Chemistry Exam

A student studies a burning candle. Choose the statement he wrote in his notes that is an interpretation.

"The candle produces carbon dioxide as it burns."

After completing the precipitation experiment, a student records the following statements: (I) After mixing the solutions a cloudy precipitate formed. (II) The filtrate was colorless and clear. (III) The precipitate formed when low soluble ions came in contact in solution. (IV) There was a large experimental error probably due to the fact the precipitate was still damp when weighed. Which are observations and which are interpretations?

(I) and (II) are observations; (III) and (IV) are interpretations

A solution of lead(II) nitrate is added to a solution of lithium sulfide, producing lead(II) sulfide and lithium nitrate. The states of matter for these four substances would be, respectively

(aq), (aq), (s), (aq)

4.867 ms= ?s

0.004867 s

The quantity of matter in a sample of sand is correctly written as

0.007 62 mol

How many moles of BaCl2 forms when 1.50 g HCl reacts with excess barium hydroxide

0.0206 mol

23.6 mg= ?g

0.0236 g

Using the balanced equation below, calculate the number of moles of calcium hydroxide produced when 1.20 g of calcium metal is placed in water. Ca + 2 H₂O→ Ca(OH)₂ + H₂

0.0299 mol

Strontium phosphate can be precipitated from potassium phosphate and strontium nitrate by the reaction, 3 Sr(NO₃)₂(aq) + 2 K₃PO₄(aq)→ Sr₃(PO₄)₂(s) + 6 KNO₃(aq) The quantity of strontium nitrate required to make 4.53 g of precipitate is

0.0300 mol

Limewater, Ca(OH)2(aq), may be used to test for carbon dioxide gas according to the balanced equation, Ca(OH)₂(aq) + CO₂(g) → CaCO₃(s) + H₂O(l). The quantity of carbon dioxide required to precipitate out 6.20 g of calcium carbonate is

0.0619 mol

The quantity of AlPO₄ required for a complete reaction is

0.0667 mol

When a potassium metal reacts with water, hydrogen gas and a hydroxide are produced: 2 K(s) + 2 HOH(l)→ H₂(g) + 2 KOH(aq) The quantity of hydrogen gas produced by reacting 0.30 mol of potassium metal is

0.15 mol

__HCl(aq) +__Ca(OH)₂(s)→ ? + ? The quantity of hydrochloric acid required to react with 0.240 mol of calcium hydroxide in the above equation is

0.480 mol

How many moles of rust {iron(III) oxide} can form from 1.05 mol of iron?

0.525 mol

0.01 g

1

__NaOH(aq) + __Al(NO₃)₃(aq)→ __Al(OH)₃(s) + __NaNO₃(aq) The coefficient for Al(NO₃)₃(aq) would be

1

To the correct number of significant digits, 0.1 L is equal to

1 x 10² mL

The answer to the following computation is 1.80 kg/122.15 g/mol = x/84.01 L/cm²

1.24 kL∙mol/cm²

In an airship similar to the Goodyear balloon used for reporting sports events, 1.80 GL of hydrogen gas catches fire and burns. What mass of water is formed by this reaction? (NOTE: helium is now used to prevent such a disaster.)

1.45 Gg

___ Al + ___Zn(CH₃COO)₂→ ___ Zn + ___ Al(CH₃COO)₃

10

__C₃H₈(g) + __O₂(g) → __CO₂(g) + __H₂O(g) The quantity of O₂(g) required to react with 2.0 mol of C₃H₈(g) in the unbalanced equation above is

10.0 mol

The volume of a sample of silver, determined by water displacement, was found to be 0.963 mL. A chemistry handbook gives the density of silver as 10.50 g/mL. If m = v∙d, the mass of the silver sample, calculated to the correct number of significant digits, is

10.1 g

Potassium hydroxide will react with ferric chloride to produce ferric hydroxide and potassium chloride. The mass of ferric hydroxide produced from 3.00 mol of potassium hydroxide would be

107 g

16.0 mL - 5 mL

11 mL

If the mass of chemical and beaker is 158.35 g and the mass of the beaker alone is 27.6 g, then the amount of chemical present is

130.8 g

The molar mass of sodium sulfate is

142.05 g/mol

Calculate the molar mass of ammonium phosphate.

149.12 g/mol

A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 1.000 atm if pHe = 607.5 mm Hg and pCO₂ = 2.5 mm Hg?

150 mm Hg

Calculate the molar mass of water

18.02 g/mol

CaI₂ + Cu₂SO₄→ If the equation above were completed, the number of low solubility compounds in the equation would be

2

Use this information to answer questions #117 and 118 137 g of Mg(OH)² were reacted according to the equation: __Mg(OH)₂ + __HBr→ __HOH + __MgBr₂ The number of moles of Mg(OH)₂ reacted was

2.35 mol

25.2 L expressed in milliliters, to the correct number of significant digits is

2.52 x 10⁴ mL

What mass of copper(II) sulfate pentahydrate is needed to give 0.0800 mol?

20.0 g

Use the equation below (unbalanced) to calculate the volume of sulfur trioxide that forms when 200 L of sulfur dioxide is further oxidized. ? SO₂ + ? O₂→ ? SO₃

200 L

What volume of nitrogen is required to form 18.2 mol nitrogen dioxide at STP from their elements?

204 L

If the mass of X used was 10.0 g. the mass of Y₂Z used was 18.0g, and the mass of X2Z3 produced was 7.0 g, how much of Y was also formed?

21.0 g

A piece of copper is placed in a beaker containing a silver nitrate solution. If the mass of copper lost is 6.36 g, what mass of silver metal would form? (HINT: a copper(II) compound is one product!)

21.6 g

A formula unit contains 3 ions of barium, 2 atoms of phosphorus and 8 atoms of oxygen. The mass of 0.359 mol of these formula units is

216 g

What volume of carbon dioxide can form at STP if 160 g of oxygen is used to burn excess carbon monoxide?

224 L

The symbol Co CANNOT represent

27 g of cobalt.

Use these balanced equations to answer questions #38 to 40. 1. CH₄(g) + 2 O₂(g)→ CO₂ + 2 H₂O + heat and light 2. Zn(s) + H₂SO₄(aq)→ H₂ + ZnSO₄ + heat 3. Co(NO₃)₂(aq) + 2 KOH(aq)→ Co(OH)₂ + 2 KNO₃ + heat 4. H₂(g) + Cl₂(g)→ 2 HCl + heat A precipitate is most likely formed in reaction

3

P₄O₁₀(s) + 6 H₂O(l)→4 H₄PO₄(l) + heat The statement about the above equation that is FALSE is

3 mol of substance has been converted to energy.

Barium acetate + aluminum phosphate→ barium ? + aluminum ?

3, 2, 1, 2

What mass of carbon dioxide forms when 1.00 g of coal (assume pure carbon) burns

3.66 g

A compound ZX², has a molar mass of 79.00 g/mol. The atomic molar mass of Z is 19.00 g/mol. The atomic molar mass of X is

30.00 g/mol

If 152 g of ferrous sulfate combines with 2.00 mol of copper(I) hydroxide the total mass of all products formed is

313 g

One mole of atoms is contained in

32.07 g of S₈

Calculate the molar mass of table sugar.

342.34 g/mol

3.5 km= ?m

3500 m

The molar mass of tin(IV) nitrate is

366.73 g/mol

Potassium chlorate, KClO₃(s), will decompose when heated to produce potassium chloride, KCl(s), and oxygen, O₂(g). The mass of O₂(g) produced when 37.3 g of KCl(s) is produced would be

37.3 g

9.000 kg

4

__ TiCl₄→ ___ Ti + ___ Cl₂

4

0.015 mol/0.125 L

.12 mol/L

15 cm= ?m

.15 m

425 mL= ?L

.425 L

A bottle of CCl₄ contains a total of "X" molecules. The best apparatus that one could use to determine "X" would be a

Balance

If the percent oxygen in Moscow were compared to the percent oxygen in St. Louis, what would be observed?

Both cities have nearly the same percent oxygen.

For the next nine questions select the letter of the PHYSICAL STATE(S) below which best fill the blanks. Use the following: A. (s) B. (l) C. (g) D. (aq) E. could be (s), (l), or (g): only experience can tell for sure. Any element, whose symbol is red on the periodic table is usually ____ in equations.

C

Water is found as _____ in combustion reactions.

C

Boyle's law

P₁V₁ = P₂V₂

Combined

P₁V₁/T₁ = P₂V₂/T₂

Use the following balanced equations to answer the following question. 1. C(s) + O₂(g)→ CO₂(g) + heat 2. 2 C₂H₆(g) + 7 O₂(g)→ 4 CO₂(g) + 6 H₂O(g) + heat and light 3. Mg(s) + 2 HCl(aq)→ H₂(g) + MgCl₂(aq) + heat 4. Fe(NO₃)₃(aq) + 3 NaOH(aq)→ Fe(OH)₃(s) + 3 NaNO₃(aq) + heat Which of the reactions is CORRECTLY identified as to reaction type?

Reaction 4 is double replacement

Which one of the reactions is CORRECTLY identified as to reaction type?

Reaction 4 is simple composition

Use this data to answer questions #146 to 148. 116 g of Sc(NO₃)₃(aq) reacts with Mg(OH)²(s). __Mg(OH)₂(s) + __Sc(NO₃)₃(aq)→ __Mg(NO₃)₂(aq) + ______

Sc(OH)₃(s)

Which of the following is an example of a single replacement reaction?

Sn(g) + FeSO₄(aq) →Fe(s) + SnSO₄(aq).

The sentence below that contains NO errors in SI usage is

Steven drives at 100 km/h.

Which one of the following represents a double replacement reaction?

Sulfuric acid + potassium hydroxide→water + potassium sulfate

Which statement below does NOT express a valid reason for us to use the SI system?

The United States is a "metric" country

Which of the sentences given below has exactly ONE error in SI usage?

The beaker contained 40.3 ml of water

For the precipitation experiment in this unit RINSING played an important role. Select the FALSE statement about rinsing.

The filter paper must be rinsed before use to avoid contamination.

The volume of a gas is doubled while the temperature is held constant. What happens to the pressure of the gas?

The gas pressure is decreased to half of the original amount.

Which is a TRUE statement about the movement of gas molecules

The lighter molecules move faster than the heavy molecules.

Which situation below does NOT involve the principle of stoichiometry

The number of centimeters in a meter is 100.

Select the correct statement regarding stoichiometric calculations.

The numerical relationship between what is "asked" and what is "given" must be known.

Which of the following would most likely explain a LARGE experimental error in a precipitation reaction similar to the one done in this unit?

The precipitate and filter paper was not completely dry when weighed.

In the following reaction find the missing reactant from the choices below. Na₂CO₃ + _____ → H₂CO₃ + Na₃PO₄

H₃PO4

A student measures the following quantities. Which one(s) is/are not shown with the most appropriate unit? I. length of a pencil (cm) II. amount of molecules in a handful of sand (mol) III. volume of a teacup (mL) IV. mass of a twenty five cent piece (kg) V. temperature of the human body (°C)

IV only

Dalton's law

P total = P₁+P₂+P₃...

Ideal Gas Law

P x V = n x R x T

Ideal Gas Law

PV=nRT (R=8.314 kPal mol⁻¹∙K⁻¹

In reactions, hydrocarbons are ____.

E

The physical states of molecular compounds in simple composition and decomposition reactions are usually ____.

E

Avogadro's Hypothesis

Equal volumes of a gas at the same temperature and pressure contain the same number of molecules.

Which atoms are not balanced?

Y

Charles' law

V₁/T₁ = V₂/T₂

Avrogado's law

V₁/n₁ = V₂/n₂

Which of the following procedures for operating a balance will affect the accuracy of the measurement?

putting the balance at zero before use.

Aluminum reacts with oxygen in the air to form a protective coating. This reaction would be an example of

simple composition

C(s) + O₂(g)→CO₂(g). This reaction is an example of a

simple composition reaction.

Consider the following reaction and answer the next four questions below: 2 X( ) + 3 Y₂Z( ) → X₂Z₃( ) + 3 Y( ) What type of reaction is it?

single replacement

Pure zinc can be used to "get the lead out" of a solution of lead(II) acetate. This reaction is an example of

single replacement

C₁₂H₂₂O₁₁ (s)

sucrose

If the absolute temperature of the gas in a balloon decreases,

the average kinetic energy of the gas decreases proportionately.

Increasing the volume of a given amount of gas at constant temperature causes the pressure to decrease because

the molecules are striking a larger area with the same force.

When the volume of a gas is decreased, with the temperature remaining constant, the pressure of the gas increases. This is because

the particles are hitting the walls of the container more frequently.

As a helium balloon is allowed to rise in the atmosphere,

the temperature falls and the pressure falls.

The pressure exerted by a gas in a closed container depends on the number of collisions between gas molecules and the

walls of the container.

H₂O (l)

water

NH₃ (g)

ammonia

What is the most likely physical state of Y₂Z

aqueous

Precipitates generally appear

as products in replacement reactions

A barium hydroxide solution reacts with sulfuric acid to produce barium sulfate and water. Which of the compounds in the balanced equation would be a solid species?

barium sulfate

The process that does NOT involve a chemical reaction is

boiling water

If a scuba diver is not careful when ascending from great depths of water, he may develop decompression sickness. How might this be avoided?

by ascending slowly

The complete combustion of a hydrocarbon yields

carbon dioxide and water vapor.

The reaction represented by the equation H₂CO₃(aq)→ H₂O(g) + CO₂(g) is

decomposition

A closed, flexible container (e.g., a balloon) maintains a constant pressure and number of moles of gas (i.e., it does not leak). If the volume of the container is decreased, the temperature will

decrease.

When a gas inside a syringe is expanded without a change in temperature, the gas pressure will

decrease.

Temp ↑ Kinetic Energy ↑

direct

Temp ↑ Pressure ↑

direct

Volume ↑ Temp ↑

direct

According to the Kinetic Molecular Theory, the average kinetic energy (AKE) of the molecules in an ideal gas is

directly proportional to the temperature, in kelvins, of the molecules.

A mole can be compared to a dozen or gross in the sense that

each represents a defined number of things.

The reaction for a furnace burning natural gas to heat a house is CH₄(g) + 2 O₂(g)→CO₂(g) + 2 H₂O(g) + energy This balanced equation illustrates all of the following EXCEPT that

energy can be created (or destroyed) in chemical reactions

C₂H₅OH (l)

ethanol

C₃H₈ + O₂→ CO₂ + H₂O In the above combustion reaction, the physical state of H₂O would be

gas

The unit that does NOT belong in the list below is

gram.

H₂O₂ (l)

hydrogen peroxide

H₂S (g)

hydrogen sulfide

Which of the following molecules would move the fastest if each atom had the same temperature?

hydrogen, H₂

When a gas is compressed the temperature will

increase.

When the temperature goes up, the velocity of gas molecules

increases.

12 in/ft

infinite

Determine the number of significant digits in each of the following. 60 min/h

infinite

Temp ↓ Density ↑

inverse

It is impossible to ? an ideal gas.

liquefy

Under which conditions would a gas be most likely to change to a liquid?

low temperature and high pressure

Five quantities are measured. Select the choice below that correctly shows the best units for the measurements. Keep the same order! I. the width of a classroom II. the mass of a sack of potatoes III. the thickness of your fingernail IV. the volume of a small aquarium V. the length of a long walk

m, kg, mm, L, km

CH₄ (g)

methane

CH₃OH (l)

methanol

The mole is a unit which expresses a

number of things.

Which one of the following represents a double replacement reaction?

phosphoric acid + barium hydroxide→ water + barium phosphate

Which statement best explains why the volume of a gas decreases when the temperature decreases?

As molecules cool, they move slower and are closer together.

Dalton's Law

At constant volume and temperature, the total pressure exerted by a mixture of gases is equal to the sum of the partial pressures.

Bromine and mercury are two elements that are generally found as ____.

B

Water is found as _____ in replacement reactions.

B

If kinetic energy is added to a sample of gas in a rigid container (a steel tank), which of the following takes place?

All of the above occur.

The compound that would NOT dissolve significantly in water would be

Al₂(CO₃)₃

(75 mol)(59.05 km/yr)

44 mol∙km/yr

If you predict that 1.20 mol of calcium oxide (lime) should be used in a chemical reaction, then the mass of calcium oxide reacted should be

67.3 g

2 A + B→ 4 C In the above reaction 3.00 g of A will produce 10.00 g of C. The mass of B used would be

7.00 g

The molar mass of chlorine gas is

70.90 g/mol

Which number below would NOT be considered an "exact" number?

8 minutes

Using the balanced equation below, calculate the number of moles of sodium metal consumed while 4.12 mol chlorine reacts with the metal. 2 Na + Cl₂→ 2 NaCl

8.24 mol

Using the balanced equation below to calculate the number of moles of aluminum consumed when 4.20 kg aluminum oxide is produced. 4 Al +3 O₂→ 2 Al₂O₃

82.4 mol

9.0 km= ?mm

9.0 ∙ 10⁶ mm

When 4.20 mol of oxygen is placed in a balloon, to what volume does the balloon expand?

94.1 L

0.0951 L = ?mL

95.1 mL

12.59 cm³ x 7.87 g/cm³

99.1 g

If a sample of a compound contains 1.36 mol of nitrogen atoms and 2.72 mol of oxygen atoms, the formula for the compound could be

NO₂

Which of the following statements about a chemical reaction is FALSE?

New atoms are created

Which of the following statements about a chemical reaction is FALSE?

New atoms are created.

The formula of the compound is

N₂O₃

The balanced equation for the reaction of gasoline, C₈H₁₈(l), with oxygen gas to produce carbon dioxide gas and water vapor is

2 C₈H₁₈(l) + 25 O₂(g)→16 CO₂(g) + 18 H₂O(g)

Which represents two molecules of hydrogen gas

2 H₂

Perform the calculation, 0.022 mol ∙ 184.5 g/mol, to the correct number of significant digits.

4.1 g

0.000 042 6 mol expressed in proper scientific notation format is

4.26 x 10⁻⁵ mol

(3.00 ∙ 10⁸ m/s) / (6.441 ∙ 10⁻⁷ m)

4.66∙10¹⁴/s

The following list of measurements, when rounded off to 3 significant digits, is (keep same order!) 4.863 11.052 0.03996 1423.06 118.48

4.86, 11.1, 0.0400, 1.42 x 103, 118

5.09 - 123.7 mg

4.97 g

Calculate the molar mass of NaOH.

40.00 g/mol

When 60.0 L of bromine vapor condenses at STP, what mass of liquid bromine is found?

428 g

In the reaction of carbon with oxygen to produce carbon dioxide, the mass of gas produced depends directly on the mass of carbon burned because

Carbon and oxygen atoms combine in a fixed ratio.

What factor is responsible for the pressure of gases in their container

Choices A, B and C are all involved in gas pressure.

At high temperatures and low pressures a real gas behaves very nearly like an ideal gas. What choice best explains why this is true?

Choices A, B, and C are all correct.

Which of the following is a hydrocarbon

C₂H₆

The products of the following reaction are CrI₃ + NaOH→ _____ + _____

Cr(OH)₃ and NaI

Boyle's Law

For a given mass of gas at a constant temperature, the volume of the gas varies inversely with pressure.

Which of the following is not a postulate of the kinetic molecular theory

Gas molecules all have the same kinetic energy

Which one of the following does NOT represent a chemical reaction?

Heat is absorbed to melt snow.

Which one of the following does NOT represent a chemical reaction?

Heat is used to melt solder when soldering water pipes.

Which answer best explains why a helium-filled balloon shrinks faster than an oxygen-filled balloon?

Helium molecules are smaller and lighter than oxygen molecules. Therefore, they more easily escape through the holes between the latex molecules making up the balloon.

The product in the reaction between lithium and nitrogen is

Li₃N(s)

According to the Kinetic Molecular Theory, which statement best explains why the percent oxygen in Chicago, Illinois is nearly the same as the percent oxygen in Anchorage, Alaska?

Molecules are in constant motion and naturally spread out.

Assuming that each of the following answers represents a product of double replacement reaction of two solutions, which would form as a solid precipitate?

ZnS

The reaction that does NOT produce a gas is reaction

#3

A base (hydroxide solution) spill or burn should be neutralized immediately with vinegar. For example: __Ba(OH)₂(aq) + __CH₃COOH(aq) → __HOH(l) + __Ba(CH₃COO)₂(aq) The quantity of acetic acid required to neutralize 3.4 g of barium hydroxide is

0.040 mol

For the reaction 2 NO²(g)→ N²(g) + 2 O₂(g), the quantity of N₂(g) produced when 0.20 mol of NO₂(g) is decomposed is

0.10 mol

CuBr₂(aq) + Ag₂SO₄(aq) → 2 AgBr(s) + CuSO₄(aq) The TRUE statement about the above reaction is

0.10 mol of CuBr₂ reacts with 0.10 mol of Ag₂SO₄.

2 Cr(NO₃)₃(aq) + 3 Ca(OH)₂(s)→ 2 Cr(OH)₃(s) + 3 Ca(NO₃)₂(aq) The TRUE statement about the above reaction is

0.20 mol of Na₃PO₄(s) reacts with 0.30 mol of CaO(s).

The measurement that shows three significant digits is

0.204 g

__HCl(g) + __O₂(g) → __H₂O(g) + __Cl₂(g) The quantity of O₂(g) required to react with 2.00 mol of HCl(g) in the above reaction is

0.25 mol

A liter of liquid propane is about 14 mol. What volume of propane gas results when a liter of liquid propane evaporates at STP?

0.31 kL

An experiment calls for 0.00200 mol KMnO₄. What mass must be obtained?

0.316 g

How many moles are represented by 16.0 g of CO₂

0.364 mol

Slaked lime, Ca(OH)₂, reacts with trisodium phosphate or TSP (the commercial name for Na₃PO₄) to produce rock phosphorus and lye: __Ca(OH)₂ + __ Na₃PO₄ __ Ca₃(PO₄)₂ + __NaOH The quantity of sodium phosphate required to produce 48 g of sodium hydroxide is

0.4 mol

Na₂CO₃(aq) + 2 HCl(aq) → 2 NaCl(aq) + H₂CO₃(aq) The TRUE statement about the reaction above is

0.4 mol of HCl(aq) reacts with 0.2 mol of Na₂CO₃(aq).

Balance the equation below then find the mass of calcium hydroxide precipitate that forms when 1.00 g calcium nitrate reacts as shown. ? Ca(NO₃)₂ + ? Ba(OH)₂→ ? Ba(NO₃)₂ + ? Ca(OH)₂

0.452 g

In an experiment, the total mass of all reactants combined was 4.20 g. There were three products that formed. Two of the products' masses added up to 3.65 g. What was the mass of the third product also formed?

0.55 g

The coefficients of the following balanced equation are respectively ___ H₃PO₄+ ___ Al(OH)₃→ ___ HOH + ___ AlPO₄

1, 1, 3, 1

Lead(IV) sulfide + calcium hydroxide→lead(IV) hydroxide + calcium sulfide When the above equation is balanced the coefficients are

1, 2, 1, 2

When the following equation is balanced, the coefficients are lead(IV) sulfide + calcium hydroxide → lead(IV) hydroxide + calcium sulfide

1, 2, 1, 2

When the equation, __Al₂(CO₃)₃(s) + __CaBr₂(s)→ __CaCO₃(s) + __AlBr₃(aq) is balanced, the coefficients are

1, 3, 3, 2

When the following equation is balanced, the coefficients are ___ Ca₃(PO₄)₂ + ___ KCl → ___ K₃PO₄ + ___ CaCl₂

1, 6, 2, 3

Consider the following unbalanced equation: __S₈(s) + __O₂(g) __SO₂(g). When the above equation is balanced, the coefficients from left to right are

1, 8→8

A 4.00 L sample of gas is at 25C and 1.00 atm pressure. What will be the volume if the pressure is increased to 4.00 atm and the temperature remains constant?

1.00 L

.Expressed in scientific notation and to the correct number of significant digits, the quotient of (1.5 ∙ 0.400/ 400) is

1.5 x 10⁻³ g

The equation below has not been balanced. Use it to find the number of liters of oxygen consumed when 120 kL of gasoline vapor burns in air. ? C₈H₁₈ + ? O₂→ ? CO₂ + ? H₂O

1.50 ML

Balance the equation below then determine the mass of copper(II) oxide that forms when 1.24 g of copper roofing material oxidizes. ? Cu + ? O₂→? CuO

1.55g

In the reaction 2 A + B→ C + 3 D, if 4.7 g of A is completely reacted with 3.1 g of B, 6.2 g of D are produced. The mass of C that is also produced is

1.6 g

K₂S(aq) + CuBr₂(aq) → CuS(s) + 2 KBr(aq) When 4.76 g of potassium bromide is produced, the mass of copper(II) sulfide precipitate formed in the above reaction is

1.91 g

What mass of sulfur dioxide gas is produced in a natural gas well that yields 680 kL of SO₂ per day?

1.94 t (Mg)

Complete the following. Express the answer to the correct number of significant digits. 6.7g + 0.03 g + 3.89 g

10.6 g

The mass of Mg(NO₃)₂(aq) that will result when the 116 g of Sc(NO₃)₃(aq) completely reacts is

112 g

Use the given balanced equation to find the volume of oxygen at STP needed to burn 1.00 kmol of propane. C₃H₈ + 5 O₂→ 3 CO₂ + 4 H₂O

112 kL

Perform the following metric conversions keeping the same number of significant digits. 12 cm³ =

12 mL

Which list below shows only numbers containing 3 significant digits?

12.0, 101, 8.20 x 104, 0.0104

N₂(g) + 3 H₂(g)→2 NH₃(g) The mass of hydrogen that will react with 2.00 mol of nitrogen in the reaction above is

12.1 g

Using the following balanced equation to determine the volume of hydrogen produced when 10.0 g water is electrolyzed using Hoffman's apparatus. 2 H₂O→ 2 H₂ + O₂

12.4 L

Air is approximately 80% nitrogen and 20% oxygen. How much does a 10.0 L sample of air at STP weigh?

12.9g

When 100 g of water evaporates, what volume of vapor forms

124L

If A is an element with a molar mass of 40.00 g/mol, and B is another element with a molar mass of 17.50 g/mol, then the molar mass of A₂B₃ is

132.50 g/mol

Assuming that the chemical formula for sand is SiO2, the number of moles of SiO2 in a 8.00 kg sample of sand is

133 mol

If 0.250 mol of iron are required for an experiment, then the mass of iron required is

14.0 g

Which one of the following is NOT equivalent to the rest?

16.0 g of O2₂ molecules.

The amount of material measured with a graduated cylinder would BEST be recorded as

16.5 mL

The mass of 0.25 mol of a compound with the molecular formula AB₃ is 17 g. If the molar mass of element A is 11 g/mol, the molar mass of element B is

19 g/mol

Using the equation below, calculate the volume of product that results at STP when 28.4 mg of sulfur burns. S₂ + 8 O₂→8 SO₂

19.8 mL

Which one of the following equations is CORRECTLY balanced?

2 H₂O₂(l)→2 H₂O(l) + O₂(g)

Which of the following equations is CORRECTLY balanced?

2 H₂O₂→ 2 H₂O + O₂

Potassium hydroxide and barium chloride react to produce barium hydroxide and potassium chloride. The balanced equation for this reaction is

2 KOH(aq) + BaCl₂(aq)→ Ba(OH)₂(aq) + 2 KCl(aq).

Which one of the following equations is CORRECTLY balanced?

2 NF₃(g)→ N₂(g) + 3 F₂(g)

Which of the following equations is correctly balanced?

2 NH₃→ N₂ + 3 H₂

The chlorine used to purify your drinking water was made possible by electrolyzing molten NaCl to produce liquid sodium and gaseous chlorine. The balanced equation for this reaction is

2 NaCl 2 Na + Cl₂

Consider the balanced equation: 2 H₂(g) + O₂(g)→2 H₂O(l) The INCORRECT statement concerning this reaction is

2 g of hydrogen react with 1 g of oxygen to produce 2 g of water.

2 Cs(s) + 2 HOH(l)→ H₂(g) + 2 CsOH(aq) The TRUE statement about the above reaction is

2 mol of HOH(l) will produce 1 mol of H₂(g).

C₃H₈(g) + 5 O₂(g)→3 CO₂(g) + 4 H₂O(g) Which of the following statements about the above equation is TRUE?

2 molecules of C₃H₈ will react with 10 molecules of oxygen.

When the equation __CrF₃(aq) + __Ba(MnO₄)₂(aq) → __BaF₂(aq) + __Cr(MnO₄)₃(s) is balanced, the coefficients are

2, 3, 3, 2

Shawn inhales 1.8 L of oxygen at STP. What would this volume of oxygen weigh?

2.6 g

When methanol burns in a fondue heater, 2.15 L of oxygen at STP is consumed. What volume of steam is formed? (HINT: DON'T forget there is a second product!)

2.87 L

0.0239 kg = ?g

23.9 g

What is the temperature of 12°C on the Kelvin scale

285 K

0.00876 mol

3

2.97 ∙ 10⁵ m

3

4.50 g

3

7.08 ∙ 10⁻⁸ m

3

746 mL

3

__Cu₂S(s) + __O₂(g) →__Cu₂O(s) + __SO₂(g) The coefficient for oxygen in the above equation would be (use whole numbers only)

3

Sulfuric acid + aluminum hydroxide→water + aluminum sulfate The balanced chemical equation for the above word equation has coefficients of

3 + 2→6 + 1

The coefficients from left to right in the balanced equation are

3, 2→3, 2

Use this information to answer questions #70 and 71 A compound containing nitrogen and oxygen was analyzed. One mole of the compound contained 28 g of nitrogen and 48 g of oxygen. The quantity of oxygen atoms present in this sample is

3.0 mol

The following data is the result of a precipitation experiment: theoretical mass of precipitate 1.62 g mass of filter paper 0.85 g mass of filter paper and dry precipitate 2.42 g Calculate the percent error for these results.

3.1%

An acid spill or burn should be neutralized immediately with baking soda: H₂SO₄(aq) + 2 NaHCO₃(aq)→ 2 HOH(l) + 2 CO₂(g) + Na₂SO₄(aq) The mass of sodium bicarbonate required to neutralize 0.0200 mol of sulfuric acid is

3.36 g

(6.626 ∙ 10⁻³⁴ J∙s) (3.00 ∙ 10⁸ m/s)/ (5.81 ∙ 10⁻⁷ m)

3.42 ∙10⁻¹⁹ J

Use the unbalanced equation below to find the volume of steam produced in one hour if 160 kL of methane are burned in a power plant during that time. ? CH₄ + ? O₂→ CO₂ + ? H₂O

320 kL

The mass of cobalt(III) chloride necessary to react with 23.4 g of sodium sulfide is

33.0 g

Iron(II) bromide reacts with silver nitrate to form silver bromide and iron(II) nitrate. If 21.6 g of iron(II) bromide reacts, the mass of silver bromide formed is

37.6 g

Fe(s) + 3 H₂O(l)→ 3 H₂(g) + Fe₂O₃(s) When 0.750 mol of water reacts with sufficient iron, the mass of Fe₂O₃(s) produced is

39.9 g

3.502 ∙ 10⁻³ cm³

4

A piece of zinc is dropped into a silver nitrate solution with the following results: initial mass of zinc = 21.62 g final mass of zinc = 8.54 g The predicted mass of silver produced is

43.16 g

A ions have a charge of 3⁺, B ions have a charge of 1⁻. A has a molar mass of 8.00 g/mol and B has a molar mass of 12.00 g/mol. The molar mass of the compound formed when A and B combine is

44.00 g/mol

The melting point of candle wax would be BEST recorded as

45.2°C

41.6 g + 3.87 g

45.5 g

In a chemical reaction, potassium metal reacts with chlorine gas to produce potassium chloride, KCl. The mass of potassium, K, required to react with 0.60 mol of chlorine, Cl₂, is

46.9 g

When the total pressure inside a tennis ball reaches 1013 kPa, the tennis ball will burst. If the ball originally has a pressure of 405 kPa at room temperature (20C), at what temperature will the ball burst?

460C

___ C₆H₁₄ + ___ O₂ → ___ CO₂ + ___ H₂O

47

The following equation represents the manufacture of chlorine for the lumber industry from the potassium salt (potash). After balancing, calculate the mass of chlorine produced from 1.00 ton (1.00 Mg) of the salt. ? KCl→ ? K + ? Cl₂

476 kg

One step in the production of cement involves the heating of calcium carbonate, which subsequently decomposes into calcium oxide and carbon dioxide. What mass of lime (calcium oxide) can form if 1.00 kmol of calcium carbonate decomposes?

56.1 kg

Calculate the molar mass of table salt.

58.44 g/mol

Which one of the following has the greatest mass?

6.02 x 1023 atoms of zinc, Zn

___ C₁₈H₃₂+ ___ O₂→ ___ CO₂ + ___ H₂O

61

Balance these equations, then choose the total of the coefficients from the choices listed under each reaction. Example: 1 Cu + 2 AgNO₃ → 2 Ag + 1 Cu(NO₃)₂ total coefficients = 1 + 2 + 2 + 1 = 6 ___ Al + ___ Br₂ → ___AlBr₃

7

Aluminum, Al, reacts with hydrochloric acid, HCl(aq), to form hydrogen gas, H₂, and aluminum chloride, AlCl₃. If 5.0 moles of aluminum react, the quantity of hydrogen gas produced is

7.5 mol

(4.98 yr)(1.5 ∙ 10⁷ km/yr)

7.5 ∙ 10⁷ km

7.76 mol= ?mmol

7760 mmol

The molar mass of benzene is CORRECTLY written as

78.12 g/mol

Consider the following equation: __Cl₂(g) + __C₁₀H₁₆(l)→__C(s) + __HCl(g). The coefficient for Cl₂(g) in the above equation, when it is balanced, is

8

When "150 million" is put in proper scientific notation, the exponent of the ten is

8

___ H₃PO₄ + ___ NH₄OH→___ HOH + ___ (NH₄)₃PO₄

8

___ NaHSO₄ + ___ NaClO + ___ NaCl→___ Cl₂ + ___ H₂O + ___ Na₂SO₄

8

One value below is converted correctly to another unit. Which one is it?

821 mg = 0.000 821 kg

The mass of water produced when 437 g of MgBr₂ is produced is

85.5 g

If they form a precipitate, they will be ____.

A

In simple decomposition reactions, ionic compounds are ____.

A

Use this information to answer questions #133 and 134. 7.81 g of Na₂S is reacted with AlPO₄ according to the following incomplete chemical equation: __AlPO₄(aq) + __Na₂S(aq) → ? + ? The correct formulas for the products in the above reaction are

Al₂S₃ and Na₃PO₄

Why does the pressure inside a container of gas increase if more gas is added to the container?

Because there is an increase in the number of particles striking the wall of the container per unit time.

The following chemical reactions were performed and some observations were noted: CaCl₂ + ZnCO₃→ZnCl₂ + CaCO₃ — a precipitate forms HCl + Zn(OH)₂→HOH + ZnCl₂ — no precipitate forms From the above information alone it is evident that the precipitate is

CaCO₃

In replacement reactions, ionic compounds are most likely found as ____.

D

To obtain a 5.40 g sample of NaHCO₃, a student must do which of the following procedures?

Determine the mass of the empty container.

A 28.0 L gas sample at STP is weighed and found to have a mass of 21.3 g. What was the unknown gas?

NH₃

When chlorine gas is bubbled through a solution of aqueous sodium bromide, the formulas for the products formed are

NaCl and Br₂

Consider the following equation: 4 FeS₂(s) + 11 O₂(g)→2 Fe₂O₃(s) + 8 SO₂(g). Which of the statements about the above equation is FALSE?

Oxygen has 11 atoms per molecule.

Which of the following observations would NOT necessarily indicate a chemical reaction?

Solutions are mixed.

If a steel tank containing a gas experiences a decrease in temperature, what happens to the pressure of the gas inside the tank?

The pressure will decrease.

C₃H₈(g) + 5 O₂(g)→3 CO₉(g) + 4 H₂O(g) Which of the following statements about the above reaction is true?

The total mass of CO₂(g) and H₂O(g) produced is equal to the total mass of C₃H₈(g) and O₂(g) reacted.

Charles' Law

The volume of a fixed mass of gas is directly proportional to its Kelvin temperature, if the pressure is kept constant.

What device is used to measure air pressure

barometer

If calcium reacts with chlorine, the product will be called

calcium chloride

Under what temperature and pressure conditions does a real gas behave most like an ideal gas?

high temperature and low pressure

Volume ↑ Density ↓

inverse

Volume ↑ Pressure ↓

inverse

In a decomposition reaction, 216.59 g of compound broke up into 16.00 g of one element and one mole of a second element. What was the name of the second element?

mercury

The substance required for combustion is

oxygen

O₃ (g)

ozone

If a 4.0 L balloon at 90 kPa and 15C has half the gas molecules removed, the volume changes to 2.0 L. This is because

there are fewer molecular collisions with the balloon wall.