chem questions
What is the IUPAC name for the compound represented by the formula Mg(OH)2? a. Magnesium hydroxide. b. Magnesium dihydroxide. c. Magnesium (II) hydroxide. d. Magnesium (II) dihydroxide.
a. Magnesium hydroxide.
A scientist observes a chemical reaction as it takes place. How can the scientist so in order to tell if the reaction has achieved equilibrium? a. Measure concentrations of products and reactants over time. b. Monitor the temperature of the reaction over time. c. Measure the pH of the solution over time. d. Wait for the formation of a precipitate.
a. Measure concentrations of products and reactants over time.
Heat is added to a solution to a. increase the solubility of a solid solute. b. increase the solubility of a gas solute. c. increase the miscibility of the solution d. increase the degree of saturation of the solution.
a. increase the solubility of a solid solute.
What volume of 0.200M HCl will neutralize 10.0mL of 0.400M KOH? a. 40.0mL b. 20.0mL c. 8.00mL d. 5.00mL
b. 20.0mL
8 protons and 9 neutrons Which statement describes the element?? a. It is a nonmetal in group 2. b. It is a nonmetal in group 16. c. It is a metal in group 2. d. It is a nonmetal in group 17.
b. It is a nonmetal in group 16
Arrange the following elements in order of increasing electronegativity, from lowest to highest: F, K, Si, and S. a. F < K < S < Si b. K < Si < S < F c. Si < F < K < S d. S < Si < F < K
b. K < Si < S < F
Given the balanced chemical equation the reaction P₄ + 5O₂ → P₄O₁₀ What mass of oxygen is needed to completely react with 7.75 g P4 ? a. 2.00 grams b. 5.00grams c. 10.00 grams d. 40.00 grams
c. 10.00 grams
At STP, fluorine is a gas and iodine is a solid. Why? a. Fluorine has lower average kinetic energy than iodine. b. Fluorine has higher average kinetic energy than iodine. c. Fluorine has weaker intermolecular forces of attraction than iodine. d. Fluorine has stronger intermolecular forces of attraction than iodine.
c. Fluorine has weaker intermolecular forces of attraction than iodine.
Which statement describes the compound formed between sodium and oxygen? a. It is NaO2, which is ionic. b. It is NaO2, which is covalent. c. It is Na2O, which is ionic. d. It is Na2O, which is covalent.
c. It is Na2O, which is ionic.
When considering the energetics of the solution process, which process is always exothermic? a. Solute particles separate from one another. b. Solvent particles separate from one another. c. Solute and solvent particles form attractions for one another. d. Solution formation as a whole is always endothermic
c. Solute and solvent particles form attractions for one another.
When a set amount of marble chips (CaCO₃) is added to a small amount of dilute hydrochloric acid, a reaction occurs. What should be done to decrease the rate of reaction the next time the experiment is performed? a. Use more acid. b. Stir. c. Use larger marble chips. d. Add heat.
c. Use larger marble chips.
For the reaction 2SO₂(g) + O₂(g) ⇄ 2SO₃(g) + heat Which action will increase the concentration of SO₃? a. removing SO₂ b. increasing the temperature c. increasing the pressure d. adding a catalyst
c. increasing the pressure
Which atom has the largest radius? Justify your answer. a. Bromine b. Chlorine c. Selenium d. Sulfur
c. selenium
Consider this combustion reaction equation: C₄H₁₀ + O₂ → CO₂ +H₂O When the equation is balanced, what will be the coefficient of O2? a. 1 b. 7 c. 10 d. 13
d. 13
A student mixes two chemicals in a test tube. The test tube turns hot and bubbles appear. What indicators of chemical reaction is the student observing? a. Change in color and formation of precipitate. b. Change in color and formation of gas. c. Change in temperature and formation of precipitate. d. Change in temperature and formation of gas.
d. Change in temperature and formation of gas.
What causes the process of perspiration to be cooling for human skin? a. It involves condensation and is exothermic. b. It involves evaporation and is exothermic. c. It involves condensation and is endothermic. d. It involves evaporation and is endothermic
d. It involves evaporation and is endothermic
A compound consisting of 56.38% phosphorus and 43.62% oxygen has a molecular mass of 220 g/mole. What is the molecular formula of this compound? a. PO b. PO₂ c. P₂O₃ d. P₄O₆
d. P₄O₆
Based on hydroxide ion concentration, which unknown substance would be an acid? a. Substance A, [OH-] = 1.0 x 10⁻²M b. Substance B, [OH-] = 1.0 x 10⁻⁴M c. Substance C, [OH-] = 1.0 x 10⁻⁶M d. Substance D, [OH-] = 1.0 x 10⁻⁸M
d. Substance D, [OH-] = 1.0 x 10⁻⁸M
What causes an inflated balloon to shrink when it is cooled? a. because cooling the balloon causes gas to escape from the ball b. because cooling the balloon causes the gas molecules to collide more frequently c. because cooling the balloon causes gas molecules to become smaller d. because cooling the balloon causes the average kinetic energy of the gas molecules to decrease
d. because cooling the balloon causes the average kinetic energy of the gas molecules to decrease
An unknown substance is tested in the laboratory. The physical test results are listed below. ←Nonconductor of electricity ← Insoluble in water ←Soluble in oil ← Low melting point Based on these results, what is the unknown substance? a. ionic and polar. b. ionic and nonpolar. c. covalent and polar. d. covalent and nonpolar.
d. covalent and nonpolar.
1000 J of heat is added to 2 g of the following substances. Which one will experience the biggest change in temperature? a. aluminum b. copper c. iron d. lead
d. lead
How many moles are in 59.6 grams of BaSO₄ ? A 0.256 mole B 3.91 moles C 13.9 moles D 59.6 moles
A 0.256 mole
In a titration experiment, if 30.0 mL of an HCl solution reacts with 24.6 mL of a 0.50-M NaOH solution, what is the concentration of the HCl solution? A 0.41 M B 0.61 M C 1.5 M D 370 M
A 0.41 M
What is the molarity of a solution containing 20.0 g of sodium hydroxide dissolved in 1.00 L of solution? A 0.500 M B 0.400 M C 0.300 M D 0.200 M
A 0.500 M
A water sample was found to have a pH of 6 at 25°C. What is the hydroxide concentration in the water sample? A 1 X 10⁻⁸ M B 6 X 10⁻⁸ M C 1 X 10⁻⁶ M D 6 X 10⁻⁶ M
A 1 X 10⁻⁸ M
6.00 g of gold was heated from 20.0°C to 22.0°C. How much heat was applied to the gold? A 1.55 J B 15.5 J C 17.0 J D 32.5 J
A 1.55 J
A student has a beaker containing 55 g of water at 100°C. How much heat is needed to convert the water to steam? A 120,000 J B 18,000 J C 2,200 J D 330 J
A 120,000 J
What is the net charge of a magnesium ion? A 2+ B 1+ C 1− D 2−
A 2+
The specific heat of liquid water is 4.184 J/g◦C. Calculate the energy required to heat 10.0 g of water from 26.5◦C to 83.7◦C. A 2.39 × 10³J B None of these C 837 J D 572 J
A 2.39 × 10³J
The total pressure in a closed vessel containing N₂, O ₂and CO₂ is 30 atm. If the partial pressure of N₂ is 4 atm, and the partial pressure of O₂ is 6 atm, what is the partial pressure of CO₂ ? A 20 atm B 30 atm C 40 atm D 50 atm
A 20 atm
In the Bohr atom, what is the wavelength of light emitted when the electron goes from the n = 5 level to the n = 4 level? A 4051 nm B 91 nm C 2468 nm D 1823 nm
A 4051 nm
What is the volume of two moles of hydrogen gas at STP? A 44.8 L B 22.4 L C 11.2 L D 2.00 L
A 44.8 L
What is the percent by mass of iron in the compound Fe₂O₃ ? A 70% B 56% C 48% D 30%
A 70%
Methane (CH₄) is burned in oxygen according to this balanced chemical equation: CH₄(g) + 2O₂(g) → CO₂(g) + 2H₂O(g) What volume of carbon dioxide is formed when 9.36 liters of methane are burned in excess oxygen at STP? A 9.36 L B 15.0 L C 18.7 L D 22.4 L
A 9.36 L
Which equation represents a single replacement reaction that can occur? A F₂ + 2NaCl → 2NaF + Cl₂ B Cl₂ + 2NaF → 2NaCl F₂ C Cu + 2NaCl → CuCl₂ + 2Na D Zn + 2NaF → ZnF₂ + 2Na
A F₂ + 2NaCl → 2NaF + Cl₂
Which covalent bond is the most polar? A H-O B H-H C H-N D H-S
A H-O
What happens when energy is removed from liquid water? A Molecules slow down, and more hydrogen bonds are formed. B Molecules slow down, and more hydrogen bonds are broken. C Molecules move faster, and more hydrogen bonds are formed. D Molecules move faster, and more hydrogen bonds are broken.
A Molecules slow down, and more hydrogen bonds are formed.
Analysis shows a compound to be, by mass, 43.8% N, 6.2% H, and 50.0% O. Which is a possible molecular formula for the substance? A NH₄NO₂ B NH₄NO₃ C NH₃OH D N₂OH
A NH₄NO₂
Phenophthalein is an indicator that turns pink when added to a basic solution. In which solution would phenolphthalein turn pink? A NaOH B HCl C H₂O D NaCl
A NaOH
Consider this chemical equation: 2AgBr(s) + energy → 2Ag(s) + Br₂(l) Which is true about the reaction? A Silver is reduced. B Bromine is reduced. C Silver loses electrons. D Bromine gains electrons.
A Silver is reduced.
When a gamma ray is emitted by an element, what happens to the atomic mass and the atomic number? A The atomic mass stays the same, and the atomic number stays the same. B The atomic mass changes, and the atomic number stays the same. C The atomic mass stays the same, and the atomic number changes. D The atomic mass changes, and the atomic number changes.
A The atomic mass stays the same, and the atomic number stays the same.
A newly synthesized ionic compound is placed in water to make an aqueous solution. Which best describes the new ionic solution? A The ionic solution conducts electricity. B The ionic solution dissolves non-polar solutions. C The ionic solution cannot conduct electricity. D The ionic solution is a neutral solution.
A The ionic solution conducts electricity.
An open container of water is brought to a boil and heated until all of the water is converted to water vapor. Which describes the changes in the water molecules? A The molecules speed up and move farther apart. B The molecules speed up and move closer together. C The molecules slow down and move farther apart. D The molecules slow down and move closer together.
A The molecules speed up and move farther apart.
Which best describes the relationship between subatomic particles in any neutral atom? A The number of protons equals the number of electrons. B The number of protons equals the number of neutrons. C The number of neutrons equals the number of electrons. D The number of neutrons is greater than the number of protons.
A The number of protons equals the number of electrons.
The equation represents a chemical reaction at equilibrium. HCl (aq) + Mg (s) → MgCl₂ (aq) + H₂ (g) + heat What happens to the system when the temperature is decreased? A The reaction shifts toward the right, and the amount of hydrogen gas increases. B The reaction shifts toward the right, and the amount of hydrogen gas decreases. C The reaction shifts toward the left, and the amount of hydrogen gas increases. D The reaction shifts toward the left, and the amount of hydrogen gas decreases.
A The reaction shifts toward the right, and the amount of hydrogen gas increases.
Which example indicates that a chemical change has occurred? A When two aqueous solutions are mixed, a precipitate is formed. B As ammonium nitrate dissolves in water, it causes the temperature of the water to decrease. C Alcohol evaporates when left in an open container. D Water is added to blue copper(II) chloride solution. The resulting mixture is lighter blue in color.
A When two aqueous solutions are mixed, a precipitate is formed.
Which have the lowest electronegativities? A alkali metals B halogens C rare earth elements D transition metals
A alkali metals
When a radioactive atom emits an α particle, its mass number A decreases by four. B decreases by two. C increases by two. D increases by four.
A decreases by four.
The average kinetic energy of a sample of water molecules is - A increased as the temperature in increased B increased as the temperature is decreased C unaffected by temperature changes Dalways equal to zero
A increased as the temperature in increased
If the volume of an 18.5-g piece of metal is 2.35 cm³, what is the identity of the metal? A iron B lead C nickel D zinc
A iron
Collision theory states that A molecules must collide with the proper orientation in order to react. B all reactions become faster at lower temperature. C transition states are high energy. D reactions are irreversible
A molecules must collide with the proper
The molecular geometry of ammonia (NH³) is A pyramidal. B square planar. C tetrahedral. D linear.
A pyramidal.
The direct vaporization of a solid without passing through its liquid state is called A sublimation. B condensation. C solidification. D evaporation.
A sublimation.
Fluorine, chlorine and bromine are members of A the halogen group. B the alkali metal group. C the noble gas group. D the inert gas group.
A the halogen group.
An electron in an atom of hydrogen goes from energy level 6 to energy level 2. What is the wavelength of the electromagnetic radiation emitted? A. 410 nm B. 434 nm C. 486 nm D. 656 nm
A. 410 nm
What coefficients are required to balance this equation? _Fe²O³ + _CO → _Fe + _CO₂ A 2, 6, 3, 6 B 1, 3, 2, 3 C 1, 1, 2, 2 D 1, 1, 2, 1
B 1, 3, 2, 3
Consider this reaction: 3Mg(s) + 2H₃PO₄(aq) → Mg₃(PO₄)₂(s) + 3H₂(g) How many grams of magnesium phosphate should be produced if 5.40 grams of magnesium react with excess phosphoric acid? A 1.80 grams B 19.5 grams C 58.4 grams D 175 grams
B 19.5 grams
Metallic sodium reacts violently with water to form hydrogen and sodium hydroxide according to the balanced equation: 2Na + 2H₂O→2NaOH + H₂ How many moles of hydrogen gas are generated when 4.0 moles of sodium react with excess water? A 1.0 mole B 2.0 moles C 3.0 moles D 4.0 moles
B 2.0 moles
What is the pressure, in atmospheres, exerted by a 0.100 mol sample of oxygen in a 2.00-L container at 273°C? A 4.48 X 10⁻¹ atm B 2.24 X 10⁰ atm C 1.12 X 10³ atm D 2.24 X 10³ atm
B 2.24 X 10⁰ atm
Which equation is correctly balanced? A Cu + H₂SO₄ → CuSO₄ + H₂O + SO₂ B 2Na + 2H₂O → 2NaOH + H₂ C 2Fe + 3O₂ → Fe₂O₃ D 4Cu + S₈ → 8Cu₂S
B 2Na + 2H₂O → 2NaOH + H₂
Suppose that a hypothetical element consists of a mixture of two isotopes. One isotope, having a mass of 44.0, is present in 70 percent atomic abundance, while the other isotope, having a mass of 46.0, accounts for the other 30 percent. What should we expect the experimentally determined atomic weight for this hypothetical element to be? A 46.0 B 44.6 C 44.0 D 45.0
B 44.6
One mole of X contains how many molecules of X? A 2.24 × 102 molec B 6.023 × 1023 molec C 1.0 × 100 molec D 2.24 × 101 molec
B 6.023 × 1023 molec
How many valence electrons are in a Br⁻ ion? A 0 B 8 C 7 D 6
B 8
You can increase the rate of solvation by A heating the mixture. B All are correct. C powdering the solute. D stirring the mixture
B All are correct.
Identify the correct statement regarding the Kinetic Molecular Theory. A Gas particles are closely associated with each other. B As temperature decreases, this causes velocity to decrease. C Intermolecular forces are strong. D Collisions are effective (inelastic).
B As temperature decreases, this causes velocity to decrease.
Which best describes the current atomic theory? A Atoms consist of electrons circling in definite orbits around a positive nucleus. B Atoms are composed of electrons in a cloud around a positive nucleus. C Atoms can easily be split, at which time they become radioactive. D An atom's mass is determined by the mass of its neutrons.
B Atoms are composed of electrons in a cloud around a positive nucleus.
Which idea of John Dalton is no longer considered part of the modern view of atoms? A Atoms are extremely small. B Atoms of the same element have identical masses. C Atoms combine in simple whole number ratios to form compounds. D Atoms of different elements can combine in different ratios to form different compounds.
B Atoms of the same element have identical masses.
This balanced chemical equation represents a chemical reaction: 6NO + 4NH₃ → 5N₂ + 6H₂O What volume of NH₃ gas, at Standard Temperature and Pressure (STP), is required to react with 15.0 g of NO? A 5.68 L B 7.47 L C 10.0 L D 11.2 L
B B 7.47 L
Select one metal which will displace Sn from a compound and form metallic tin (Sn). A Cu B Cr C Ag D Hg
B Cr
A compound has an empirical formula of CH₂O and a molecular mass of 180 g. What is the compound's molecular formula? A C₃H₆O₃ B C₆H₁₂O₆ C C₆H₁₁O₇ D C₁₂H₂₂O₁₁
B C₆H₁₂O₆
Which occurs if an electron transitions from n = 5 to n = 2 in a hydrogen atom? A Energy is absorbed, and visible light is emitted. B Energy is released, and visible light is emitted. C Energy is released, and visible light is not emitted. D Energy is absorbed, and visible light is not emitted.
B Energy is released, and visible light is emitted.
What is the formula of gallium (Ga) sulfate? A Ga₃(SO₄)₂ B Ga²(SO₄)₃ C GaSO₄ D Ga₂SO₄
B Ga²(SO₄)₃
Which best explains why cations are smaller than the atoms from which they are formed? A The metallic atom gains electrons, causing a larger effective nuclear pull. B The metallic atom loses electrons, resulting in loss of an entire energy level. C The nonmetallic atom gains electrons, causing a larger effective nuclear pull. D The nonmetallic atom loses electrons, resulting in loss of an entire energy level.
B The metallic atom loses electrons, resulting in loss of an entire energy level.
What is the name of HCl ( aq)? A chloric acid B hydrochloric acid C hydrogen chloride D perchloric acid
B hydrochloric acid
What type of bonding is associated with compounds that have the following characteristics: •high melting points •conduct electricity in the molten state •solutions conduct electricity •normally crystalline solids at room temperature. A covalent B ionic C hydrogen D metallic
B ionic
What is the name of the compound PbO ? A lead oxide B lead(II) oxide C lead oxide(II) D lead(IV) oxide
B lead(II) oxide
A substance has a melting point of 14◦C and a boiling point of 78◦C. In what state is the substance at 78◦C? A solid and/or liquid B liquid and/or gas C solid D solid and/or gas
B liquid and/or gas
What energy level transition is indicated when the light emitted by a hydrogen atom has a wavelength of 103 nm? A n = 2 to n = 1 B n = 3 to n = 1 C n = 4 to n = 2 D n = 5 to n = 2
B n = 3 to n = 1
Which particle will complete this reaction? ⁵⁹₂₇Co + ___ → ⁶⁰₂₇Co A electron B neutron C nucleus D proton
B neutron
Which one of the following has the lowest electronegativity? A chlorine B sodium C oxygen D fluorine
B sodium
Solid chromium(II) reacts with oxygen gas to form solid CrO. What is this type of reaction? A decomposition B synthesis C single replacement D double replacement
B synthesis
Which of the following has the largest mass? A proton B α particle C electron D neutron
B α particle
Which atomic symbol represents an isotope of sulfur with 17 neutrons? A. ¹⁷₁₆X B. ³³₁₆X C.¹⁷₃₂X D.⁴⁹₃₂X
B. ³³₁₆X
Which is the electronic sonfiguration of calcium? A. 1s²2s²2p⁶3s²3p⁸ B. 1s²2s²2p⁶3s²3p⁶4s² C. 1s²2s²2p⁶3s²3p⁶3d² D. 1s²2s²2p⁶3s²3p⁶
B.1s²2s²2p⁶3s²3p⁶4s²
The half-life of phosphorus-32 is 14.30 days. How many milligrams of a 20.00 mg sample of phosphorus-32 will remain after 85.80 days? A 3.333 mg B 0.6250 mg C 0.3125 mg D 0.1563 mg
C 0.3125 mg
Gallium (atomic number 31) is in group 13 (IIIA). In addition to the s type electrons, it will have how many electrons in the 4p energy sublevel? A 13 B 3 C 1 D 2
C 1
How many grams of ice will melt at 0°C if the ice absorbs 420. J of energy? A 0.186 g B 0.795 g C 1.26 g D 4 5.38 10 g
C 1.26 g
How many grams of AlCl₃ are produced if 30.0 g of H₂ are produced? 2Al + 6HCl → 2AlCl₃ + 3H₂ The molar mass of AlCl3 is 133.33 g/mol. A 5390 g B 46.5 g C 1320 g D 0.0743 g
C 1320 g
Which electron configuration represents a transition element? A 1s²2s²2p³ B 1s²2s²2p⁶3s² C 1s²2s²2p⁶3s²3p⁶4s²3d⁷ D 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁴
C 1s²2s²2p⁶3s²3p⁶4s²3d⁷
How many molecules are contained in 55.0 g of H₂SO₄ ? A 0.561 molecule B 3.93 molecules C 3.38 X 10²³ molecules D 2.37 X 10²⁴ molecules
C 3.38 X 10²³ molecules
How many grams of KCl are necessary to prepare 1.50 liters of a 0.500-M solution of KCl? A 224 g B 74.6 g C 56.0 g D 24.9 g
C 56.0 g
Given the electronic configuration of 1s²2s²2p⁴ , how many electrons does this element have in its outer level? A 2 B 4 C 6 D 8
C 6
_ C₄H₁₀ (g) + _ O₂ (g) → _CO₂ (g) + _ H₂O (g), using the smallest possible integers. What is the coefficient of CO2? A 4 B 6 C 8 D 2
C 8
The compound formed between element X and oxygen has the chemical formula X₂O. Which element would X most likely represent? A Fe B Zn C Ag D Sn
C Ag
Which of the following metals or nonmetals are expected to displace Mn or Cl (respectively) from MnCl₂? A Cu should displace Mn. B I should displace Cl. C Ca should displace Mn. D Br should displace Cl.
C Ca should displace Mn
What is the chemical formula for calcium nitrate? A CaNO₃ B Ca(NO₂)₂ C Ca(NO₃)₂ D Ca₃N₂
C Ca(NO₃)₂
Which of the following molecules would have linear molecular geometry? A SO₂ B None of the molecules listed C HCN D H₂O
C HCN
Select the set of bonds below that lists in order an ionic bond, polar covalent bond, and a nonpolar covalent bond. A N O, O H, C H B Na S, C H, Br Br C K O, H F, C H D Br Br, C H, Na S
C K O, H F, C H
Consider this chemical equation: NH₃(aq) + HCl(aq) → NH⁺₄(aq) + Cl⁻(aq) In this reaction, why is the ammonia considered a base? A NH₃ increases the hydronium ion concentration. B NH₃ decreases the hydroxide ion concentration. C NH₃ accepts a proton. D NH₃ donates a proton.
C NH₃ accepts a proton.
This balanced equation represents a chemical reaction: 3Ag + 4HNO₃ → 3AgNO₃ + NO 2H₂O Which substance undergoes reduction? A Ag⁰ B H⁺ C N⁵⁺ D O²⁻
C N⁵⁺
Which is the correct formula for dinitrogen pentoxide? A N₄O B NO₂ C N₂O₅ D NO₄
C N₂O₅
How do the three isotopes Sn-116, Sn-118, and Sn-119 differ? A. Sn-116 has 166 neutrons, Sn-118 has 168 neutrons, and Sn-119 has 169 neutrons. B. Sn-116 has 116 neutrons, Sn-118 has 118 neutrons, and Sn-119 has 119 neutrons. C. Sn-116 has 66 neutrons, Sn-118 has 68 neutrons, and Sn-119 has 69 neutrons. D. Sn-116 has 50 neutrons, Sn-118 has 52 neutrons, and Sn-119 has 53 neutrons
C Sn-116 has 66 neutrons, Sn-118 has 68 neutrons, and Sn-119 has 69 neutrons.
Consider this oxidation-reduction reaction: 16H⁺ + 2MnO₄⁻ + 5Sn²⁺ → 5Sn⁴⁻ + 2Mn²⁺ + 8H₂O Which represents the oxidation half-reaction? A Sn⁴⁺ + 2e⁻ → Sn²⁺ B Mn⁶⁺ + 4e⁻ → Mn²⁺ C Sn²⁺ → Sn⁴⁺ + 2e⁻ D Mn → Mn²⁺ + 2e⁻
C Sn²⁺ → Sn⁴⁺ + 2e⁻
For the reaction A⁺(aq) + B⁻(aq) → AB(s) increasing the temperature increases the rate of the reaction. Which is the best explanation for this happening? A The pressure increases, which in turn increases the production of products. B The concentration of reactants increases with an increase in temperature. C The average kinetic energy increases, so the likelihood of more effective collisions between ions increases. D Systems are more stable at high temperatures.
C The average kinetic energy increases, so the likelihood of more effective collisions between ions increases.
What happens to the pressure of a constant mass of gas at constant temperature when the volume is doubled? A The pressure is doubled. B The pressure remains the same. C The pressure is reduced by 1/2 . D The pressure is reduced by 1/4 .
C The pressure is reduced by 1/2
Consider this balanced chemical equation: 2H₂O₂(aq) → 2H₂O(l) + O₂(g) Which will increase the rate of the reaction? A increasing pressure on the reaction B decreasing concentration of the reactants C adding a catalyst to the reaction D decreasing the temperature of the reaction
C adding a catalyst to the reaction
Why is potassium chloride able to dissolve in water? A because potassium ions are attracted to the partial negative charge of hydrogen B because potassium ions are attracted to the partial positive charge of hydrogen C because potassium ions are attracted to the partial negative charge of oxygen D because potassium ions are attracted to the partial positive charge of oxygen
C because potassium ions are attracted to the partial negative charge of oxygen
Real gases behave most nearly like ideal gases at A high pressures and low molar masses. B high temperatures and high pressures. C high temperatures and low pressures. D low temperatures and high pressures.
C high temperatures and low pressures.
Which pair of elements would most likely bond to form a covalently bonded compound? A sodium and fluorine B barium and chlorine C phosphorus and oxygen D magnesium and sulfur
C phosphorus and oxygen
Frequency is A the distance between successive peaks in a wave. B the height of the wave. C the number of waves passing a fixed point in one second. D the distance between a peak in a wave to the next trough
C the number of waves passing a fixed point
What is the oxidation number of the chromium atom in the Cr₂O₇²⁻ ion? A — 6 B — 4 C +4 D +6
D +6
Consider this reaction: 3Ca(s) +2H₃PO₄(aq)→ Ca₃(PO₄)₂(s) + 3H₂(g) How many moles of calcium are required to produce 60.0 g of calcium phosphate? A 0.145 mole B 0.194 mole C 0.387 mole D 0.581 mole
D 0.581 mole
What is the pH of a solution of KOH with a hydroxide concentration of [OH] = 1 X 10⁻⁴ M ? A —10 B —4 C 4 D 10
D 10
A magnesium (Mg) atom with a mass number of 25 contains A None of these B 25 protons, 13 neutrons and 25 electrons. C 25 protons, 25 neutrons and 25 electrons. D 12 protons, 13 neutrons and 12 electrons.
D 12 protons, 13 neutrons and 12 electrons.
Find the molar mass for Ba(OH)2. A 170.32 g/mol B 155.33 g/mol C 153.31 g/mol D 171.35 g/mo
D 171.35 g/mo
To what volume must 529 mL of 13 M Ca(OH)₂ solution be diluted to make a 3 M Ca(OH)₂ solution? A the correct answer is not given B 2.384 C 1.755 D 2.29233 L
D 2.29233 L
If a sample of magnesium has a mass of 60. g, how many moles of magnesium does the sample contain? A 1.1 moles B 1.2 moles C 2.0 moles D 2.5 moles
D 2.5 moles
Identify the isotope that has atoms with 12 neutrons, 10 protons, and 10 electrons. A 12Mg B 22Na C None of these D 22Ne
D 22Ne
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂ How many moles of carbon dioxide (CO₂) are produced when reacting 6.00 moles of butane (C₄H₁₀) in excess oxygen (O₂)? A 1.50 mol B 66.0 mol H 1060 mol D 24.0 mol
D 24.0 mol
An aqueous solution of silver nitrate is added to an aqueous solution of iron(II) chloride. Which is the net ionic equation for the reaction that occurs? A AgNO₂(aq) + FeCl(aq) → AgCl(s) + FeNO₂(aq) B 2AgNO₃(aq) + FeCl₂(aq) → 2AgCl(s) + Fe(NO₃)₂(aq) C 2Ag⁺¹(aq) + NO⁻¹₃(aq) + Fe⁺²(aq) + Cl₂(g) → 2AgCl(s) D 2Ag⁺(aq) + 2Cl⁻(aq) → 2AgCl(s)
D 2Ag⁺(aq) + 2Cl⁻(aq) → 2AgCl(s)
According to the equation 2H₂O(l)→ 2H₂(g) + O₂(g), what mass of H₂O is required to yield 22.4 L of O₂ at STP? A 12 g B 18 g C 24 g D 36 g
D 36 g
In the reaction Al2S3(s) + 6 HCl(aq) → 2 AlCl3(aq) + 3 H2S(g) how much HCl is used for each mole of AlCl3 formed? A 3 mol B 1 mol C 0 mol D 6 mol
D 6 mol
What is the nuclear composition of uranium-235? A 92 electrons + 143 protons B 92 protons + 143 electrons C 143 protons + 92 neutrons D 92 protons + 143 neutrons
D 92 protons + 143 neutrons
How does a single covalent bond between two carbon atoms compare to a double covalent bond between two carbon atoms? A A single covalent bond is stronger and has a longer bond length than a double covalent bond. B A single covalent bond is stronger and has a shorter bond length than a double covalent bond. C A single covalent bond is weaker and has a shorter bond length than a double covalent bond. D A single covalent bond is weaker and has a longer bond length than a double covalent bond.
D A single covalent bond is weaker and has a longer bond length than a double covalent bond.
When a chemical cold pack is activated, it becomes cool to the touch. What is happening in terms of energy? A An exothermic reaction is occurring, absorbing cold from its surroundings. B An exothermic reaction is occurring, releasing heat to its surroundings. C An endothermic reaction is occurring, releasing cold to its surroundings. D An endothermic reaction is occurring, absorbing heat from its surroundings.
D An endothermic reaction is occurring, absorbing heat from its surroundings.
How does the amount of heat energy change as a 250-g sample of water is heated from 5.0°C to 30.0°C? A The amount of heat energy increases, causing the water to sublime. B The amount of heat energy increases, causing the water to evaporate. C As the temperature increases, the amount of heat energy decreases. D As the temperature increases, the amount of heat energy increases.
D As the temperature increases, the amount of heat energy increases.
Which of these compounds will form a precipitate when mixed with an aqueous solution of sodium sulfate, Na₂SO₄? A LiNO₃ B KNO₃ C Mg(NO₃)₂ D Ba(NO₃)₂
D Ba(NO₃)₂
How are compounds with metallic bonds similar to ionic compounds? A. Both tend to have double and triple bonds. B. Both tend to have low boiling points. C. Both tend to have poor conductivity. D. Both tend to have high melting points.
D Both tend to have high melting points.
A compound consists of 65.45% C, 5.492% H, and 29.06% O on a mass basis and has a molar mass of 110 g/mol. Determine the molecular formula of the compound. A CH₃O B C₆H₆O₂ C C₅H₅O₂ D CHO
D CHO
Which correctly lists four atoms from smallest to largest radii? A I, Br, Cl, F B F, I, Br, Cl C Si, P, S, Cl D Cl, S, P, Si
D Cl, S, P, Si
Which of these elements has the greatest atomic radius? A. H B. N C. Cl D. Cs
D Cs
Which is a unique characteristic of the bonding between metal atoms? A Atoms require additional electrons to reach a stable octet. B Atoms must give away electrons to reach a stable octet. C Atoms share valence electrons only with neighboring atoms to reach a stable octet. D Delocalized electrons move among many atoms creating a sea of electrons.
D Delocalized electrons move among many atoms creating a sea of electrons.
Consider the spectrum for the hydrogen atom. In which situation will light be produced? A Electrons absorb energy as they move to an excited state. B Electrons release energy as they move to an excited state. C Electrons absorb energy as they return to the ground state. D Electrons release energy as they return to the ground state
D Electrons release energy as they return to the ground state
Which is the most polar molecule? A CH₄ B CF₄ C CO₂ D H₂O
D H₂O
What products are formed when the metal potassium is added to water? A K and H₂O B KOH and H₂O C K₂O and H₂ D KOH and H₂
D KOH and H₂
What is the chemical formula for magnesium bromate? A MgBr B MgBr₂ C MgBrO₃ D Mg(BrO₃)₂
D Mg(BrO₃)₂
When Na₂O reacts with H₂O, what is produced? A HNaO₂ B Na + H₂O C NaO + H₂ D NaOH
D NaOH
Which molecule contains a triple bond? A F₂ B O₂ C Cl₂ D N₂
D N₂
Which statement regarding red and green visible light is correct? A The speed of green light is greater than that of red light. B The wavelength of green light is longer than that of red light. C The energy of green light is lower than that of red light. D The frequency of green light is higher than that of red light.
D The frequency of green light is higher than that of red light.
Which one of the following statements is NOT a correct statement of the Law of Conservation of Mass? A Atoms are conserved in chemical reactions. B The mass of a system is conserved in a chemical reaction. C Matter can not be created nor destroyed. D The mass of a system is dependent upon chemical reactions that may occur.
D The mass of a system is dependent upon chemical reactions that may occur.
This equation represents a chemical reaction at equilibrium: 2SO₂ (g) + O₂ (g) → 2SO₃ (g) What will happen when the concentration of SO₃ is increased? A The reaction shifts to the right, and concentrations of SO₂ (g) and O₂ (g) decrease. B The reaction shifts to the right, and concentrations of SO₂ (g) and O₂ (g) increase. C The reaction shifts to the left, and concentrations of SO₂ (g) and O₂ (g) decrease. D The reaction shifts to the left, and concentrations of SO₂ (g) and O₂ (g) increase.
D The reaction shifts to the left, and concentrations of SO₂ (g) and O₂ (g) increase.
The gases helium, neon, and argon are in separate containers at 55°C. Which is true about the kinetic energy of the gases? A Helium has the lowest mass and therefore greatest kinetic energy. B They each have a different kinetic energy. C Argon has the greatest mass and therefore the greatest kinetic energy. D They all have the same average kinetic energy.
D They all have the same average kinetic energy.
The ion Cl− can best be described as A a neutral ion. B a metal ion. C a monatomic cation. D a monatomic anion.
D a monatomic anion.
Consider dissolving gases in water. Which of the following gases will become less soluble if the temperature of the water is raised? A H2 B O2 C He D all of these
D all of these
Which color of light would a hydrogen atom emit when an electron changes from the n = 5 level to the n = 2 level? A red B yellow C green D blue
D blue
Raising the temperature of a sample of water will typically (decrease/increase) the solubility of (all/some) dissolved gases. A increase, some B increase, all C decrease, some D decrease, all
D decrease, all
Which statement explains why the speed of some reactions is increased when the surface area of one or all the reactants is increased? A increasing surface area changes the electronegativity of the reactant particles B increasing surface area changes the concentration of the reactant particles C increasing surface area changes the conductivity of reactant particles D increasing surface area enables more reactant particles to collide
D increasing surface area enables more reactant particles to collide
Which will increase the solubility of most solid solutes? A decreasing the temperature B decreasing the amount of solvent at constant temperature C increasing the amount of solute at constant temperature D increasing the temperature
D increasing the temperature
Consider this reaction: NH₃(g) + HCl(g) → NH₄Cl(s) Which type of reaction does this equation represent? A combustion B decomposition C single replacement D synthesis
D synthesis
Generally, reaction rates increase when the temperature of the system is raised because A the bond energy of the reactants decreases as the temperature increases. B the concentration of reactants increases as the temperature increases. C the bond energy of the products decreases as the temperature increases. D the kinetic energy (and thus the speed) of the reactants increases as the temperature increases
D the kinetic energy (and thus the speed) of the reactants increases as the temperature increases
Based on the VSEPR theory, what is the molecular geometry of a molecule of PI₃ ? A linear B tetrahedral C trigonal planar D trigonal pyramidal
D trigonal pyramidal
Which weighs more: a mole of water or a mole of methane? A They both weigh the same. B The answer cannot be determined. C methane D water
D water
Which will complete this equation? ²³⁸₉₂U → ²³⁴₉₀Th + ___ A ⁰₋₁e B ²³⁸₉₂U C ¹₁H D ⁴₂He
D ⁴₂He
The half-life of a radioactive isotope is 20 minutes. What is the total amount of 1.00 g of sample of this isotope remaining after 1 hour? A. 0.500 g B. 0.333 g C 0.250 g D. 0.125 g
D. 0.125 g
Which statement compares the amount of energy neeeded to break the bonds in CaCl₂ and C₁₂H₂₂O₁₁? A. E₁>E₂ as CaCl₂ is a covalent compound B. E₁<E₂ as CaCl₂ is a covalent compound C. E₁>E₂ as CaCl₂ is an ionic compound D. E₁<E₂ as CaCl₂ is an ionic compound
D. E₁<E₂ as CaCl₂ is an ionic compound