would be image: http://www.cracksat.net/sat2/chemistry/images2/00684.jpeg of 50. g, or 25 g. So, the molar mass of the solid is 25 g/mol. Read more at http://www.cracksat.net/sat2/chemistry/question-867-answer-and-explanation.html#dBkhR3Mo3xJvjhIW.99
A gas at STP that contains 6.02 × 10^23 atoms and forms diatomic molecules will occupy A. 11.2 L B. 22.4 L C. 33.6 L D. 67.2 L E. 1.06 qt
Correct Answer: A Explanation: (A) If the gas is diatomic, then 6.02 × 1023 atoms will form 6.02 × 1023/2 molecules. At STP, 6.02 × 1023 molecules occupy 22.4 L, so half that number will occupy 11.2 L. Read more at http://www.cracksat.net/sat2/chemistry/question-829-answer-and-explanation.html#o1gDiS9XWJWoErTV.99
8. In the Haber process for making ammonia, an increase in pressure favors A. the forward reaction B. the reverse reaction C. neither reaction D. E.
Correct Answer: A Explanation: (A) In the reaction for the formation of ammonia, N2 + 3H2 ←→ 2NH3 + heat (at equilibrium). An increase in pressure will cause the forward reaction to be favored, because the equation shows that four molecules of reactants are forming two molecules of products. This effect tends to reduce this increase in pressure by the formation of more ammonia. Read more at http://www.cracksat.net/sat2/chemistry/question-462-answer-and-explanation.html#WCpTEPxo6xWv3WPY.99
17. What would be the predicted freezing point of a solution that has 684 grams of sucrose (1 mol = 342 g) dissolved in 2,000 grams of water? A. -1.86°C or 271.14 K B. -0.93°C or 272.07 K C. -1.39°C or 271.61 K D. -2.48°C or 270.52 K E. -3.72°C or 269.28 K
Correct Answer: A Explanation: (A) One mole of dissolved substance (which does not ionize) causes a 1.86°C drop in the freezing point of a 1 molal solution. Since 2,000 g of water were used, the solution has 2 mol in 2,000 g of water. The freezing point is depressed 1 × -1.86° = -1.86°C or 271.14 K. Read more at http://www.cracksat.net/sat2/chemistry/question-753-answer-and-explanation.html#ikGH30xx1BFUcZqv.99
15. Which of the following properties can be attributed to water? I. It has a permanent dipole moment attributed to its molecular structure. II. It is a very good conductor of electricity. III. It has its polar covalent bonds with hydrogen on opposite sides of the oxygen atom, so that the molecule is linear. A. I only B. III only C. I and II only D. II and III only E. I, II, and III
Correct Answer: A Explanation: (A) Only I is correct. Read more at http://www.cracksat.net/sat2/chemistry/question-836-answer-and-explanation.html#ozEC7hCtC2xheDLe.99
Which of the following does NOT react with a dilute solution of sulfuric acid? A. NaNO3 B. Na2S C. Na3PO4 D. Na2CO3 E. NaOH
Correct Answer: A Explanation: (A) Only NaNO3 will not react because it requires heat to react. Read more at http://www.cracksat.net/sat2/chemistry/question-863-answer-and-explanation.html#8LlpzykrZfSMut4L.99
13. When sulfur dioxide is bubbled through water, the solution will contain A. sulfurous acid B. sulfuric acid C. hyposulfuric acid D. persulfuric acid E. anhydrous sulfuric acid
Correct Answer: A Explanation: (A) SO2 is the acid anhydride of H2SO3 or sulfurous acid. H2O + SO2 → H2SO3. Read more at http://www.cracksat.net/sat2/chemistry/question-749-answer-and-explanation.html#OwoUz0xlMZI205bL.99
The reaction of CaCO3 and HCl goes to completion BECAUSE reactions that form a precipitate tend to go to completion. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: A Explanation: (A) The reaction does go to completion, but a gaseous product is formed, not a precipitate, so II does not explain I. Read more at http://www.cracksat.net/sat2/chemistry/question-882-answer-and-explanation.html#2CTaSR0kscEzuYJg.99
There are 3 moles of atoms in 18 grams of water BECAUSE there are 6 × 1023 atoms in 1 mole. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: A Explanation: (A) There are 3 moles of atoms in 18 g of water because 18 g is 1 mol of water molecules and each molecule has three atoms. The reason does not explain the assertion but is also true. Read more at http://www.cracksat.net/sat2/chemistry/question-879-answer-and-explanation.html#dfG3KdaLYjz2HO7J.99
An increase in concentration A. is related to the number of collisions directly B. is related to the number of collisions inversely C. has no effect on the number of collisions D. E.
Correct Answer: A Explanation: (A) When the concentration of reactants is increased, the number of collisions between reactants is directly affected because there are more reactant units (ions, atoms, or molecules) available. Read more at http://www.cracksat.net/sat2/chemistry/question-452-answer-and-explanation.html#UWT1POMw6KywJtg0.99
13. A pi bond is formed between the lobes of adjacent p orbitals in the same plane of two atoms that contain only one electron each BECAUSE each of the two lobes of a single p orbital can hold two electrons of opposite spin. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: B B) A pi bond is formed between p lobes of adjacent atoms and in the same plane: However, each p orbital consisting of two lobes can hold a total of two electrons, so the reason is false. Read more at http://www.cracksat.net/sat2/chemistry/question-627-answer-and-explanation.html#0RIVjDgCyAJijd7l.99
23. This question pertains to the reaction represented by the following equation: 2NO(g)+ O2 (g) → 2NO2 (g)+ 150 kJ Suppose that 0.8 mole of NO is converted to NO2 in the above reaction. What amount of heat will be evolved? A. 30 kJ B. 60 kJ C. 80 kJ D. 130 kJ E. 150 kJ
Correct Answer: B Read more at http://www.cracksat.net/sat2/chemistry/question-590-answer-and-explanation.html#s4gKDopc386pXjly.99
10. If Ca(OH)2 is dissolved in a solution of NaOH, its solubility, compared with that in pure water, is A. increased B. decreased C. unaffected D. E.
Correct Answer: B Explanation: (B) Because there already is a concentration of (OH)- ions from the NaOH in solution, this common ion effect will decrease the solubility of the Ca(OH)2. Read more at http://www.cracksat.net/sat2/chemistry/question-464-answer-and-explanation.html#XmV9BS1ZWTRB16ys.99
11. Electrode potentials are: Zn0 → Zn2+ + 2e- E0 = + 0.76 V Au0 → Au3+ + 3e- E0 = -1.42 V If a gold foil were placed in a solution containing zinc ions, the reaction potential would be calculated to be A. -1.34 V (no reaction) B. -2.18 V (no reaction) C. -0.66 V (no reaction) D. +2.18 V (reaction) E. +1.34 V (reaction)
Correct Answer: B Explanation: (B) Because zinc is higher than gold in the standard reduction potentials listing, it will remain in the ionic form, whereas gold will favor the nonionized form. The two half-reactions that would have to occur with the electrode potentials for each are: This negative cell potential indicates that these reactions would not occur. * Note: The standard potentials (E0) are not multiplied by the coefficients in calculating the E0 for the reaction. Previous Next Read more at http://www.cracksat.net/sat2/chemistry/question-490-answer-and-explanation.html#sp5BDyE7uKktiFxW.99
A reducing agent used in the blast furnace is A. CaCO3 B. CO C. O2 D. SiO2 E.
Correct Answer: B Explanation: (B) CO, carbon monoxide, is used in the blast furnace as a reducing agent to react with oxide impurities. Read more at http://www.cracksat.net/sat2/chemistry/question-505-answer-and-explanation.html#PHyYEZsr63cDSMyj.99
In the laboratory, a sample of hydrated salt was heated at 110°C for 30 minutes until all the water was driven off. The data were as follows: Mass of the hydrate before heating = 250 grams Mass of the hydrate after heating = 160 grams From these data, what was the percent of water by mass in the original sample? A. 26.5 B. 36 C. 47 D. 56 E. 90
Correct Answer: B Explanation: (B) Hydrate mass before heating = 250. g - Hydrate mass after heating = 160. g Water loss = 90.0 g Read more at http://www.cracksat.net/sat2/chemistry/question-596-answer-and-explanation.html#mYaP3oY1HuUYipHT.99
19. How many grams of NaOH are needed to make 100 grams of a 5% solution? A. 2 B. 5 C. 20 D. 40 E. 95
Correct Answer: B Explanation: (B) If the solution is to be 5% sodium hydroxide, then 5% of 100 g is 5 g. Percent is always by mass unless otherwise specified. Read more at http://www.cracksat.net/sat2/chemistry/question-755-answer-and-explanation.html#EI43ZKLsxD6RGTES.99
7. In the laboratory, 20.0 milliliters of an aqueous solution of calcium hydroxide, Ca(OH)2, was used in a titration. A drop of phenolphthalein was added to it to indicate the end point. The solution turned colorless after 20.0 milliliters of a standard solution of 0.050 M HCl solution was added. What was the molarity of the Ca(OH)2? A. 0.010 M B. 0.025 M C. 0.50 M D. 0.75 M E. 1.0 M
Correct Answer: B Explanation: (B) In the titration, the reaction is: 2HCl + Ca(OH)2 → CaCl2 + 2H2O The acid to base ratio is 2 : 1, or (moles acid used) = 2(moles base used), so MaVa = 2MbVb, where M is the molarity and V is the volume expressed in liters, then Read more at http://www.cracksat.net/sat2/chemistry/question-598-answer-and-explanation.html#8BSJGbVAd1tCOV8W.99
Mass spectroscopy uses the concept that A. charged particles are evenly deflected in a magnetic field B. charged particles are deflected in a magnetic field inversely to the mass of the particles C. particles of heavier mass are deflected in a magnetic field to a greater degree than lighter particles D. particles are evenly deflected in a magnetic field E. None of above
Correct Answer: B Explanation: (B) Mass spectroscopy uses a magnetic field to separate isotopes by bending their path. The lighter ones are bent farther than the heavier ones. Read more at http://www.cracksat.net/sat2/chemistry/question-831-answer-and-explanation.html#kQswwETGWbZChdDR.99
7. In general, when metal oxides react with water, they form solutions that are A. acidic B. basic C. neutral D. unstable E. colored
Correct Answer: B Explanation: (B) Metal oxides are generally basic anhydrides. Previous Next Read more at http://www.cracksat.net/sat2/chemistry/question-766-answer-and-explanation.html#P4P2RLO40xR48cFy.99
19. When 1 mole of NaCl is dissolved in 1,000 grams of water, the boiling point of the water is changed to A. 100.51°C B. 101.02°C C. 101.53°C D. 101.86°C E. 103.62°C
Correct Answer: B Explanation: (B) Since the boiling point is increased by 0.51°C for each mole of particles, 1 mol of NaCl → Na+ + Cl- gives 2 mol of particles. Therefore the boiling point will be 1.02° higher or 101.02°C. Read more at http://www.cracksat.net/sat2/chemistry/question-840-answer-and-explanation.html#ZelBtkyebokLizmb.99
1. The structure of SO3 is shown by using more than one structural formula BECAUSE SO3 is very unstable and resonates between these possible structures. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: B Explanation: (B) Sulfur trioxide is shown by three structural formulas because each bond is "hybrid" of a single and double bond. Resonance in chemistry does not mean that the bonds resonate between the structures shown in the structural drawing. Read more at http://www.cracksat.net/sat2/chemistry/question-783-answer-and-explanation.html#QefJf7pXCS3Lmuix.99
The lab setup shown above was used for the gravimetric analysis of the empirical formula of MgO. In synthesizing MgO from a Mg strip in the crucible, which of the following is NOT true? A. The initial strip of Mg should be cleaned. B. The lid of the crucible should fit tightly to exclude oxygen. C. The heating of the covered crucible should continue until the Mg is fully reacted. D. The crucible, lid, and the contents should be cooled to room temperature before measuring their mass. E. When the Mg appears to be fully reacted, the crucible lid should be partially removed and heating continued.
Correct Answer: B Explanation: (B) The Mg needs oxygen to form MgO; so the lid cannot be tightly sealed. Oxygen is needed for the Mg to oxidize to MgO. All other choices are true. Read more at http://www.cracksat.net/sat2/chemistry/question-760-answer-and-explanation.html#0Jp17sL4LDyK0fIU.990Jp17sL4LDyK0fIU.99
18. What is the approximate pH of a 0.005 M solution of H2SO4? A. 1 B. 2 C. 5 D. 9 E. 13
Correct Answer: B Explanation: (B) The pH is -log[H+]. A 0.005 molar solution of H2SO4 ionizes in a dilute solution to release two H+ ions per molecule of H2SO4. Therefore the molar concentration of H+ ion is 2 × 0.005 mol/L or 0.010 mol/L. Substituting this in the formula, you have: pH = -log[0.01]= -log[1 × 10-2] The log of a number is the exponent to which the base 10 is raised to express that number in exponential form: - log[1 × 10-2]= -[-2]= 2 Read more at http://www.cracksat.net/sat2/chemistry/question-754-answer-and-explanation.html#ZxKyScOvq9oaCuqY.99
23. How many moles of electrons are required to reduce 2.93 grams of nickel ions from melted NiCl2? (Molar mass of Ni = 58.7 g/mol) A. 0.050 B. 0.10 C. 1.0 D. 1.5 E. 2.0
Correct Answer: B Explanation: (B) The reaction is Ni2+ + 2e- → Ni (s) Since 2 mol of electrons are required to form 1 mol of nickel, and Read more at http://www.cracksat.net/sat2/chemistry/question-614-answer-and-explanation.html#0Fc8wz8xDpyrSLGG.99
21. If you titrate 1.0M H2SO4 solution against 50. milliliters of 1.0M NaOH solution, what volume of H2SO4, in milliliters, will be needed for neutralization? A. 10. B. 25. C. 40. D. 50. E. 100
Correct Answer: B Explanation: (B) The reaction is: 1 mol acid = 0.5 (mol) of base Since molarity × volume (L) = moles, then MaVa = MbVb (1.0 M)(x L) = (1 M)(0.05 L) x L =(0.05 L) x L = 0.025 L or 25.mL Read more at http://www.cracksat.net/sat2/chemistry/question-757-answer-and-explanation.html#6MdEBZPIMkMP7oKV.99
4. Sulfur dioxide is the anhydride of A. hydrosulfuric acid B. sulfurous acid C. sulfuric acid D. hyposulfurous acid E.
Correct Answer: B Explanation: (B) The reaction of SO2 with water forms sulfurous acid. The equation is: SO2 + H2O → H2SO3. Read more at http://www.cracksat.net/sat2/chemistry/question-498-answer-and-explanation.html#pXoUl5Ij0522BbXQ.99
8. In a reaction that has both a forward and a reverse reaction, the forward reaction rate is the highest at the beginning and begins to decrease from that point until equilibrium is reached BECAUSE the reverse reaction does not begin until equilibrium is reached. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: B Explanation: (B) The statement is true, but not the reason. In an equilibrium reaction, concentrations can be shown to progress like this: Read more at http://www.cracksat.net/sat2/chemistry/question-790-answer-and-explanation.html#KMdH2WJO6H4q2D8K.99
1. When another crystal was added to a water solution of the same substance, the crystal seemed to remain unchanged. Its particles were A. going into an unsaturated solution B. exchanging places with others in the solution C. causing the solution to become supersaturated D. not going into solution in this static condition E.
Correct Answer: B Explanation: (B) This situation describes a saturated solution where an equilibrium exists between the undissolved solute and the solute particles in solution. Read more at http://www.cracksat.net/sat2/chemistry/question-440-answer-and-explanation.html#0V8YifQcT1JBKWGS.99
15. What mass of CaCO3 is needed to produce 11.2 liters of CO2 at STP when the calcium carbonate is reacted with an excess amount of hydrochloric acid? (Molar masses: CaCO3 = 100. g/mol, HCl = 36.5 g/mol, CO2 = 44.0 g/mol) A. 25.0 g B. 44.0 g C. 50.0 g D. 100. g E. None of the above
Correct Answer: C Read more at http://www.cracksat.net/sat2/chemistry/question-606-answer-and-explanation.html#CiO7gvSU6rbHzBic.99
23. What is the percent dissociation of acetic acid in a 0.1 M solution if the [H3O+] is 1 × 10-3 mole/liter? A. 0.01% B. 0.1% C. 1.0% D. 1.5% E. 2.0%
Correct Answer: C Explanation: Read more at http://www.cracksat.net/sat2/chemistry/question-782-answer-and-explanation.html#5iXTQeyTVdSrE770.99
18. To the equilibrium reaction shown below: AgCl(s) image: http://www.cracksat.net/sat2/chemistry/images2/00035.jpeg Ag+ + Cl- a beaker of concentrated HCl (12 M) is slowly added. Which is the best description of what will occur? A. More salt will go into solution, and the Ksp will remain the same. B. More salt will go into solution, and the Ksp will increase. C. Salt will come out of the solution, and the Ksp will remain the same. D. Salt will come out of the solution, and the Ksp will decrease. E. No change in concentration will occur, and the Ksp will increase.
Correct Answer: C Explanation: (C) Because the HCl solution will add to the chloride ion concentration, according to Le Châtelier's Principle the equilibrium will shift in the direction to reduce this disturbance, so the Ksp will remain the same but salt will come out of solution. This process: AgCl image: http://www.cracksat.net/sat2/chemistry/images2/00030.jpeg Ag+ + Cl- will continue until the Ksp is reestablished. This phenomenon is called the "common ion effect." Read more at http://www.cracksat.net/sat2/chemistry/question-609-answer-and-explanation.html#fpmtHoeZgtzhclRW.99
Recorded data: Weight of U-tube................................ 20.36 g Weight of U-tube and calcium chloride before................................................... 39.32 g Weight of U-tube and calcium chloride after................................................... 57.32 g Weight of boat and contents (copper oxide) before................................................... 30.23 g Weight of boat and contents after................................................... 14.23 g Weight of boat...................................................5.00 g What conclusion can be derived from the data collected? A. Oxygen was lost from the CaCl2. B. Oxygen was generated in the U-tube. C. Water was formed from the reaction. D. Hydrogen was absorbed by the CaCl2. E. CuO was formed in the decomposition.
Correct Answer: C Explanation: (C) Calcium chloride is deliquescent, and its weight gain of water indicates that water was formed from the reaction. Read more at http://www.cracksat.net/sat2/chemistry/question-762-answer-and-explanation.html#VWy02uj2Sh3iOFfK.99
Hydrogen gas is collected in a eudiometer tube over water as shown above. The water level inside the tube is 40.8 millimeters higher than that outside. The barometric pressure is 730. millimeters Hg. The water vapor pressure at the room temperature of 29°C is found in a handbook to be 30.0 millimeters Hg. What is the pressure of the dry hydrogen? A. 659.2 mm Hg B. 689.2 mm Hg C. 697.0 mm Hg D. 740.8 mm Hg E. 800.8 mm Hg
Correct Answer: C Explanation: (C) Change the water height to the equivalent Hg height: = 3 mm Hg Adjust for the difference in height to get the gas pressure. Pressure on the gas is 730. mm Hg - 3 mm Hg = 727 mm Hg. Vapor pressure of H2O at 29°C accounts for 30 mm Hg pressure. Therefore 727 mm Hg - 30 mm Hg = 697 mm Hg Read more at http://www.cracksat.net/sat2/chemistry/question-613-answer-and-explanation.html#ICc3jFhppXkWdSt2.99
Equilibrium is a static condition BECAUSE at equilibrium, the forward reaction rate equals the reverse reaction rate. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: C Explanation: (C) Equilibrium is a dynamic condition because of the reason stated. The assertion is false; the reason, true. Read more at http://www.cracksat.net/sat2/chemistry/question-872-answer-and-explanation.html#4qwVLTbVCzPIEhGp.99
8. The anions in an electrolytic cell migrate to the cathode BECAUSE positively charged ions are attracted to the negatively charged cathode in an electrolytic cell A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: C Explanation: (C) In an electrolyte reaction, anions migrate to the anode. It is true that positively charged ions (cations) are attracted to the negatively charged cathode. Read more at http://www.cracksat.net/sat2/chemistry/question-622-answer-and-explanation.html#zD7cvJdfClYie2Lw.99
A large number of alpha particles were deflected in the Rutherford experiment BECAUSE alpha particles that came close to the nucleus of the gold atoms were deflected. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: C Explanation: (C) In the Rutherford experiment relatively few alpha particles were deflected, indicating a great deal of empty space in the atom. The reason is a true statement. Read more at http://www.cracksat.net/sat2/chemistry/question-883-answer-and-explanation.html#mYKR7oFZQ2yeSQrj.99
12. The polarity of water is useful in explaining which of the following? I. The solution process II. The ionization process III. The high conductivity of distilled water A. I only B. II only C. I and II only D. II and III only E. I, II, and III
Correct Answer: C Explanation: (C) Only I and II are true. Distilled water does not significantly conduct an electric current. The polarity of the water molecule is helpful in ionization and in causing substances to go into solution. Read more at http://www.cracksat.net/sat2/chemistry/question-748-answer-and-explanation.html#QQJria1pjQw70mgj.99
When a crystal is added to a supersaturated solution of itself, the crystal does not appear to change BECAUSE the supersaturated solution is holding more solute than its normal solubility. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: C Explanation: (C) The assertion is false and the reason is true. A supersaturated solution is holding more than its normal solubility, and the addition of a crystal causes crystallization to occur. That is why you test a supersaturated solution with a crystal Read more at http://www.cracksat.net/sat2/chemistry/question-871-answer-and-explanation.html#oa41zraC4PvQ5x1t.99
10. Electrolysis of a dilute solution of sodium chloride results in the cathode product A. (A) sodium B. (B) chlorine C. (C) hydrogen D. (D) oxygen E.
Correct Answer: C Explanation: (C) The electrolysis of a dilute water solution of sodium chloride contains chloride ions, which are attracted to the anode and are set free as chlorine molecules. The cathode reaction is somewhat more complicated. Although the sodium ions are attracted to the cathode, they are not set free as atoms. Because water can ionize to some extent and the standard electrode chart shows that the hydrogen ion is reduced more easily than the sodium ion, it is hydrogen, not sodium, that is set free at the cathode. The reactions are: Read more at http://www.cracksat.net/sat2/chemistry/question-489-answer-and-explanation.html#rMIZL8RWl99FJzhL.99
An ester can be prepared by the reaction of A. two alcohols B. an alcohol and an aldehyde C. an alcohol and an organic acid D. an organic acid and an aldehyde E. an acid and a ketone
Correct Answer: C Explanation: (C) The formation of an ester is from the reaction of an organic acid and an alcohol. The general equation is: Read more at http://www.cracksat.net/sat2/chemistry/question-518-answer-and-explanation.html#Ajvp5fZi5ZOWrlZE.99
7. A nitrogen compound that has a color is A. nitric oxide B. nitrous oxide C. nitrogen dioxide D. ammonia E.
Correct Answer: C Explanation: (C) The only nitrogen compound in the list that has a reddish brown color is nitrogen dioxide. Read more at http://www.cracksat.net/sat2/chemistry/question-501-answer-and-explanation.html#DiOk3epPGzucIFQI.99
9. If 1 mole of each of the following substances was dissolved in 1,000 grams of water, which solution would have the highest boiling point? A. NaCl B. KCl C. CaCl2 D. C6H10O5 E. C12H22O11
Correct Answer: C Explanation: (C) The rise in the boiling point depends on the number of particles in solution. One mole of CaCl2 gives 3 mol of ions, more than any other substance listed: CaCl2 → Ca2++2Cl-. The number of moles of ions given by the other substances are as follows: (A) = 2, (B) = 2, (D) = 1, (E) = 1. Read more at http://www.cracksat.net/sat2/chemistry/question-576-answer-and-explanation.html#qWWBpReCQ9aRW6Ox.99
Recorded data: Weight of U-tube................................ 20.36 g Weight of U-tube and calcium chloride before................................................... 39.32 g Weight of U-tube and calcium chloride after................................................... 57.32 g Weight of boat and contents (copper oxide) before................................................... 30.23 g Weight of boat and contents after................................................... 14.23 g Weight of boat...................................................5.00 g What is the reason for the first CaCl2 drying tube? A. Generate water B. Absorb hydrogen C. Absorb water that evaporates from the flask D. Decompose the water from the flask E. Act as a catalyst for the combination of hydrogen and oxygen
Correct Answer: C Explanation: (C) To ensure that all the water vapor collected in the U-tube comes from the reaction, the first drying tube is placed in the path of the hydrogen to absorb any evaporated water. Read more at http://www.cracksat.net/sat2/chemistry/question-761-answer-and-explanation.html#KVKhgRsj8MaTDQUu.99
Recorded data: Weight of U-tube................................ 20.36 g Weight of U-tube and calcium chloride before................................................... 39.32 g Weight of U-tube and calcium chloride after................................................... 57.32 g Weight of boat and contents (copper oxide) before................................................... 30.23 g Weight of boat and contents after................................................... 14.23 g Weight of boat...................................................5.00 g What is the ratio of the mass of water formed to the mass of hydrogen used in the formation of water? A. 1 : 8 B. 1 : 9 C. 8 : 1 D. 9 : 1 E. 8 : 9
Correct Answer: D Read more at http://www.cracksat.net/sat2/chemistry/question-763-answer-and-explanation.html#RRAUgtDqd0y7cUoe.99
Coke is produced from bituminous coal by A. cracking B. synthesis C. substitution D. destructive distillation E.
Correct Answer: D Explanation: (D) Bituminous coal has too much gaseous impurities to burn at a high temperature needed to refine iron ore. It is heated in coke ovens to form the hotter and cleaner burning coke. Read more at http://www.cracksat.net/sat2/chemistry/question-510-answer-and-explanation.html#rEjbd21ZA0sGZy8o.99
In this setup, a clean strip of magnesium with a mass of 0.040 g was introduced into the bottom of the tube, which contained a dilute solution of HCl, and allowed to react completely. The hydrogen gas formed was collected and the following data recorded: Air pressure in the room = 730 mm Hg Temperature of the water solution = 302 K Vapor pressure of water at 302 K = 30.0 mm Hg The gas collected did not fill the eudiometer. The height of the meniscus above the level of the water was 40.8 mm. What is the pressure of the collected gas once you have also corrected for the vapor pressure of the water? A. 730 mm Hg B. 727 mm Hg C. 30.0 mm Hg D. 697 mm Hg E. 760 mm Hg
Correct Answer: D Explanation: (D) Correcting the previous pressure by subtracting the given amount for the vapor pressure of water at 302 K gives you 727 mm Hg - 30 mm Hg vapor pressure = 697 mm Hg as the final pressure. Read more at http://www.cracksat.net/sat2/chemistry/question-539-answer-and-explanation.html#orQ7e5fP4KbyITm2.99
7. A small value for K, the equilibrium constant, indicates that A. the concentration of the un-ionized molecules must be relatively small compared with the ion concentrations B. the concentration of the ionized molecules must be larger than the ion concentrations C. the substance ionizes to a large degree D. the concentration of the un-ionized molecules must be relatively large compared with the ion concentrations E.
Correct Answer: D Explanation: (D) For Keq to be a small value, the numerator of the expression must be small compared with the denominator. Because the numerator is the product of the concentrations of the ion concentrations and the denominator is the product of the un-ionized molecules, the concentration of the un-ionized molecules must be relatively large compared with the ion concentrations. Unionzed molecules = reactents Ionized molecules = products Small K value is due to a larger reactent than products Read more at http://www.cracksat.net/sat2/chemistry/question-461-answer-and-explanation.html#dVLfv0wckQHwFrj7.99
19. When the following redox equation is balanced and all coefficients are reduced to lowest whole-number terms, what is the coefficient of H2O? HCl + KMnO4 → H2O + KCl + MnCl2 + Cl2 A. 1 B. 2 C. 5 D. 8 E. 16
Correct Answer: D Explanation: (D) HCl + KMnO4 → H2O + KCl + MnCl2 + Cl2 oxidation: 2Cl- → Cl2 + 2e- reduction: 8H+ + MnO4- + 5e- → Mn2+ + 4H2O 5 (oxidation reaction) and 2 (reduction reaction) will balance the e- gain and loss, giving 10Cl- → 5Cl2 + image: http://www.cracksat.net/sat2/chemistry/images2/00078.jpeg e- 16H+ + 2MnO4- + image: http://www.cracksat.net/sat2/chemistry/images2/00078.jpeg e- → 2Mn2+ + 8H2O Therefore 16HCl + 2KMnO4 → 8H2O + 2KCl + 2MnCl2 + 5Cl2 Read more at http://www.cracksat.net/sat2/chemistry/question-610-answer-and-explanation.html#mKUSDxq7RwbtlC8D.99
17. A nuclear reactor must include which of the following parts? I. Electric generator II. Fissionable fuel elements III. Moderator A. I only B. III only C. I and II only D. II and III only E. I, II, and III
Correct Answer: D Explanation: (D) I is not necessary for the reactor, but often nuclear energy is used to oper ate an electric generator. The others, II and III, are necessary for fuel and neutron-speed control, respectively. Read more at http://www.cracksat.net/sat2/chemistry/question-838-answer-and-explanation.html#cgp8WOh0PYtdpxwx.99
5. If the flame used to heat a flask is an orange color and blackens the bottom of the flask, what correction should you make to solve this problem? A. Move the flask farther from the flame. B. Move the flask closer to the flame. C. Allow less air into the collar of the burner. D. Allow more air into the collar of the burner. E. The problem is in the supply of the gas, and you cannot fix it.
Correct Answer: D Explanation: (D) One of the basic adjustments to a burner is to assure enough air is mixing with the gas to form a blue cone-shaped flame. With insufficient air, carbon deposits will form on the flask and the flame will be orange. Read more at http://www.cracksat.net/sat2/chemistry/question-533-answer-and-explanation.html#XdipuVpjWH8qRL9W.99
13. Two water solutions are made in the laboratory, one of glucose (molar mass = 180 g/mol), the other of sucrose (molar mass = 342 g/mol). If the glucose solution had 180 grams in 1,000 grams of water and the sucrose had 342 grams in 1,000 grams of water, which statement about the freezing points of the solutions is the most accurate? A. The glucose solution would have the lower freezing point. B. The sucrose solution would have the lower freezing point. C. The freezing point of the sucrose solution would be lowered twice as much as that of the glucose solution. D. Both solutions would have the same freezing point. E. The freezing points of the solutions would not be affected, because both solutes are nonpolar.
Correct Answer: D Explanation: (D) Since both solutions were 1 molal and neither compound ionized into more particles, the freezing points would be the same. Read more at http://www.cracksat.net/sat2/chemistry/question-604-answer-and-explanation.html#dpL2jPRJcD9tBQrX.99
9. For a laboratory experiment, a student placed sodium hydroxide crystals on a watch glass, assembled the titration equipment, and prepared a solution of 0.10 M sulfuric acid. Then he weighed 4 grams of sodium hydroxide and added it to enough water to make 1 liter of solution. What might be a source of error in the results of the titration? A. Some sulfuric acid evaporated. B. The sulfuric acid became more concentrated. C. The NaOH solution gained weight, thus increasing its molarity. D. The NaOH crystals gained H2O weight, thus making the solution less than 0.1 M. E. The evaporation of sulfuric acid solution countered the absorption of H2O by the NaOH solution.
Correct Answer: D Explanation: (D) Sodium hydroxide is hygroscopic and will attract water to its surface area. This water will influence its mass; consequently there will be less sodium hydroxide in the mass used. Read more at http://www.cracksat.net/sat2/chemistry/question-600-answer-and-explanation.html#dvpBL79Qi7zJuv0l.99
. The charring action of sulfuric acid is due to its being A. a strong acid B. an oxidizing agent C. a reducing agent D. a dehydrating agent E.
Correct Answer: D Explanation: (D) Sulfuric acid is a strong dehydrating agent and draws water to itself so strongly that is can char sucrose by withdrawing the hydrogen and oxygen from C12H22O11. Read more at http://www.cracksat.net/sat2/chemistry/question-499-answer-and-explanation.html#Ve4vMqIUSc5dSdSX.99
4. Which of the following is TRUE? A. The number of positive ions in solution equals the number of negative ions. B. The positive ions are called anions. C. The positive ions are called cathodes. D. The total positive charge equals the total negative charge in solution. E. None of the above
Correct Answer: D Explanation: (D) The only statement that is true is that the total positive charge in solution equals the total negative charge. The positive ions migrate to the negative pole called the cathode so they are called cations. Read more at http://www.cracksat.net/sat2/chemistry/question-483-answer-and-explanation.html#qViztv0zU0pcLrfv.99
Slight oxidation of a primary alcohol gives A. a ketone B. an organic acid C. an ether D. an aldehyde E. an ester
Correct Answer: D Explanation: (D) The slight oxidation of a primary alcohol produced an aldehyde Read more at http://www.cracksat.net/sat2/chemistry/question-515-answer-and-explanation.html#4ukwpzgb5A1kiKjm.99
11. The weakest of the bonds between molecules are coordinate covalent bonds BECAUSE coordinate covalent bonds represent the weak attractive force of the electrons of one molecule for the positively charged nucleus of another. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: D Explanation: (D) The weakest bonds between molecules are van der Waals forces, not coordinate covalent bonds. Read more at http://www.cracksat.net/sat2/chemistry/question-793-answer-and-explanation.html#9lt3Og5wYEEeFMS7.99
13. Which of these statements is NOT correct? A. In an exothermic reaction, ΔH is negative and the enthalpy decreases. B. In an endothermic reaction, ΔH is positive and the enthalpy increases. C. In a reaction where ΔG is negative, the forward reaction is spontaneous. D. In a reaction where ΔG is positive, ΔS may also be positive. E. In a reaction where ΔH is positive and ΔS is negative, the forward reaction is spontaneous.
Correct Answer: E Explanation: (E) All the first four statements are correct. The Gibbs free-energy equation is: ΔG = ΔH - TΔS In choice (E), if ΔH is positive and ΔS is negative, then ΔG will definitely be positive, which means that the forward reaction will not occur spontaneously. Read more at http://www.cracksat.net/sat2/chemistry/question-857-answer-and-explanation.html#pmLwCRwRmioSPSAJ.99
14. Which of the following is (are) true for this reaction? Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2(g) I. It is an oxidation-reduction reaction. II. Copper is oxidized. III. The oxidation number of nitrogen goes from +5 to +4. A. I only B. III only C. I and II only D. II and III only E. I, II, and III
Correct Answer: E Explanation: (E) I, II, and III are correct. Read more at http://www.cracksat.net/sat2/chemistry/question-835-answer-and-explanation.html#LmsEmEAUhbz8xZ76.99
10. The hydrid orbital form of carbon in acetylene is believed to be the sp form BECAUSE C2H2 is a linear compound with a triple bond between the carbons. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) Since acetylene is known to be a linear molecule with a triple bond between the two carbons, the sp orbitals along the central axis with the hydrogens bonded on either end fit the experimental evidence. Read more at http://www.cracksat.net/sat2/chemistry/question-792-answer-and-explanation.html#A1KOGx1rT8gzWlud.99
A synthesis reaction that is nonspontaneous and has a negative value for its heat of reaction will not occur until some heat is added BECAUSE nonspontaneous exothermic re actions need enough activation energy to get them started. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) The assertion is explained by the reason. The graphic display of this is: Read more at http://www.cracksat.net/sat2/chemistry/question-869-answer-and-explanation.html#Oyy4PQwscwKvHYqZ.99
If the forward reaction of an equi librium is exothermic, adding heat to the system favors the reverse reaction BECAUSE additional heat causes a stress on the system, and the system moves in the direction that releases the stress. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) The assertion is explained by the reason; both are true. Read more at http://www.cracksat.net/sat2/chemistry/question-875-answer-and-explanation.html#88P5IP73dQkyTzOt.99
The most electronegative elements in the periodic chart are found among nonmetals BECAUSE electronegativity is a measure of the ability of an atom to draw valence electrons to itself. A. T,T B. T,F C. F,T D. F,F E. T,T,CE
Correct Answer: E Explanation: (E) The assertion is true; the reason is true and explains why nonmetals have the highest electronegativity. Read more at http://www.cracksat.net/sat2/chemistry/question-877-answer-and-explanation.html#yQZD5Hd4Qk9fRCWL.99
The diagram represents a setup that may be used to prepare and collect A. NH3 B. NO C. H2 D. SO3 E. CO2
Correct Answer: E Explanation: (E) The other choices are wrong because: (A) is lighter than air (B) reacts with air (C) is lighter than air (D) needs heat to be evolved Read more at http://www.cracksat.net/sat2/chemistry/question-759-answer-and-explanation.html#Ad5jUwO6TPtUraf0.99
A compound whose molecular mass is 90.0 grams contains 40.0% carbon, 6.67% hydrogen, and 53.33% oxygen. What is the true formula of the compound? A. C2H2O4 B. CH2O4 C. C3H6O D. C3HO3 E. C3H6O3
Correct Answer: E Explanation: (E) To find the simple or empirical formula, divide each % by the element's atomic mass. Carbon 40 ÷ 12 = 3.333 Hydrogen 6.67 ÷ 1 = 6.67 Oxygen 53.33 ÷ 16 = 3.33 Next, divide each quotient by the smallest quotient in an attempt to get small whole numbers. 3.33 ÷ 3.33 = 1 C 6.67 ÷ 3.33 = 2 H 3.33 ÷ 3.33 = 1 O The simplest formula is CH2O, which has a molecular mass of 30. The true molecular mass is given as 90.0, which is three times the simplest. Therefore the true formula is C3H6O3. Read more at http://www.cracksat.net/sat2/chemistry/question-850-answer-and-explanation.html#H0rXlr8SMpVEFzLf.99
2. Two immiscible liquids, when shaken together vigorously, may form A. a solution B. a tincture C. a sediment D. a hydrated solution E. a colloidal dispersion
Correct Answer: E Explanation: (E) Two immiscible liquids, when shaken together vigorously, may each form small, colloidal-size particles, dispersed in the other liquid. Read more at http://www.cracksat.net/sat2/chemistry/question-569-answer-and-explanation.html#9cyy8Mr5oeEgKEKZ.99
20. The expression that can be used to designate a maximum of 3 moles of ions A. H2(g) B. CO2(g) C. 2N2O(g) D. 2NaCl (aq) E. H2SO4(dilute aq)
Correct Answer: E Explanation: (E) With complete ionization image: http://www.cracksat.net/sat2/chemistry/images2/00045.jpeg , or 3 mol of ions per mole of H2SO4. Read more at http://www.cracksat.net/sat2/chemistry/question-563-answer-and-explanation.html#Bys0mPFCbRfS2ApC.99
10. If 60. grams of NO is reacted with sufficient O2 to form NO2 that is removed during the reaction, how many grams of NO2 can be produced? (Molar masses: NO = 30. g/mol, NO2 = 46. g/mol) A. 46. B. 60. C. 92. D. 120 E. 180
Read more at http://www.cracksat.net/sat2/chemistry/question-601-answer-and-explanation.html#ookMB57FhgWOXd5G.99
Difference between strong acids and weak acids
Strong acids are highly ionized
When is the end point reached and the volume of the HCl recorded in this reaction?
The end point is reached when the color of the indicator disappears and does not return. The color will first disappear temporarily before the end point but finally will not return.
Which metal is oxidized
The most reactive metal CHeck the reactivity series
If K for the reaction H2 + I2 ↔ 2HI is equal to 45.9 at 450°C, and 1 mole of H2 and 1 mole of I2 are introduced into a 1-liter box at that temperature, what will be the expression for K at equilibrium?
[H2] = 1 mol/L [I2] = 1 mol/L [HI] = 0 At equilibrium (H2 + I2 ↔ 2HI) (Let x = moles/liter of H2 and I2 in HI form) [H2] = (1-x) mol/L [I2] = (1-x) mol/L [HI] = 2x mol/L Then, substituting the above values into the equation, you get: Correct answer B Read more at http://www.cracksat.net/sat2/chemistry/question-866-answer-and-explanation.html#yFgtRfZuWQkEgVH7.99
Dumas experiment
ratio of 1:8 by mass. This means that 1 gram of hydrogen combines with 8 grams of oxygen to form 9 grams of water. 9:1 - water to hydrogen by mass 9:8 - water to oxygen by mass synthesis of water
At the beginning of the reaction
the rate of reaction for reactents is the largest and then decreases vice versa for reactents/ at the end of a reaction