Labs 1-10 quizzes

Which metal in the table below is most likely your unknown metal? Metal Density (g/cm3) zinc 7.13 tin 7.28 copper 8.96 silver 10.49 lead 11.36 Select one: a. copper b. zinc c. silver d. lead

b. zinc

What was the mass of SiO2 in the powdered mixture? Select one: a. 85.428 g b. 1.158 g c. 15.775 g d. 23.148 g

c. 15.775 g

Select the balanced equation for the reaction of HCl(aq) with Mg(s) to produce H2(g) and MgCl2(aq) using the data from the table. Substance Mass Mg 12.15 g HCl 36.46 g MgCl2 47.60 g H2 1.01 g Select one: a. 2Mg(s)+2HCl(aq)⟶MgCl2(aq)+H2(g) b. Mg(s)+2HCl(aq)⟶MgCl2(aq)+2H2(g) c. Mg(s)+2HCl(aq)⟶MgCl2(aq)+H2(g) d. 2Mg(s)+HCl(aq)⟶2MgCl2(aq)+H2(g)

c. Mg(s)+2HCl(aq)⟶MgCl2(aq)+H2(g)

Which answer for the value of absolute zero is closest to your measured value? Select one: a. -459.51 °C b. -0.00 °C c. -32.95 °C d. -273.16 °C

d. -273.16 °C

What is the enthalpy of reaction using the data in trial 2? Choose the closest answer. Select one: a. -31.7 kJ/mol b. 4.760 kJ/mol c. 482 kJ/mol d. -450 kJ/mol

d. -450 kJ/mol

What is the heat of reaction released or absorbed in trial 2? Choose the closest answer. Select one: a. -3560 J b. 6450 J c. 4760 J d. -4640 J

d. -4640 J

Given that the temperature in kelvins is equal to the temperature in degrees Celsius plus 273, what is absolute zero in kelvins? Select one: a. -527.00 b. 32.00 c. -273.15 d. 0.00

d. 0.00

How many moles of magnesium were used in trial 2? The molar mass of magnesium is 24.305 g/mol. Choose the closest answer. Select one: a. 2.83 moles b. 0.00617 moles c. 0.0144 moles d. 0.0103 moles

d. 0.0103 moles

What element is most likely present in the sample tested below? (Gray flame) Select one: a. strontium b. calcium c. copper(II) d. magnesium

d. magnesium

What is the source of the blue color of the solution after the reaction? Select one: a. the silver nitrate solution (AgNO3) b. aqueous copper ions (Cu2+) c. the solid copper (Cu) d. aqueous silver ions (Ag+)

b. aqueous copper ions (Cu2+)

Experiment 1: What was the color of the copper oxide after heating? Select one: a. blue b. black c. green d. orange

b. black

What color flame did lead nitrate produce? Select one: a. green b. blue c. purple d. yellow-red

b. blue

Which compound produced a purple flame? Select one: a. barium nitrate b. potassium nitrate c. calcium nitrate d. strontium nitrate

b. potassium nitrate

In Experiment 1, what volume did the propane gas occupy after the addition of 40 mL of water? Select one: a. 190 mL b. 210 mL c. 274 mL d. 40 mL

c. 274 mL

Which compound produced a light blue flame? Select one: a. magnesium nitrate b. potassium nitrate c. arsenic acid d. manganese nitrate

c. arsenic acid

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? Select one: a. single displacement b. synthesis c. decomposition d. double displacement

c. decomposition

Suppose you did a similar experiment in which volume was held constant and pressure was allowed to vary with temperature. The measured value of absolute zero would be _____. Select one: a. dependent on the identity of the gas b. higher c. identical d. lower

c. identical

What was the mass of just the contents in the calorimeter in trial 2? Choose the closest answer. Select one: a. 18.600 g b. 46.132 g c. 50.138 g d. 68.829 g

b. 46.132 g

What happens to the volume of a gas as the temperature approaches infinity? Select one: a. It approaches zero. b. It approaches infinity. c. It depends on the identity of the gas. d. It remains constant.

b. It approaches infinity.

In the synthesis reaction, what happened to the mass of the contents of the crucible after heating? Select one: a. It decreased. b. It increased. c. This information was not determined in this experiment. d. It was unchanged.

b. It increased.

In the decomposition reaction, what was the change in mass of the contents of the crucible after heating? Choose the closest answer. Select one: a. The mass increased by 3.327 g. b. The mass decreased by 3.327 g. c. The mass increased by 1.673 g. d. The mass decreased by 1.403 g.

. The mass decreased by 1.403 g.

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 of helium and the pressure to be? Select one: a. periodic, because helium is lighter b. inversely proportional, just like for propane and butane c. exponential, because helium is lighter d. directly proportional, just like for propane and butane

b. inversely proportional, just like for propane and butane

How many moles of solid silver were produced in the reaction? The atomic mass of silver is 107.87 g/mol. Select one: a. 0.01624 mol Ag b. 4.335 mol Ag c. 0.03147 mol Ag d. 3.392 mol Ag

c. 0.03147 mol Ag

What was the final pressure of the gas after inserting the gas syringe? Select one: a. 0.80 atm b. 1.50 atm c. 1.00 atm d. 0.50 atm

c. 1.00 atm

What was the mass of the ammonium chloride in the powdered mixture? Select one: a. 2.122 g b. 10.252 g c. 1.256 g d. 4.788 g

c. 1.256 g

What was the change in temperature in trial 2? Choose the closest answer. Select one: a. 30.3 °C b. 43.2 °C c. 23.4 °C d. 21.5 °C

c. 23.4 °C

Suppose that magnesium would react exactly the same as copper in this experiment. How many grams of magnesium would have been used in the reaction if 1.000 g of silver were produced? The atomic mass of magnesium is 24.31 g/mol, and the atomic mass of silver is 107.87 g/mol. Select one: a. 2.563 g b. 0.1127 g c. 2.000 g d. 0.2254 g

b. 0.1127 g

Experiment 2: How many moles of water were lost during the heating? The molar mass of water is 18.015 g/mol. Choose the closest answer. Select one: a. 0.1001 moles b. 0.1475 moles c. 0.02460 moles d. 0.8553 moles

b. 0.1475 moles

How much water did 15 g of aluminum displace? Select one: a. 1.85 mL b. 5.5 mL c. 2.54 mL d. 7.40 mL

b. 5.5 mL

Which of the following statements is true? Select one: a. Only one electron can be excited at a time. b. An electron may fall back to ground state in a single step or in multiple steps. c. Each element emits a single, characteristic wavelength of light during the flame test. d. Excited electrons do not return to ground state until they move away from the heat of the flame.

b. An electron may fall back to ground state in a single step or in multiple steps.

What is the ground state of an element? Select one: a. It is the arrangement of electrons that occurs after one or more electrons becomes excited. b. It is the most energetically favorable arrangement of the element's electrons. c. It is the most energetically favorable arrangement of the element's protons. d. It is the arrangement of electrons that occurs at room temperature or below.

b. It is the most energetically favorable arrangement of the element's electrons.

The mean velocity of molecules in a gas is equal to a constant times the square root of the temperature. What happens to the velocity of the molecules at absolute zero? Select one: a. The velocity is constant. b. The molecules stop. c. The velocity slows to 17 m/s. d. The molecules accelerate.

b. The molecules stop.

What happened to the color of the solution after the addition of copper? Select one: a. The solution turned white. b. The solution turned light blue. c. The solution turned red. d. The color of the solution remained unchanged.

b. The solution turned light blue.

What was the color of the magnesium chloride hydrate compound before heating? Select one: a. green b. gray c. black d. blue

b. gray

What color flame did zinc produce? Select one: a. purple b. gray-green c. light blue d. red

b. gray-green

Immediately after adding the zinc in the single-displacement reaction, the temperature and pressure increased. As the solution returned to room temperature, what happened? Select one: a. The solution turned green. b. The pressure increased. c. The pressure decreased. d. The pressure remained constant.

c. The pressure decreased

What was the volume of the gas at 0.0 °C? NOTE: The total volume of the gas equals the volume of the gas in the syringe plus the volume of the flask (182 mL). Pick the closest answer. Select one: a. 58.6 mL b. 150.0 mL c. 182.0 mL d. 210.9 mL

d. 210.9 mL

What was the mass of 30.00 mL of ethanol? Select one: a. 15.786 g b. 54.000 g c. 77.679 g d. 23.670 g

d. 23.670 g

In Experiment 1, what is the relationship between the volume occupied by propane and its pressure? Select one: a. As the volume of propane decreased, the pressure increased. b. As the volume of propane increased, the pressure increased. c. As the volume of propane decreased, the pressure was constant. d. As the volume of propane decreased, the pressure decreased.

a. As the volume of propane decreased, the pressure increased.

What type of calorimeter did you use in this experiment? Select one: a. a constant pressure calorimeter b. a constant temperature calorimeter c. a bomb calorimeter d. a constant volume calorimeter

a. a constant pressure calorimeter

A flame test could be used to distinguish which of the following two substances most easily? Select one: a. copper(II) nitrate and calcium nitrate b. lithium nitrate and strontium nitrate c. arsenic acid and lead nitrate d. bismuth and lead nitrate

a. copper(II) nitrate and calcium nitrate

For which compound was the flame produced not a shade of green? Select one: a. lithium nitrate b. copper-(II) nitrate c. manganese nitrate d. barium nitrate

a. lithium nitrate

Which element or compound produced a white-gray flame? Select one: a. magnesium b. bismuth c. arsenic acid d. potassium

a. magnesium

You measured the mass of three different volumes of ethanol. What was the total volume of ethanol used for each of the three mass measurements? Select one: a. 61.80 mL, 69.80 mL, 77.68 mL b. 10.00 mL, 20.00 mL, 30.00 mL c. 10.00 g, 20.00 g, 30.00 g d. 10.00 mL, 10.00 mL, 10.00 mL

b. 10.00 mL, 20.00 mL, 30.00 mL

In the single-displacement reaction, what happened to the hydrochloric acid solution when zinc was added? Select one: a. A precipitate formed. b. The color changed from green to clear. c. Bubbles formed. d. The color changed from clear to green.

c. Bubbles formed

If the silver in the beaker contained water during your last weighing, how would this affect your results? Select one: a. The water would prevent the silver from reacting with the copper. b. The water would cause silver to weigh less, leading to an incorrect calculation of the mole ratios in the reaction. c. The silver would appear to weigh more, leading to an incorrect calculation of the mole ratios in the reaction. d. The silver would react with the water to form silver hydroxide.

c. The silver would appear to weigh more, leading to an incorrect calculation of the mole ratios in the reaction.

Which element or compound did not produce a red or pink flame? Select one: a. calcium sulfate b. lithium nitrate c. magnesium nitrate d. strontium nitrate

c. magnesium nitrate

What color flame did strontium produce? Select one: a. yellow b. white c. pink d. green

c. pink

Select the reaction equation for the reaction between copper and silver ions that is closest to your experimental values. Select one: a. 0.016Cu(s)+0.032Ag+(aq)⟶Cu2+(aq)+Ag(s) b. Cu(s)+0.016Ag+(aq)⟶0.032Cu2+(aq)+Ag(s) c. Cu(s)+Ag+(aq)⟶0.016Cu2+(aq)+0.032Ag(s) d. 0.016Cu(s)+0.032Ag+(aq)⟶0.016Cu2+(aq)+0.032Ag(s)

d. 0.016Cu(s)+0.032Ag+(aq)⟶0.016Cu2+(aq)+0.032Ag(s)

What was the mass of the copper used in the reaction? Select one: a. 185.000 g b. 391.450 g c. 5.000 g d. 1.000 g

d. 1.000 g

In Experiment 2, what volume did the butane gas occupy after the addition of 20 mL of water? Select one: a. 230 mL b. 150 mL c. 110 mL d. 294 mL

d. 294 mL

The green precipitate in Experiment 4 is nickel hydroxide. Which of the following equations describes the observed reaction? Select one: a. 2NaOH(aq)+NiCl2(aq)⟶2NaCl(aq)+NiOH(s) b. NaOH(aq)+NiCl2(aq)⟶NaCl(aq)+Ni(OH)2(s) c. NaOH(aq)+NiCl2(aq)⟶Ni(OH)2(s) d. 2NaOH(aq)+NiCl2(aq)⟶2NaCl(aq)+Ni(OH)2(s)

d. 2NaOH(aq)+NiCl2(aq)⟶2NaCl(aq)+Ni(OH)2(s)

What was the mass of the beaker together with the silver nitrate? Choose the closest answer. Select one: a. 185.000 g b. 110.000 g c. 388.450 g d. 330.634 g

d. 330.634 g

Experiment 2: What color was the copper (II) sulfate pentahydrate before heating? Select one: a. black b. white c. yellow d. blue

d. blue

What was the color of the copper sulfate compound before heating? Select one: a. white b. black c. green d. blue

d. blue

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 below, how much heat was released or absorbed in the reaction? Mass of empty calorimeter (g) 12.500 Initial temperature in the calorimeter (°C) 22.0 Final temperature in the calorimeter (°C) 27.5 Mass of the calorimeter and its contents after the reaction (g) 110.740 Calorimeter constant (J/°C) 24.7 Select one: a. -2400 J b. 2400 J c. 11000 J d. -2200 J

a. -2400 J

How many moles of copper were used in the reaction? The atomic mass of copper is 63.55 g/mol. Select one: a. 0.01574 mol Cu b. 6.156 mol Cu c. 0.03148 mol Cu d. 4.335 mol Cu

a. 0.01574 mol Cu

What was the mass of the empty beaker? Select one: a. 110.000 g b. 50.250 g c. 388.450 g d. 390.840 g

a. 110.000 g

What was the mass of the empty calorimeter? Note: The size of containers in the lab may vary. Pick the answer that is closest to yours. Select one: a. 18.600 g b. 68.600 g c. 54.000 g d. 68.921 g

a. 18.600 g

Deep water fish such as the ones in the figure below are highly sought after for home aquariums. However, these fish are hard to transport to the surface safely. Why do you think that is? Select one: a. As the water pressure decreases, the air in their swim bladders expands until they burst. b. As the water pressure decreases, the air in their swim bladders compresses until they burst. c. As the water pressure decreases, there is not enough oxygen for the fish in the water. d. As the water pressure increases, the air in their swim bladders compresses until they burst.

a. As the water pressure decreases, the air in their swim bladders expands until they burst.

How did your data collected in Experiment 1 with propane gas compare to the data you collected in Experiment 2 using butane? Select one: a. Both experiments produced the same data. b. The pressure values from propane gas were higher than for butane gas. c. The two experiments produced very different data. d. The pressure values from propane gas were lower than for butane gas.

a. Both experiments produced the same data.

What happens to the volume of a gas as the temperature is reduced? Select one: a. It decreases. b. It increases. c. It depends on the identity of the gas. d. It remains constant.

a. It decreases.

Suppose you chose the other gas to measure. How would you expect the value of absolute zero measured from the experiment to compare to the one you measured? Select one: a. It will be the same. b. It will be higher. c. It depends on the identity of the gas. d. It will be lower.

a. It will be the same.

molecules will interact with each other. Supposing that the interactions between the molecules are attractive, why would this introduce errors? Select one: a. The molecules would tend to be closer together at lower temperatures, leading to a lower-than-expected volume. b. This would not introduce an error. c. Larger molecules show greater attraction to each other than smaller molecules do. d. The molecules would tend to move faster at lower temperatures.

a. The molecules would tend to be closer together at lower temperatures, leading to a lower-than-expected volume.

In a real gas, as the temperature decreases, it is possible to cause a liquid to form. How would the formation of a liquid phase affect the measurement of absolute zero using the methodology employed in this experiment? Select one: a. The volume of the liquid does not change much as the temperature is reduced, leading to errors in the measurement of the volume-temperature relationship. b. The volume of the liquid would change very easily as the temperature is reduced, but the amount of change depends on the identity of the gas. c. The volume of the liquid would change very easily as the temperature is reduced, leading to errors in the measurement of the volume-temperature relationship. d. The volume of the liquid changes in the same proportion to temperature as the gas, leading to no error in the measurement of the volume-temperature relationship.

a. The volume of the liquid does not change much as the temperature is reduced, leading to errors in the measurement of the volume-temperature relationship.

What is the purpose of weighing the empty beaker? Select one: a. The weight of the empty beaker can be subtracted out after the reaction is complete to determine the mass of the products of the reaction. b. The weight of the empty beaker can be used to calculate the amount of reactants that can be added for the experiment. c. The weight of the empty beaker can be used as a positive control. d. The weight of the empty beaker is not essential to the calculations in this experiment.

a. The weight of the empty beaker can be subtracted out after the reaction is complete to determine the mass of the products of the reaction.

A yellow precipitate is formed when combining two colorless solutions. What type of reaction have you likely observed? Select one: a. double displacement b. decomposition c. single displacement d. synthesis

a. double displacement

What was the mass of magnesium used in the second trial? Choose the closest answer. Select one: a. 0.350 g b. 0.250 g c. 0.500 g d. 0.150 g

b. 0.250 g

In Experiment 1, what was the pressure of the propane gas in the Erlenmeyer flask before the addition of any water? Select one: a. 3.00 atm b. 1.00 atm c. 0.00 atm d. 1.15 atm

b. 1.00 atm

In Experiment 2, what was the pressure of the butane gas in the Erlenmeyer flask after the addition of 40 mL of water? Select one: a. 2.14 atm b. 1.146 atm c. 1.00 atm d. 1.068 atm

b. 1.146 atm

In Experiment 1, what volume did the propane gas occupy after the addition of 80 mL of water? Select one: a. 170 mL b. 234 mL c. 80 mL d. 0 mL

b. 234 mL

What was the volume of the gas at 80.0 °C? NOTE: The total volume of the gas equals the volume of the gas in the syringe plus the volume of the flask (182 mL). Pick the closest answer. Select one: a. 280.0 mL b. 272.7 mL c. 150.0 mL d. 119.7 mL

b. 272.7 mL

What was the mass of silver produced from the reaction? Choose the closest answer. Select one: a. 391.843 g b. 3.395 g c. 185.000 g d. 188.395 g

b. 3.395 g

Select the reaction equation for the reaction between copper and silver ions using the smallest whole number coefficients. Select one: a. 2Cu(s)+Ag+(aq)⟶2Cu2+(aq)+Ag(s) b. Cu(s)+2Ag+(aq)⟶Cu2+(aq)+2Ag(s) c. 5Cu(s)+2Ag+(aq)⟶5Cu2+(aq)+2Ag(s) d. 2Cu(s)+26Ag+(aq)⟶2Cu2+(aq)+2Ag(s)

b. Cu(s)+2Ag+(aq)⟶Cu2+(aq)+2Ag(s)

What is the mole to mole relationship between copper and zinc for the following reaction? Cu2+(aq)+Zn(s)⟶Cu(s)+Zn2+(aq) Select one: a. The relationship cannot be determined from the equation. b. It is a 1:1 relationship. c. It is a 1:2 relationship. d. It is a 2:1 relationship.

b. It is a 1:1 relationship.

What does the symbol (aq) represent when it is next to an compound? Select one: a. The compound is in the liquid state in solution. b. The compound is in the aqueous state, which means it is in an aqueous solution. c. The compound is in the solid state, which means it is not aqueous. d. The compound is in the gaseous state in solution.

b. The compound is in the aqueous state, which means it is in an aqueous solution.

Symbols such as (s) or (aq) written in parentheses next to an atom, ion, or a compound indicate Select one: a. the solubility of the atom, ion, or compound. b. the physical state of the atom, ion, or compound. c. the charge of the atom, ion, or compound. d. the molarity of the atom, ion, or compound.

b. the physical state of the atom, ion, or compound.

What are the four variables that can be altered in a gas sample? Select one: a. speed, volume, temperature, and number of moles b. volume, pressure, temperature, and amount c. volume, density, velocity, and temperature d. effusion, pressure, number of moles, and diffusion

b. volume, pressure, temperature, and amount

Given that the temperature in Fahrenheit is equal to 9/5 × (temperature in Celsius) + 32, what is absolute zero in degrees Fahrenheit? Select one: a. 32 b. -273 c. -460 d. 0

c. -460

In Experiment 1, what was the pressure of the propane gas in the Erlenmeyer flask after the addition of 20 mL of water? Select one: a. 2.14 atm b. 1.467 atm c. 1.068 atm d. 1.00 atm

c. 1.068 atm

What happens to the solid copper and the aqueous silver from the silver nitrate solution during the course of the reaction? Select one: a. The copper changed from an aqueous ion form to a solid, metallic state. The metallic silver from the silver nitrate solution became aqueous ions. b. The copper changed from a solid, metallic, unreacted state to an aqueous ion form. The metallic silver from the silver nitrate solution became aqueous ions. c. The copper changed from a solid, metallic, unreacted state to an aqueous ion form. The aqueous silver ions from the silver nitrate solution became solid, metallic silver. d. The copper changed from an aqueous ion form to a solid, metallic state. The aqueous silver ions from the silver nitrate solution became solid, metallic silver.

c. The copper changed from a solid, metallic, unreacted state to an aqueous ion form. The aqueous silver ions from the silver nitrate solution became solid, metallic silver.

You added 1.25 atm of gas. Why was the final pressure of the gas after adding the gas syringe equal to 1.00 atm? Select one: a. The needle of the syringe was cold, which caused the volume of the gas to contract. b. When the syringe was inserted, gas escaped from the flask. c. The gas expanded to fill the combined volume of the syringe and the flask. d. The pressure of the gas was constant before and after adding the syringe.

c. The gas expanded to fill the combined volume of the syringe and the flask.

In a classroom laboratory, what will be the initial change in the gas variables when the volume is decreased? Select one: a. The pressure will increase. b. The temperature will decrease. c. The pressure and temperature will increase. d. The amount and temperature will increase.

c. The pressure and temperature will increase.

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? Select one: a. The gas was converted into a solid. b. The gas entered the liquid, similar to a carbonated beverage. c. The produced gas behaved as an ideal gas where pressure is proportional to temperature. d. The temperature probe was not sensitive to this change.

c. The produced gas behaved as an ideal gas where pressure is proportional to temperature.

Did potassium nitrate and potassium dihydrogen arsenate produce similar colored flames? Select one: a. No, potassium nitrate produced pale yellow-green flames and potassium dihydrogen arsenate produced red flames. b. Yes, both compounds produced red flames. c. Yes, both compounds produced blue-purple flames. d. No, potassium nitrate produced purple flames and potassium dihydrogen arsenate produced yellow flames.

c. Yes, both compounds produced blue-purple flames.

What are the variables that Robert Boyle held constant during his experiments on gases? Select one: a. volume and pressure b. volume and temperature c. temperature and amount d. amount and pressure

c. temperature and amount

In Experiment 2, what was the pressure of the butane gas in the Erlenmeyer flask before the addition of any water? Select one: a. 3.00 atm b. 0.00 atm c. 1.15 atm d. 1.00 atm

d. 1.00 atm

Suppose you perform the reaction of magnesium and hydrochloric acid in a different constant pressure calorimeter with a calorimeter constant of 12.75 J/°C. The initial temperature in the calorimeter is 22.5 °C and the final temperature after the reaction is 33.7 °C. What is the value of qcal? Select one: a. -430 J b. 287 J c. -143 J d. 143 J

d. 143 J

What is the mole to mole relationship between the copper and silver? Select one: a. 2:10 b. 2:1 c. 1:1 d. 1:2

d. 1:2

How many grams of copper would you need to add if you wanted to produce 8.000 grams of silver? The atomic mass of copper is 63.55 g/mol, and the atomic mass of silver is 107.87 g/mol. Select one: a. 12.357 g of copper b. 4.000 g of copper c. 4.713 g of copper d. 2.357 g of copper

d. 2.357 g of copper

In Experiment 2, what volume did the butane gas occupy after the addition of 60 mL of water? Select one: a. 150 mL b. 70 mL c. 190 mL d. 254 mL

d. 254 mL

In Experiment 1, what volume did the propane gas occupy in the Erlenmeyer flask before the addition of any water? Select one: a. 20 mL b. 0.0 mL c. 250 mL d. 314 mL

d. 314 mL

What was the final temperature in the third trial? Select one: a. 21.5 °C b. 43.2 °C c. 34.5 °C d. 54.2 °C

d. 54.2 °C

What was the total mass of the calorimeter and its contents in the third trial? Choose the closest answer. Select one: a. 68.738 g b. 18.600 g c. 68.829 g d. 63.921 g

d. 63.921 g

Why do certain elements produce color when heated in a flame? Select one: a. Electrons absorb energy from the flame and turn into photons of light. b. Electrons absorb energy from the flame and become excited, which causes them to emit light. c. Electrons are in a constant state of excitation that causes them to emit light. d. Electrons absorb energy from the flame and become excited. Upon returning to the ground state, they emit light.

d. Electrons absorb energy from the flame and become excited. Upon returning to the ground state, they emit light.

What can you conclude based on the data that you collected from Experiments 1 and 2? Select one: a. Gases behave differently with respect to pressure and volume depending on the identity of the gas. b. Gases behave differently with respect to pressure and volume regardless of the identity of the gas. c. Gases behave similarly with respect to pressure but not with respect to volume regardless of the identity of the gas. d. Gases behave similarly with respect to pressure and volume regardless of the identity of the gas.

d. Gases behave similarly with respect to pressure and volume regardless of the identity of the gas.

In the enrichment of uranium for nuclear reactors, a gas called uranium hexafluoride (UF6) is generated and then placed in large gas centrifuges to separate different isotopes of uranium. Suppose you were to perform the same experiment with uranium hexafluoride. Given that uranium hexafluoride is much heavier than either of the gases used in this experiment, how would you expect the value of absolute zero measured from the experiment to compare to the one you measured? Select one: a. It will be higher. b. It will be lower. c. It depends on the identity of the gas. d. It will be the same.

d. It will be the same.

What is the mathematical equation that represents Boyle's Law? Select one: a. constant×P×V=R×T b. PV=nRT c. P/V=constant d. P×V=constant

d. P×V=constant

What does the symbol (s) represent when it is next to an atom? Select one: a. The atom is in the liquid state. b. The atom is a charged salt. c. The atom is selenium. d. The atom is in the solid state.

d. The atom is in the solid state.

In both experiments, what accounts for the change in pressure you observed as you changed the volume of the gas? Select one: a. The volume of the gas does not account for the changes in the pressure. b. When a gas is in a larger volume, the molecules have more space and bump into the walls of the flask more, thereby exerting a greater pressure. c. When a gas is in a smaller volume, the molecules have more space in the flask, thereby exerting a smaller pressure. d. When a gas is in a smaller volume, the molecules are more confined and bump into the walls of the flask more, thereby exerting a greater pressure.

d. When a gas is in a smaller volume, the molecules are more confined and bump into the walls of the flask more, thereby exerting a greater pressure.

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? Select one: a. double displacement b. decomposition c. synthesis d. single displacement

d. single displacement

What was the mass of the empty graduated cylinder? Choose the mass that is closest to the observed value. Select one: a. 75.000 g b. 65.000 g c. 105.000 g d. 85.000 g

a. 75.000g

What was the mass of the ethanol plus the graduated cylinder when 20.00 mL of ethanol was added? Select one: a. 90.780 g b. 98.670 g c. 61.893 g d. 77.679 g

a. 90.780 g

How many grams of magnesium chloride hydrate were added to the crucible before heating? Select one: a. 3.000 g b. 5.000 g c. 9.000 g d. 7.000 g

b. 5.000 g

Experiment 1: What was the mass of the empty crucible? Note: The size of containers in the lab can vary. Pick the answer that is closest to yours. Select one: a. 90.000 g b. 35.000 g c. 98.000 g d. 45.000 g

b. 35.000 g

What was the mass of the beaker with the sodium chloride after evaporating the water? Select one: a. 26.891 g b. 38.710 g c. 102.125 g d. 96.125 g

b. 38.710 g

Experiment 1: What was the mass of the crucible after the addition of copper? Choose the closest value. Select one: a. 35.000 g b. 45.000 g c. 100.518 g d. 88.000 g

b. 45.000 g

In the synthesis reaction, how many grams of magnesium were there in the crucible before heating? Select one: a. 6.2 g b. 5.0 g c. 4.1 g d. 8.3 g

b. 5.0 g

The amount of sodium chloride in the original mixture can be determined indirectly by subtracting the masses of ammonium chloride and sand from the initial sample mass of 10.000 g. When you perform this calculation, what is the mass of the sodium chloride? Select one: a. 6.710 g b. 0.950 g c. 2.620 g d. 14.250 g

a. 6.710 g

How many moles of anhydrous magnesium chloride remained in the crucible after heating? The molar mass of anhydrous magnesium chloride is 95.211 g/mol. Choose the closest answer. Select one: a. 0.02460 moles b. 1.015 moles c. 0.7026 moles d. 0.1475 moles

a. 0.02460 moles

Experiment 1: The molar mass of copper is 63.55 g/mol. How many moles of copper were reacted? Select one: a. 0.1574 mol b. 0.6724 mol c. 1.5421 mol d. 0.8822 mol

a. 0.1574 mol

The molar mass of oxygen is 16.00 g/mol. How many moles of oxygen are in copper oxide? Select one: a. 0.1574 mol b. 6.2824 mol c. 0.7824 mol d. 0.4785 mol

a. 0.1574 mol

Given the data you collected for the addition of 10.00 mL of ethanol to the graduated cylinder, what is the density of ethanol? Select one: a. 0.789 g/cm3 b. 1.58 g/mL c. 0.789 kg/cm3 d. 1.00 g/cm3

a. 0.789 g/cm3

Given the data you collected for the addition of 20.00 mL of water to the graduated cylinder, what is the density of water? Select one: a. 1.000 g/mL b. 2.000 g/cm3 c. 20.00 g/mL d. 1.000 kg/cm3

a. 1.000 g/mL

Given the data you collected for the addition of 30.00 mL of unknown liquid to the graduated cylinder, what is the density of the unknown liquid? Select one: a. 1.110 g/mL b. 0.1110 kg/cm3 c. 2.910 g/mL d. 11.10 g/mL

a. 1.110 g/mL

Experiment 1: How many grams of mass were lost during the heating process? Choose the closest answer. Select one: a. 1.804 g b. 91.196 g c. 2.315 g d. 3.196 g

a. 1.804 g

How much water did 15.0 g of iron displace? Select one: a. 1.9 mL b. 30.0 mL c. 0.6 mL d. 5.6 mL

a. 1.9 mL

What was the mass of the first 10.00 mL of water added? Select one: a. 10.000 g b. 54.000 g c. 20.000 g d. 64.000 g

a. 10.000 g

What was the mass of 20.00 mL of unknown liquid? Select one: a. 22.200 g b. 76.200 g c. 54.000 g d. 10.000 g

a. 22.200 g

What was the total volume of substances in the graduated cylinder after you added 30 g of iron? Select one: a. 23.8 mL b. 21.9 mL c. 50.0 mL d. 31.9 mL

a. 23.8 mL

How many grams of anhydrous copper(II) sulfate were in the crucible after heating? Choose the closest answer. Select one: a. 3.196 g b. 1.804 g c. 5.000 g d. 91.196 g

a. 3.196 g

How much water was displaced when you added 30 g of unknown metal? Select one: a. 4.2 mL b. 31.4 mL c. 0.7 mL d. 32.1 mL

a. 4.2 mL

What was the mass of the empty evaporating dish? Select one: a. 50.000 g b. 25.000 g c. 76.000 g d. 85.000 g

a. 50.000 g

What was the mass of the evaporating dish plus the powdered mixture? Select one: a. 73.741 g b. 127.000 g c. 10.000 g d. 98.000 g

a. 73.741 g

Calcium sulfate is a white solid found as two hydrates, a hemihydrate known as plaster of Paris and a dehydrate known as gypsum. The hemihydrate is a white solid as shown in the figure below. Given that the molar mass of the anhydrous calcium sulfate is 136.14 g/mol, the molar mass of the hemihydrate is 145.15 g/mol, and the molar mass of water is 18.015 g/mol, which formula gives the correct ratio for the hemihydrate? Select one: a. CaSO4⋅0.5H2O b. CaSO4⋅H2O c. CaSO4⋅7H2O d. CaSO4⋅2H2O

a. CaSO4⋅0.5H2O

Experiment 2: Which of the following represents the balanced chemical equation for this reaction? Select one: a. MgCl2⋅6H2O(s)⟶MgCl2(s)+6H2O(g) b. MgCl2⋅H2O(s)⟶MgCl2(s)+6H2O(g) c. MgCl2⋅5H2O(s)⟶MgCl2(s)+5H2O(g) d. MgCl2⋅6H2O(s)⟶6MgCl2(s)+H2O(g)

a. MgCl2⋅6H2O(s)⟶MgCl2(s)+6H2O(g)

Why did the temperature of the flask increase when hydrochloric acid and zinc were combined? Select one: a. The reaction was exothermic. b. The Bunsen burner heated the solution. c. The temperature probe was malfunctioning.

a. The reaction was exothermic.

Why was mass lost from the crucible during the reactions? Select one: a. The water of hydration was released as water vapor. b. Mass was converted to energy. c. The anhydrous salt decomposed into elements. d. The anhydrous salts absorbed water to form a hydrate.

a. The water of hydration was released as water vapor.

What is the main advantage of using the water displacement method to measure the volume of a metal versus using the length measurements? Select one: a. Water displacement can be used for irregularly shaped metals such as lumps. b. The water displacement method used less math. c. Water can hydrate the metal and keep its density constant. d. Water displacement can be used for metals that dissolve in water.

a. Water displacement can be used for irregularly shaped metals such as lumps.

Which liquid in the table below is most likely your unknown liquid? Substance Density (g/mL) ethyl acetate 0.897 ethylene glycol 1.110 glycerol 1.261 mercury 13.594 methanol 0.7928 Select one: a. ethylene glycol b. methanol c. ethyl acetate d. glycerol

a. ethylene glycol

What was the color of the magnesium chloride after heating? Select one: a. gray b. blue c. black d. green

a. gray

Experiment 1: What was the color of the copper before heating? Select one: a. red-orange b. white c. black d. blue-black

a. red-orange

Experiment 1: What was the mass of the copper oxide after heating? Choose the closest answer. Select one: a. 3.447 g b. 12.518 g c. 9.225 g d. 100.518 g

b. 12.518 g

Experiment 1: What is the molar ratio of copper to oxygen in the copper oxide formed? Select one: a. 3:2 b. 1:1 c. 2:1 d. 1:2

b. 1:1

What was the total volume of substances in the graduated cylinder after you added 15, 30, and 45 g of aluminum? Select one: a. 30.0 mL, 31.8 mL, 33.7 mL b. 25.5 mL, 31.1 mL, 36.7 mL c. 35.5 mL, 37.4 mL, 39.2 mL d. 31.8 mL, 35.5 mL, 37.4 mL

b. 25.5 mL, 31.1 mL, 36.7 mL

What was the mass of the empty beaker? Select one: a. 104.000 g b. 32.000 g c. 98.000 g d. 27.000 g

b. 32.000 g

What is the mass percent of NH4Cl in the original 10.000 g of powdered mixture? Choose the closest answer. The formula for mass percent calculations is given below: %m/m=mA/msample×100 Select one: a. 95.42% b. 5.29% c. 25.32% d. 48.62%

b. 5.29%

Given the data you collected for the volume of water displaced by 30 g of iron, what is the density of iron? Select one: a. 3.2 g/mL b. 7.9 g/cm3 c. 0.614 g/mL d. 2.7 g/mL

b. 7.9 g/cm3

What happened when NaOH was added to the copper(II) sulfate pentahydrate solution? Select one: a. Nothing happened. b. A blue precipitate formed. c. An orange precipitate formed. d. A green precipitate formed.

b. A blue precipitate formed

How can you tell that a reaction happened in the double-displacement reaction? Select one: a. A gas formed. b. A precipitate formed. c. A single product formed from two reactants. d. A color change occurred.

b. A precipitate formed.

How can you tell that the reaction from Experiment 1 is a synthesis reaction? Select one: a. A gas forms. b. A single product forms from two reactants. c. A precipitate forms. d. A color change occurs.

b. A single product forms from two reactants.

Experiment 1: Which of the following represents the balanced chemical equation for this reaction? Select one: a. CuSO4⋅H2O(s)⟶CuSO4(s)+H2O(g) b. CuSO4⋅5H2O(s)⟶CuSO4(s)+5H2O(g) c. CuSO4⋅2H2O(g)⟶CuSO4(s)+2H2O(g) d. CuSO4(g)+5H2O(g)⟶CuSO4⋅5H2O(s)

b. CuSO4⋅5H2O(s)⟶CuSO4(s)+5H2O(g)

Below is a graph of mass versus volume for iron. The density of iron is equal to the slope of the graph. Is the graph consistent with what you know about density? Select one: a. No. The density varies, therefore the volume is not directly proportional to the mass. b. Yes. The density is constant, therefore as the mass increases, the volume increases. c. No. The density is constant, therefore as the mass increases, the volume decreases. d. Yes. The density is constant, therefore as the mass increases, the volume decreases.

b. Yes. The density is constant, therefore as the mass increases, the volume increases.

Experiment 2: What was the identity of the precipitate that formed upon the addition of NaOH? Select one: a. copper sulfate b. copper hydroxide c. copper oxide d. copper metal

b. copper hydroxide

What was the color of the copper sulfate after heating? Select one: a. green b. light blue c. red d. black

b. light blue

The black powder formed at the end of the decomposition reaction is copper oxide (CuO). How many moles of copper oxide (MM = 79.545 g/mol) were produced (number of moles = mass (g) / molar mass (g/mol))? Choose the closest answer. Select one: a. 0.065 moles b. 0.052 moles c. 0.045 moles d. 0.032 moles

c. 0.045 moles

You measured the mass of three different volumes of unknown liquid. What was the total volume of unknown liquid used for each of the three mass measurements? Note: Depending on the actual amount of liquid dispensed in the lab, there is a range of possible answers. Pick the values that are closest to yours. Select one: a. 10.00 mL, 10.00 mL, 10.00 mL b. 61.80 mL, 69.80 mL, 77.68 mL c. 10.00 mL, 20.00 mL, 30.00 mL d. 10.00 g, 20.00 g, 30.00 g

c. 10.00 mL, 20.00 mL, 30.00 mL

Given the data you collected for the volume of water displaced by 30 g of aluminum, what volume of water do you expect 50.000 g of aluminum will displace? Select one: a. 5.4 mL b. 9.2 mL c. 18.5 mL d. 30.0 mL

c. 18.5 mL

Experiment 1: The copper changed to copper oxide upon heating. How many grams of oxygen were used in the reaction? Choose the closest answer. Select one: a. 1.042 g b. 3.664 g c. 2.518 g d. 7.992 g

c. 2.518 g

Experiment 2: How many grams of water were lost during the heating process? Choose the closest answer. Select one: a. 1.000 g b. 0.663 g c. 2.658 g d. 4.148 g

c. 2.658 g

Given the data you collected for the volume of water displaced by 45 g of aluminum, what is the density of aluminum? Select one: a. 0.6 g/mL b. 13.5 g/mL c. 2.7 g/cm3 d. 3.3 g/cm3

c. 2.7 g/cm3

What was the original volume of water before adding iron? Select one: a. 84.0 mL b. 30.0 mL c. 20.0 mL d. 30.6 mL

c. 20.0 mL

What was the total volume of substances in the graduated cylinder after the addition of 15.000 g of unknown metal? Select one: a. 2.1 mL b. 30.7 mL c. 22.1 mL d. 20.0 mL

c. 22.1 mL

Which of the following represents the balanced equation for the synthesis reaction of Mg pictured below? (Picture of Lava) Select one: a. Mg(s)⟶MgO(s)+O2(g) b. Mg(s)+O2(g)⟶MgO(s) c. 2Mg(s)+O2(g)⟶2MgO(s) d. Mg(s)+O(g)⟶MgO(s)

c. 2Mg(s)+O2(g)⟶2MgO(s)

In the decomposition reaction, how many grams of product were in the crucible after heating? Remember to subtract the mass of the crucible. Choose the closest answer. Select one: a. 5.0 g b. 4.1 g c. 3.6 g d. 1.4 g

c. 3.6 g

How many grams of copper sulfate hydrate were added to the crucible before heating? Note: Depending on the amount dispensed from the container, there is a range of possible masses. Pick the answer that is closest to yours. Select one: a. 3.000 g b. 7.000 g c. 5.000 g d. 9.000 g

c. 5.000 g

Given the data you collected for the volume of water displaced by 25.000 g of unknown metal, what is the density of the unknown metal? Choose the value closest to your result. Select one: a. 0.74 g/mL b. 7.3 kg/cm3 c. 7.3 g/cm3 d. 2.7 g/cm3

c. 7.3 g/cm3

What was the mass of the evaporating dish and the remaining contents after the sublimation of NH4Cl? Choose the closest answer. Select one: a. 125.321 g b. 86.000 g c. 72.485 g d. 95.655 g

c. 72.485 g

You measured the mass of three different volumes of water. What was the total mass of the graduated cylinder and the water for the three measurements? Choose the masses that are closest to the observed values. Select one: a. 85.000 g, 105.000 g, 125.000 g b. 75.000 g, 85.000 g, 95.000 g c. 85.000 g, 95.000 g, 105.000 g d. 10.000 g, 20.000 g, 30.000 g

c. 85.000 g, 95.000 g, 105.000 g

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? Select one: a. Copper argon would form, increasing the mass of the product. b. The copper oxide yield would be higher. c. Copper oxide would not form and the mass would not change. d. The copper oxide yield would be lower.

c. Copper oxide would not form and the mass would not change.

Why is density referred to as a characteristic property of matter? Select one: a. Only certain types of matter have density. b. Density is a property specific to solid substances. c. Density can be used to identify the type of matter. d. Density can be used to identify the state of the matter.

c. Density can be used to identify the type of matter.

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 Select one: a. LiN2 b. LiN3 c. Li3N d. LiN

c. Li3N

Why do you think you were required to take three measurements for each experiment instead of just one? Select one: a. You need a list of three data points to plot data. b. It takes three tries to accurately perform an experiment. c. Taking three measurements minimizes the risk of experimental error. d. Taking three measurements gives you more practice in the laboratory.

c. Taking three measurements minimizes the risk of experimental error.

In the synthesis reaction, what was the change in mass of the contents in the crucible after heating compared to the mass before heating? Choose the closest answer. Select one: a. The mass decreased by 8.291 g. b. The mass decreased by 3.291 g. c. The mass increased by 3.291 g. d. The mass increased by 8.291 g.

c. The mass increased by 3.291 g.

In the single-displacement reaction, what happened to the temperature and pressure immediately after adding the zinc? Select one: a. The pressure decreased, and the temperature increased. b. The pressure increased, and the temperature decreased. c. The pressure increased, and the temperature increased. d. The pressure decreased, and the temperature decreased.

c. The pressure increased, and the temperature increased.

In the decomposition reaction, mass was lost. Where did the mass go? Select one: a. Water vapor and carbon dioxide gas were absorbed from the atmosphere. b. This represents a violation of the law of conservation of matter. c. Water vapor and carbon dioxide gas were released into the atmosphere. d. The mass was converted to energy by the flame.

c. Water vapor and carbon dioxide gas were released into the atmosphere.

How many moles of anhydrous copper(II) sulfate remained in the crucible after heating? The molar mass of anhydrous copper(II) sulfate is 159.609 g/mol. Choose the closest answer. Select one: a. 0.1001 moles b. 0.0010 moles c. 1.0005 moles d. 0.02002 moles

d. 0.02002 moles

Experiment 1: How many moles of water were lost during the heating? The molar mass of water is 18.015 g/mol. Choose the closest answer. Select one: a. 1.0010 moles b. 0.3003 moles c. 0.2002 moles d. 0.1001 moles

d. 0.1001 moles

How many moles of copper(II) sulfate pentahydrate were used in the reaction? The molar mass of copper(II) sulfate pentahydrate is 249.68 g/mol. For best accuracy, use the mass measured with the balance during the experiment. Choose the closest answer. Select one: a. 0.04005 moles b. 0.3404 moles c. 0.3605 moles d. 0.1001 moles

d. 0.1001 moles

In the synthesis reaction, the white powder produced is magnesium oxide (MgO, MM = 40.3 g/mol). How many moles of magnesium oxide were formed (number of moles = mass (g) / molar mass (g/mol))? Choose the closest answer. Select one: a. 0.31 moles b. 0.41 moles c. 0.11 moles d. 0.21 moles

d. 0.21 moles

In the decomposition reaction, 1 mole of water (MW = 18.015 g/mol) was produced for every mole of CuO (MW = 79.545 g/mol) produced. If 3.6 g of CuO was produced during the reaction, how many grams of water were released as water vapor? (number of moles = mass (g) / molar mass (g/mol)). Choose the closest answer. Select one: a. 3.98 g b. 1.80 g c. 0.92 g d. 0.82 g

d. 0.82 g

How many grams of anhydrous magnesium chloride were in the crucible after heating? Choose the closest answer. Select one: a. 3.141 g b. 0.852 g c. 1.196 g d. 2.342 g

d. 2.342 g

How many grams of copper(II) sulfate pentahydrate were added to the beaker? Note: The amount of materials dispensed can vary. Choose the answer that is closest to yours. Select one: a. 2.000 g b. 10.000 g c. 1.000 g d. 25.000 g

d. 25.000 g

What is the mass percent of NaCl in the original 10.000 g of powdered mixture? Choose the closest answer. The formula for mass percent calculations is given below: %m/m=mA/msample×100 Select one: a. 95.40% b. 78.62% c. 55.30% d. 28.26%

d. 28.26%

What was the mass of the beaker with the SiO2 after decanting? Choose the closest answer. Select one: a. 108.237 g b. 86.322 g c. 25.158 g d. 47.775 g

d. 47.775 g

In the decomposition reaction, how many grams of copper carbonate hydroxide were in the crucible before heating? Select one: a. 8.3 g b. 6.2 g c. 4.1 g d. 5.0 g

d. 5.0 g

What was the mass of the sodium chloride after evaporating the water? Select one: a. 25.355 g b. 8.987 g c. 5.456 g d. 6.710 g

d. 6.710 g

What is the mass percent of SiO2 in the original 10.000 g of powdered mixture? Choose the closest answer. The formula for mass percent calculations is given here: %m/m=mA/msample×100 Select one: a. 95.48% b. 48.68% c. 10.82% d. 66.45%

d. 66.45%

How many mL of gas were produced in the single-displacement reaction? Choose the closest answer. Select one: a. 100.7 L b. 86.14 L c. 123.6 mL d. 73.6 mL

d. 73.6 mL

In the synthesis reaction, how many grams of product remained in the crucible after heating? Remember to subtract out the mass of the crucible. Choose the closest answer. Select one: a. 6.8 g b. 4.1 g c. 5.0 g d. 8.3 g

d. 8.3 g

You measured the mass of three different volumes of unknown liquid. What was the total mass of the graduated cylinder and the unknown liquid for the three measurements? Choose the masses that are closest to the observed values. Select one: a. 75.000 g, 86.100 g, 97.200 g b. 10.000 g, 20.000 g, 30.000 g c. 75.000 g, 85.000 g, 95.300 g d. 86.100 g, 97.200 g, 108.300 g

d. 86.100 g, 97.200 g, 108.300 g

What was the initial mass of the graduated cylinder with the 20 mL of water? Select one: a. 30.000 g b. 54.000 g c. 109.000 g d. 95.000 g

d. 95.000 g

What is the empirical formula of copper oxide based on your results in Experiment 1? Select one: a. Cu2O3 b. CuO2 c. Cu2O d. CuO

d. CuO

In the decomposition reaction, what happened to the mass of the contents of the crucible after heating? Select one: a. It was not determined. b. It was unchanged. c. It increased. d. It decreased.

d. It decreased.

In the double-displacement reaction, what happened when the contents of the two flasks were mixed? Select one: a. The solution turned green, and a black precipitate formed. b. The solution turned green, and a black precipitate formed. c. The solution turned clear, and a black precipitate formed. d. The solution turned clear, and a green precipitate formed.

d. The solution turned clear, and a green precipitate formed

In the decomposition reaction, what happened to the contents of the crucible as they heated? Select one: a. They turned from red to green. b. They turned from green to red. c. They turned from black to green. d. They turned from green to black.

d. They turned from green to black.