Chemistry Lab Exam
How did the solution appear after you added test solution to the test tube filled with only copper sulfate(II) solution?
dark blue
After heating a solid, you observe that the mass has decreased and there has been a change in color. What type of reaction have you likely observed?
decomposition
Using the rules for naming molecular compounds described in the introduction, what is the name for the compound N2O4
dinitrogen tetroxide
A yellow precipitate is formed when combining two colorless solutions. What type of reaction have you likely observed?
double-displacement
Determine the electron geometry (eg) and molecular geometry (mg) of XeF4.
eg = octahedral, mg = square planar
Determine the electron geometry (eg) and molecular geometry (mg) of the underlined atom CH3OCH3.
eg = tetrahedral, mg = bent
Determine the electron geometry (eg) and molecular geometry (mg) of the underlined carbon in CH3OH.
eg = tetrahedral, mg = tetrahedral
Determine the electron geometry (eg) and molecular geometry (mg) of NI3.
eg = tetrahedral, mg = trigonal pyramidal
Determine the electron geometry (eg) and molecular geometry (mg) of BrCl3.
eg = trigonal bipyramidal, mg = T-shape
Determine the electron geometry (eg) and molecular geometry (mg) of ICl2-.
eg = trigonal bipyramidal, mg = linear
Determine the electron geometry (eg) and molecular geometry (mg) of KrF2.
eg = trigonal bipyramidal, mg = linear
Is the reaction of magnesium and hydrochloric acid exothermic or endothermic?
exothermic
Chemical Energy:
potential energy
Other Energy
Kinetic and thermal
What is the formula for the compound tetraphosphorus decoxide?
P4O10
In test tube #3, potassium permanganate was mixed with sodium bisulfite in basic solution. Identify the change that occurred.
The solution turned green.
Experiment 1: What container is the most precise for measuring the volume of a liquid?
graduated cylindar
What did you observe when you combined the sodium hydroxide and hydrochloric acid solutions?
The temperature increased, but no other visible signs were observed.
Describe what happens when solutions of NaOHNaOH and NiCl2NiCl2 are combined
When the solutions are combined a green solid is formed and the solution becomes very pale green in color instead of bright green.
KCl(aq)+CaS(aq)→
no reaction
Where are the substances required to perform the experiments located?
the materials shelf
What is the mathematical equation that represents Boyle's law?
𝑃×𝑉=constant
Extensive:
has a mass of 50.89 g, has a volume of 5.68
Why did the temperature of the flask increase when hydrochloric acid and zinc were combined?
he reaction was exothermic
What type of bonding occurs in zinc(II) chloride, ZnCl2ZnCl2?
ionic
Which subatomic particle(s) are found in the nucleus of the atom?
protons, neutrons
What is the maximum number of s orbitals that are possible in a given shell?
1
Identify the number of bonding pairs and lone pairs of electrons in F2.
1 bonding pair and 6 lone pairs
What are the subscripts in the empirical formula of this compound? Enter the subscripts for C, H, and O, respectively, separated by commas (e.g., 5,6,7).
1,2,1
Suppose 2.00 atm2.00 atm of an ideal gas occupies a volume of 80 mL.80 mL. What pressure will the gas have when the volume is expanded to 100 mL100 mL at the same temperature?
1.6
What is the value of the bond angles in SiH4SiH4?
109.5 degrees
An atom has a mass number of 24 and 13 neutrons. What is the atomic number of this atom?
11
The atomic number of carbon is 6. What is the mass number of a carbon atom with 5 neutrons?
11
What is the value of the bond angles in COH2COH2?
120 degrees
Compute 1240.64/12.51240.64/12.5. Round the answer appropriately.
1240.64 / 12.5 = 99.3
Suppose you perform the reaction of magnesium and hydrochloric acid in a different constant pressure calorimeter with a calorimeter constant of 12.75 J/oC. The initial temperature in the calorimeter is 22.5 oC and the final temperature after the reaction is 33.7 oC. What is the value of qcal?
143 J
An atom of sulfur is represented by 3316S1633S. How many neutrons are in the nucleus of this atom?
17
What is the value of the bond angle in I3−I3−?
180 degrees
What is the stoichiometric ratio between sodium carbonate and carbon dioxide?
1:1
Now that we have put coefficients of 3 in front of CaSO4CaSO4 and CaCl2CaCl2, what coefficient should go in front of AlCl3AlCl3 to balance both the ClCl atoms and the AlAl atoms? 3CaSO4+?AlCl3→3CaCl2+Al2(SO4)3
2
What value of l is represented by a d orbital?
2
Calculate the mass of 1.00×10^24 (a septillion) molecules of water.
29.9 g
The green precipitate in Experiment 4 is nickel hydroxide. Which of the following equations describes the observed reaction?
2NaOH(aq)+NiCl2(aq)⟶2NaCl(aq)+Ni(OH)2(s)2NaOH(aq)+NiCl2(aq)⟶2NaCl(aq)+Ni(OH)2(s)
Notice that "SO4SO4" appears in two different places in this chemical equation. SO42−SO42− is a polyatomic ion called "sulfate." What number should be placed in front of CaSO4CaSO4 to give the same total number of sulfate ions on each side of the equation? ?CaSO4+AlCl3→CaCl2+Al2(SO4)3
3
Now that we have put a coefficient of 3 in front of CaSO4CaSO4, what coefficient should go in front of CaCl2CaCl2 to balance calcium (CaCa)? 3CaSO4+AlCl3→?CaCl2+Al2(SO4)3
3
What is the maximum number of p orbitals that are possible in a given shell?
3
Under what conditions was the maximum amount of precipitate formed by the reaction between sodium sulfide and copper(II) sulfate?
3 mL CuSO4 + 3 mL Na2S
Which of the following set of quantum numbers (ordered n�, ℓℓ, mℓ�ℓ, ms�s) are possible for an electron in an atom?
3, 1, 0, -1/2 , 3, 2, 2, -1/2 , 5, 3, 0, 1/2
Compute 3.5 × 4.486973.5 × 4.48697. Round the answer appropriately.
3.5 × 4.48697 = 3.5 × 4.48697= 16
NaOH(aq)+Fe(NO3)3(aq)→
3NaOH(aq)+Fe(NO3)3(aq)→Fe(OH)3(s)+3NaNO3(aq)
Identify the number of bonding pairs and lone pairs of electrons in carbon dioxide.
4 bonding pairs and 4 lone pairs
Compute 4.659×10^4−2.14×10^4. Round the answer appropriately.
4.659 × 10^4− 2.14 × 10^4 = 2.52*10^4
Give the nuclear symbol for the isotope of potassium for which A=40�=40 ?
40/19 K
How many grams of H2H2 are needed to produce 13.58 gg of NH3
45
What is the maximum number of d orbitals that are possible in a given shell?
5
Atmospheric pressure yesterday was given as 0.875 atm. Express this pressure in units of torr and also in kilopascals (kPa), respectively.
665 torr and 88.7 kPa
What is the maximum number of f orbitals that are possible in a given shell?
7
The specific heat of water is 4.18 J/(g⋅∘C)J/(g⋅∘C). Calculate the molar heat capacity of water.
75.2
How many moles of NH3NH3 can be produced from 12.0 molmol of H2H2 and excess N2N2?
8.00
How many orbitals are there in the third shell (n=3�=3)?
9
Compute 9.3456+2140.56 Round the answer appropriately.
9.3456+2140.56= 2149.91
What is the value of the smallest bond angle in XeCl4XeCl4?
90 degrees
In test tube #4, potassium permanganate was mixed with sodium bisulfite in neutral solution. Identify the change that occurred.
A black precipitate formed.
When the volume of 0.1 M Na2S exceeded the volume of 0.1 M CuSO4, what happened to the supernatant upon the addition of the test solution and what does that indicate?
A precipitate formed, indicating that Na2S was the excess reactant.
Experiment 4: How can you tell that a reaction happened in the double-displacement reaction?
A precipitate formed.
Did a reaction happen in the Erlenmeyer flask? How can you tell?
A reaction happened because there was an increase in temperature after the addition of NaOH.
How can you tell that the reaction from Experiment 1 is a synthesis reaction?
A single product forms from two reactants.
Deep water fish are highly sought after for home aquariums. However, these fish are hard to transport to the surface safely. Why do you think that is?
As the water pressure decreases, the air in their swim bladders expands until they burst.
In the decomposition reaction, what happened to the solid in the crucible as it was heated?
The solid turned from green to black.
Experiment 4: In the double-displacement reaction, which observation describes what happened when the contents of the two beakers were mixed?
The solution became pale green and a green solid formed.
Place the following types of electromagnetic radiation in order of increasing frequency. ultraviolet light microwaves gamma rays
microwaves < ultraviolet light < gamma rays
What is the gas formed in the hydrochloric acid and sodium carbonate reaction?
C02
What is the formula for the compound methane
CH4
How many molecules (not moles) of NH3NH3 are produced from 2.53×10−4 gg of H2
molecules
Suppose you were to heat the copper in argon gas instead of atmospheric gases. Given that argon is relatively inert, which of the following would you expect if you were to heat pure copper in the presence of argon gas?
Copper oxide would not form and the mass would not change.
Suppose you conducted a similar experiment using helium gas. Given that helium is much lighter than the gases used in this lab, what would you expect the relationship between the volume and pressure of helium to be?
The volume and pressure of helium would be inversely proportional, just like it is for propane and butane.
Would the volume be different if the gas was argon (under the same conditions)?
The volume would be the same if the gas was argon because the ideal gas law is dependent on the number of moles of the gas and not the mass.
Why was mass lost from the crucible during the reactions?
The water of hydration was released as water vapor.
In the decomposition reaction, what happened to the mass of the contents of the crucible after heating?
It decreased.
What is the main advantage of using the water displacement method to measure the volume of a metal versus using the length measurements?
Water displacement can be used for irregularly shaped metals such as lumps.
What is the formula for the compound nitrogen monoxide?
NO
Experiment 2: In the decomposition reaction, mass was lost. Where did the mass go?
Water vapor and carbon dioxide gas were released into the atmosphere.
Which of the following resonance structures for OCN- will contribute most to the correct structure of OCN-?
O-C≡N, with three lone pairs on O and one lone pair on N
What formula can you use to calculate the oxidation state (OS) of Mn in a charged polyatomic ion containing oxygen?
OS=charge of the ion−# of oxygen atoms×(−2)
Where did the extra mass come from? (Hint: The final product is magnesium oxide.)
Oxygen from the air was used by the magnesium to form magnesium oxide.
The law of conservation of mass states that matter is neither created nor destroyed in a chemical reaction. How do you explain iron nails getting heavier as they rust?
When rusting, the iron in the nails reacts with oxygen in the air, and therefore the mass increases.
What observations did you make when the hydrochloric acid and zinc were combined?
When the hydrochloric acid and zinc were combined, bubbles formed, the temperature of the mixture rose, and the pressure increased.
According to the law of conservation of mass, matter cannot be created nor destroyed. Do your results from this experiment agree with this law?
Yes, the results agree with the law of conservation of mass because the mass is the same before and after the reaction when the flask is closed.
Using the rules for naming molecular compounds described in the introduction, what is the name for the compound NO2NO2?
nitrogen dioxide
An unknown element, XX, reacts with rubidium to form the compound Rb2XRb2X. In other compounds this element also can accommodate up to 12 electrons rather than the usual octet. What element could XX be?
Se
Experiment 2: Why did you need to zero the balance before you added the water to the beaker?
So that only the mass of the water was recorded and not the mass of the container and the water.
KI(aq)+BaS(aq)→
no reaction
Why do you think you were required to take three measurements for each experiment instead of just one?
Taking three measurements minimizes the contribution of experimental error.
Conclusions: Which is a more precise (or exact) measuring tool, the balance or the graduated cylinder? Explain your answer.
The balance because it gives more significant figures.
Acid-base reactions are hard to observe because they usually do not provide any visual cues. In this lab, you used a thermometer to determine that a reaction occurred between hydrochloric acid and sodium hydroxide. How could you detect the changes caused by this reaction in a classroom laboratory if you did not have access to a thermometer?
You can touch the flask and see if the flask warms up during the reaction.
Where are the lab supplies located in the lab?
on the shelf above the workbench
What can be said about the mass of the 1.0 M HCl and 1.0 M NaOH solutions after they were combined?
The combined mass of the 1 M HCl and 1 M NaOH solution was equal to the sum of their individual masses.
When hydrochloric acid and zinc were combined, the flask was sealed and thus no gas could escape from the flask. Why did the pressure decrease as the temperature decreased?
The gas behaved as an ideal gas where pressure is proportional to temperature.
What could account for the change in mass that you observed after opening the flask at the end of the reaction between hydrochloric acid and sodium carbonate?
The gas produced in the reaction escaped the flask, resulting in a decrease in mass.
In the synthesis reaction, what happened to the mass of the contents of the crucible after heating?
The mass increased.
When you made your test solution, what chemicals did you add?
ammonia and zinc sulfate
Identify the discovery that Thomson made.
an electron
Consider the following graph of the number of moles of CO2CO2 produced as a function of the number of moles of Na2CO3Na2CO3 added. How does the graph appear?
The number of moles of CO2CO2 increases linearly with increasing Na2CO3Na2CO3 until around 0.06 mol of Na2CO3,Na2CO3, at which point, the amount of CO2CO2 produced is independent of the amount of Na2CO3Na2CO3 added.
Intensive
begins to melt at 1083.4 degrees C, has a density of 8.9 g/ml, and is reddish brown in color
How did the solution appear after you mixed 5 mL of 0.1 M copper(II) sulfate with 1 mL of 0.1 M sodium sulfide?
blue with a black precipitate
Experiment 3: In the single-displacement reaction, immediately after adding the zinc to the hydrochloric acid solution, the temperature and pressure increased. As the solution returned to room temperature, what happened?
The pressure decreased.
In the single-displacement reaction, what happened to the temperature and pressure immediately after adding the zinc to the hydrochloric acid solution?
The pressure increased and the temperature increased.
Use the flowchart in the figure to name HClO4(aq)
perchloric acid
What are the possible orbitals for n = 4?
s, p, d, f
What ions are present in an aqueous solution of NaOH?
cation: Na+Na+ anion: OH−
A solid sample of metal is dropped into an acidic solution. Bubbles form as the metal is dissolved. What kind of reaction have you likely observed?
single-displacement
To place something into a container you must
click on the material or instrument and drag it onto the container.
Give the systematic name for the compound Co2(SO4)3
cobalt(III) sulfate
How did the solution appear after you mixed 3 mL of 0.1 M copper(II) sulfate with 3 mL of 0.1 M sodium sulfide?
colorless with a black precipitate
How did the solution appear after you added test solution to the test tube filled with only sodium sulfide solution?
colorless with a white precipitate
How did the solution appear after you added the test solution to the supernatant from the reaction of 3 mL of 0.1 M copper(II) sulfate with 3 mL of 0.1 M sodium sulfide?
colorless with no precipitate
Identify the discovery that Millikan made.
the charge of a single electron
The behavior of a gas depends on what four variables?
volume, pressure, temperature, and amount
The color of a substance depends not only on the oxidation state of the atoms, but also on the structure. A solution of K2CrO4 is yellow and a solution of K2Cr2O7 is orange. Chromium has the same oxidation state in both compounds despite the difference in color. What is the oxidation state of chromium?
+6
What are the possible values of mℓ�ℓ for an electron in a d orbital?
-2,-1,0,1,2
A 100.0 mL sample of 0.300 M NaOH is mixed with a 100.0 mL sample of 0.300 M HNO3 in a coffee cup calorimeter. If both solutions were initially at 35.00°C and the temperature of the resulting solution was recorded as 37.00°C, determine the ΔH°rxn (in units of kJ/mol NaOH) for the neutralization reaction between aqueous NaOH and HNO3. The specific heat capacity of water = 4.18 J/g°C. Assume 1) that no heat is lost to the calorimeter or the surroundings, and 2) that the density and the heat capacity of the resulting solution are the same as water.
-55.7 kJ/mol NaOH
What is the formal charge on the oxygen atom in NONO?
0
What is the only possible value of mℓ�ℓ for an electron in an s orbital?
0
What value of l is represented by a s orbital?
0
For n = 3, what are the possible values for l?
0, 1, 2
A flask contains 0.330 molmol of liquid bromine, Br2Br2. Determine the number of bromine molecules present in the flask
1.99×1023 molecules
The conversion factor relating feet to meters is 1ft=0.305m1ft=0.305m. Keep in mind that when using conversion factors, you want to make sure that like units cancel leaving you with the units you need. You have been told that a certain house is 164 m2m2 in area. How much is this in square feet?
1760
Which of the following represents the balanced equation for the synthesis reaction of MgO?
2Mg(s)+O2(g)⟶2MgO(s)2Mg(s)+O2(g)⟶2MgO(s)
A 1.40-gg gas sample occupies 607 mLmL at 21 ∘C∘C and 1.00 atmatm. What is the molar mass of the gas?
55.7 g/mol
The fuel used in many disposable lighters is liquid butane, C4H10C4H10. How many carbon atoms (CC) are in 1.50 gg of butane?
6.22 x 10^22 carbon atoms
The conversion factor relating miles to meters is 1mile=1610m. The speed of light is 3.00×108 m/s3.00×108 m/s. How fast is this in miles per hour (miles/hmiles/h)?
6.71×108 miles/hmiles/h
The molecular formula mass of this compound is 240 amU . What are the subscripts in the actual molecular formula? Enter the subscripts for C, H, and O, respectively, separated by commas (e.g., 5,6,7).
8,16,8
What are the expected bond angles in ICl4+ICl4+?
90, 120, 180
In test tube #4, potassium permanganate was mixed with sodium bisulfite in neutral solution. Use the Oxidation States of Manganese and Colors table from the Background to identify the manganese product formed based on your observations.
A black precipitate formed; therefore the product was MnO2.
Which of the following statements is TRUE? Part of the Bohr model proposed that electrons in the hydrogen atom are located in "stationary states" or particular orbits around the nucleus. The emission spectrum of a particular element is always the same and can be used to identify the element. An orbital is the volume in which we are most likely to find an electron. The uncertainty principle states that we can never know both the exact location and speed of an electron. All of the above are true.
All of the above
Which of the following statements is TRUE?
Atoms are roughly spherical because when all of the different shaped orbitals are overlapped, they take on a spherical shape.
What are the main ideas in Dalton's atomic theory?
Atoms of one element cannot change into atoms of another element., All atoms of a given element have the same mass and other properties that distinguish them from the atoms of other elements, Each element is composed of tiny, indestructible particles called atoms., Atoms combine in simple, whole number ratios to form compounds.
What observations did you make when the hydrochloric acid and zinc were combined? What do these observations tell you about this single displacement reaction?
Bubbles formed, the temperature of the mixture rose, and the pressure increased. The formation of bubbles and the increase in pressure indicate that a gas has formed.
In the single-displacement reaction, what happened to the hydrochloric acid solution when zinc was added?
Bubbles formed.
Why did the solution bubble when the Na2CO3 was added?
CO2 gas was produced.
Enter the formula for the compound copper(II) phosphate.
CU3(PO4)2
The color change of the copper(II) carbonate hydroxide as it was heated can help identify the product. Use the list of copper compounds to identify the product.
CuO
The reported molar mass for the copper oxide formed in Experiment 1 is 79.55 g/mol.79.55 g/mol. What is the molecular formula of the oxide formed in Experiment 1? The molar mass of copper is 63.55 g/mol63.55 g/mol and the molar mass of oxygen is 16.00 g/mol.
CuO
Which of the following represents the balanced chemical equation for this reaction?
CuSO4⋅5H2O(s)→CuSO4(s)+5H2O(g)
Why is density referred to as a characteristic property of matter?
Density can be used to identify the type of matter.
Why don't we observe the wavelength of everyday macroscopic objects?
Due to the large mass of macroscopic objects, the deBroglie wavelength is extremely small. The wavelength is so small that it is impossible to detect compared to the size of the object.
What is the formula for sulfurous acid
H2SO3
What is the formula for chlorous acid?
HClO2
When instructed to record observations, data, or notes, where should you record the information?
In a notebook or other document to reference later when completing the assignment.
Create a graph of the number of moles of CO2CO2 formed (y-axis) versus the number of moles of Na2CO3Na2CO3 added (x-axis). Use the graph to identify the limiting reactant in each of the flasks.
In the first four flasks, Na2CO3Na2CO3 is the limiting reactant. In the last three flasks, H2SO4H2SO4 is the limiting reactant.
Who was the scientist that developed the law of conservation of mass?
Lavoisier
Lithium is the only metal that reacts with nitrogen gas at room temperature to form lithium nitride. To avoid oxide formation, the reaction is performed under pure nitrogen gas. Given the experimental data in the table below, what is the empirical formula of lithium nitride? The molar mass of lithium is 6.94 g/mol and that of nitrogen is 14.01 g/mol. Mass of empty crucible 74.000 g Mass of crucible with lithium before reaction 75.500 g Mass of crucible after the reaction 76.513 g
Li3N
Which of the following represents the balanced chemical equation for this reaction?
MgCl2⋅6H2O(s)→MgCl2(s)+6H2O(g)
Enter the formula for the compound magnesium oxide.
MgO
Similar to copper, magnesium also reacts with the oxygen in the air when heated to form magnesium oxide. Given the experimental data in the table, what is the empirical formula of magnesium oxide? The molar mass of magnesium is 24.31 g/mol24.31 g/mol and the molar mass of oxygen is 16.00 g/mol.16.00 g/mol. mass of empty crucible64.000 g64.000 gmass of crucible with magnesium before reaction65.125 g65.125 gmass of crucible and contents after heating65.866 g
MgO
Suppose a student conducts an experiment in which Mn2+Mn2+ reacts with another substance and forms MnO2−4.MnO42−. Is Mn2+Mn2+ the oxidizing or the reducing agent and how many electrons does manganese gain or lose in this reaction?
Mn2+Mn2+ is the reducing agent and it loses 4 electrons.
NiBr2(aq)+Na2CO3(aq)→
NiBr2(aq)+Na2CO3(aq)→NiCO3(s)+2NaBr(aq)
Which of the following is true of the internal energy of a system and its surroundings during an energy exchange with a negative ΔEsysΔ�sys?
The internal energy of the system decreases and the internal energy of the surroundings increases
Why is the mass corresponding to a mole of one element different from the mass corresponding to a mole of another element?
The mass corresponding to a mole of one element is different from the mass corresponding to a mole of another element because the mass of an atom of each element is different. A mole is a specific number of atoms; so the heavier the mass of each atom, the heavier the mass of one mole of atoms.
In a classroom laboratory, what will be the initial change in the gas variables when the volume is decreased?
The pressure and temperature will increase.
What happened to the pressure inside the Erlenmeyer flask, as compared to normal atmospheric pressure, after the addition of sodium carbonate to the hydrochloric acid solution?
The pressure increased.
Zinc reacts with hydrochloric acid resulting in the formation of zinc chloride and hydrogen gas. What do you expect will happen to the pressure inside the reaction flask if it is closed with a rubber stopper before the reaction?
The pressure will increase.
What could account for the change in pressure inside the flask that you observed after the addition of the sodium carbonate to the hydrochloric acid solution?
The reaction between hydrochloric acid and sodium carbonate produced a gas that was trapped inside the closed flask.
Why does the flask have to be closed during the hydrochloric acid and sodium carbonate reaction?
The reaction between hydrochloric acid and sodium carbonate produces a gas. To conserve the mass, the gas has to be trapped inside the flask.
After an equal number of milliliters of Na2S and CuSO4 were mixed, what happened to the supernatant upon the addition of the test solution and what does that indicate?
The solution remained colorless without a precipitate forming, indicating that neither reagent was in excess.
When the volume of 0.1 M CuSO4 exceeded the volume of 0.1 M Na2S, what happened to the supernatant upon the addition of the test solution and what does that indicate?
The solution turned blue, indicating that CuSO4 was the excess reactant.
In test tube #3, potassium permanganate was mixed with sodium bisulfite in basic solution. Use the Oxidation States of Manganese and Colors table from the Background to identify the manganese product formed based on your observations.
The solution turned green; therefore the product was MnO2−4.
In test tube #5, potassium permanganate was mixed with sodium bisulfite in acidic solution. Identify the change that occurred.
The solution turned pale pink.
In test tube #5, potassium permanganate was mixed with sodium bisulfite in acidic solution. Use the Oxidation States of Manganese and Colors table from the Background to identify the manganese product formed based on your observations.
The solution turned pale pink; therefore the product was Mn2+.
What did you observe after adding the sodium carbonate to the hydrochloric acid?
There was bubbling in the Erlenmeyer flask.
What happened to the contents of the flask after adding sodium carbonate to the sulfuric acid?
They bubbled as gas was released.
Suppose a student plotted the pressure of propane in atm (y-axis) versus the volume of propane in mL (x-axis). What shape do you expect the graph to have?
Triangle
Bubble wrap is often used to protect fragile objects during shipping. Bubble wrap tends to pop when stepped onto or squeezed. How can you explain this using Boyle's law?
When you squeeze the bubbles, you decrease the volume. So the air pressure inside of the bubbles keep increasing until it results to popping.
According to the law of conservation of mass, matter cannot be created nor destroyed. Do your results from this experiment agree with this law?
Yes, the results agree with the law of conservation of mass because the mass is the same before and after the reaction.
A graph of mass versus volume for iron is shown. The density of iron is equal to the slope of the graph. Is the graph consistent with what you know about density?
Yes. The density is constant, therefore as the mass increases, the volume increases.
What is the name of the acid whose formula is H2CO3
carbonic acid
How did the solution appear after you mixed 1 mL of 0.1 M copper(II) sulfate with 5 mL of 0.1 M sodium sulfide?
colorless with a black precipitate
Boron trifluoride (BF3BF3) is used as a catalyst in many organic synthesis reactions. What type of bonding occurs between the atoms of a BF3BF3 molecule?
covalent
Determine the electron geometry (eg) and molecular geometry (mg) of the underlined atom H2CO.
eg = trigonal planar, eg = trigonal planar
How many grams of NH3NH3 can be produced from 4.45 molmol of N2N2 and excess H2
gNH3
Place the following types of electromagnetic radiation in order of increasing wavelength.
gamma rays < ultraviolet light < microwaves
What is the name of the acid whose formula is HI
hydroiodic acid
Give the systematic name for the compound Mg(NO3)2
magnesium nitrate
What type of bonding occurs in a sample of pure chromium, CrCr? In other words, how is one chromium atom held to another chromium atom?
metallic
Which of the following visible colors of light has the longest wavelength?
red
What is the molecular geometry of IF4-?
square planar
What shape would you expect for XeF4XeF4?
square planar
What are the variables that Robert Boyle held constant during his experiments on gases?
temperature and amount
You are given a sample resembling copper. Which of the following properties could be used to help determine whether the sample is really copper?
the density of the sample, the melting point of the sample
Which of the following visible colors of light has the highest frequency?
violet
Place the following types of electromagnetic radiation in order of decreasing energy.x-rays radio waves infrared light
x-rays > infrared light > radio waves
Suppose you use a coffee cup calorimeter to measure the heat released in the neutralization reaction between sodium hydroxide and hydrochloric acid. Given the data in the table, how much heat was released or absorbed in the reaction? Mass of empty calorimeter (g) 12.500 Initial temperature in the calorimeter (oC) 22.0 Final temperature in the calorimeter (oC) 27.5 Mass of the calorimeter and its contents after the reaction (g) 110.740 Calorimeter constant (J/oC) 24.7
−2.40×103 J
