chem final exam

A sealed plastic bag is filled with 1 L of air at STP. You accidentally sit on the bag. The maximum pressure the bag can withhold before popping is 500 kPa. What is the internal volume of the bag at the instant of popping?

.20L

If 24.5 g of iron are placed in 1.00 L of 0.25 M HCl, how many grams of iron (II) chloride are obtained? Identify the limiting and excess reactants. How much excess reactant is left over?

.25 grams FeCl2. Limiting: Iron II Chloride Excess: Iron Excess left over: 30.63g

The volume of a whoopee cushion is 0.45 L at 27º C and 105 kPa. Kailey has placed the cushion on the chair of her favorite teacher. Unbeknownst to Kailey, this particular cushion has a defect and will not have the flatulence effect when sat upon. So, when the teacher sits on the cushion there is no effect. The cushion sustains the pressure exerted by the teacher so the internal pressure becomes 200 kPa and the cushion is warmed to 37º C. At last, and to Kailey's profound satisfaction, the cushion explodes. What volume of air does it expel?

.25L

What molarity of hydrochloric acid would you start with if you 1000 mL of a solution that is diluted to 100.0 mL of a 0.0493 M solution?

.493

The internal volume of a plastic bottle is 0.5 L at 1 atm. When he sees that there will be stoichiometry on the exam, Marquise gets so excited he squeezes the bottle to a pressure of 1.25 atm. What is the final volume of the bottle?

.4L

If 45 mL of water are added to 250 mL of a 0.75 M solution, what will the molarity of the diluted solution be?

.64

Greg inflates the team's footballs to 12 psi in the locker room where the temperature is 18º C. After practice he forgets to collect all of the footballs and leaves one outside where the temperature reaches 35º C. What is the final pressure of the football?

.85atm

What is the mass percent of a solution created by adding 10 g of olive oil to 90 g of vegetable oil?

100%

A container with 17.3 grams of nitrogen gas is placed in a room with a temperature of 23 ºC and a pressure of 777 torr. What is the volume of the container?

14.8L

Always helpful, Destin persuades his little sister Shelby that her Very Special Birthday Balloon will last much longer if she puts it in the freezer in the basement for a little while. The temperature in the house is 20º C at a pressure of 1.0 atm. The balloon has an initial volume of 0.25 L. If the balloon has collapsed to 2.00 L and the pressure drops to 0.88 atm by the time Shelby catches on to Destin's devious deed, what is the temperature inside the freezer? What is it in ºC?

140.8C

Zinc reacts with hydrochloric acid to produce zinc chloride and hydrogen. How many moles of HCl are required to produce 7.50 moles of ZnCl2?

15 moles

When 9.34 g of zinc react with excess hydrochloric acid how many grams of zinc chloride will be produced?

19.4g

How many grams of NaBr are needed to make 50 g of a 5.0% solution?

2.5g

A red rubber dodgeball sits in a 20º C basement filled with 3.5 L of compressed air. Eager to begin practice for the impending dodge ball season, Renard takes the ball outside. After a few hours of practice, the ball has a volume of 3 L. What is the temperature outside?

251K

___ NaBr + ___ Ca(OH)2 🡪 ___ CaBr2 + ___ NaOH ___ NH3 + ___H2SO4 🡪 ___ (NH4)2SO4 ___ C5H9O + ___ O2 🡪 ___ CO2 + ___ H2O ___ Pb + ___ H3PO4 🡪 ___ H2 + ___ Pb3(PO4)2 ___ Li3N + ___ NH4NO3 🡪 ___ LiNO3 + ___ (NH4)3N ___ HBr + ___ Al(OH)3 🡪 ___ H2O + ___ AlBr3

2NaBr + Ca(OH)2 -> CaBr2 + 2NaOH / Double Replacement 2NH3 + H2SO4 -> (NH4)2SO4 / Synthesis 4C5H9O + 27O2 -> 20CO2 + 18H2O / Combustion 3Pb + 2H3PO4 -> 3H2 + Pb3(PO4)2 / Single Replacement Li3N + 3NH4NO3 -> 3LiNO3 + (NH4)3N / Double replacement HBr + 3Al(OH)3 -> H2O + AlBr3 / Double replacement

5.0 grams of sugar are dissolved in 150 grams of water. What is the percent by mass of this solution?

3.2%

What is the percent by volume of solution formed by adding 15 mL of acetone to 28 L of water?

35%

How many grams of iron (III) chloride are produced when 15.3 g of iron react with excess chlorine gas?

44.0g

_____ Al + _____ O2 🡪 _____ Al2O3 _____ Cu + _____ AgNO3 🡪 _____ Ag + _____ Cu(NO3)2 _____ Zn + _____ HCl 🡪 _____ ZnCl2 + _____ H2 _____ Fe + _____ Cl2 🡪 _____ FeCl3

4Al + 3O2 -> 2Al2O3 2Cu + 2AgNO3 -> 2Ag + 2Cu(NO3)2 Zn + 2HCl -> ZnCl2 + H2 2Fe + 3Cl2 -> 2FeCl3

How much 0.075 M NaCl solution can be made by diluting 450 mL of 9.0 M NaCl?

54L

A container with a volume of 15.0 L contains oxygen. The gas is at a temperature of 29.0º C and a pressure of 1.00 x 104 kPa. How many moles of gas occupy that container?

59.7 moles

Zinc metal reacts with chromium (III) nitrate in a single replacement reaction. How many grams of zinc are required to react with 425 mL of 0.25 M chromium (III) nitrate? First, write a balanced equation.

6.91 moles

How much solute was used to make a 40% solution of NaCl in H2O if 150 grams of water were used?

60g

Copper metal reacts with silver nitrate to form silver and copper (II) nitrate. How many grams of copper are required to form 250 g of silver?

74g

What is the volume, in mL, of a 1.7M solution that contains water and 284 grams of C6H12O6?

928mL

What is the empirical formula of a molecule containing 65.5% carbon, 5.5% hydrogen, and 29.0% oxygen? If the molar mass of this compound is 110 grams/mole, what is the molecular formula?

C3H3O C3H3O

Hydrogen combines with fluorine to form hydrogen fluoride. Iron combines with water to form iron (III) oxide and hydrogen gas. Potassium iodide and chlorine combine to form potassium chloride and iodine. Potassium chlorate decomposes to form potassium chloride and oxygen.

H2 + F2 -> 2HF Fe + 3H2O -> FeO3 + 3H2 2KI + Cl2 -> 2KCl + I2 2KClO3 -> 2KCl + 3O2

What is the empirical formula of a molecule containing 18.7% lithium, 16.3% carbon, and 65.0% oxygen? If the molar mass of this compound is 73.8 grams/mole, what is the molecular formula?

Li2CO3 Li2CO3

If 25.3 g of aluminum reacts with 25.3 g of copper (II) sulfate, how many grams of copper are formed? Identify the limiting and excess reactants. How much excess reactant is left over?

Limiting: Copper III Sulfate Excess: Aluminum Excess left over: 22.4g

When 16.3 g of magnesium and 4.52 g of oxygen gas react, how many grams of magnesium oxide will be formed? Identify the limiting and excess reactants. How much excess reactant is left over?

Limiting: Oxygen gas Excess: Magnesium Excess left over: 9.52g

A solution is prepared by mixing 1.0 grams of benzene (C6H6) in 100 g of water to create a solution total volume of 100 ml. Calculate the molarity, mass percent, and molality of benzene in the solution.

Molarity: .13 Molality: .13 Mass percent: .01

Calculate the molarity of a solution that contains 1.22 grams of hemoglobin (MW = 68300) in 165 ml of solution.

Molarity: 1.08 x 10^-4

If 12.5 g of copper react with excess chlorine gas, then 25.4 g of copper (II) chloride are produced. Find the theoretical and percent yields.

Percent: 96% Theoretical: 26.2g

If 6.57 g of iron react with an excess of hydrochloric acid, then 11.2 g of iron (II) chloride are obtained in addition to hydrogen gas. Find the theoretical and percent yields.

Theoretical: 14.9g Percent: 75%

If 5.45 g of potassium chlorate are decomposed to form potassium chloride, 1.75 g of oxygen gas are also given off. Find the theoretical and percent yields.

Theoretical: 2.1g Percent: 82%