Solving Collecting Gas Over Water Problems

This video tutorial covers gas collection over water problems, focusing on calculating partial pressures and using the ideal gas law to determine moles and mass. It includes examples involving nitrogen gas, zinc reacting with hydrochloric acid, and the decomposition of potassium chlorate. The tutorial explains how to account for vapor pressure and convert between units, providing step-by-step calculations for each problem.

What is the first step in solving a gas collection over water problem?

• Determine the partial pressure of the collected gas.

• Identify the molar mass of the gas.

• Measure the volume of the gas collected.

• Calculate the total pressure of the gas.

What is the role of the vapor pressure of water in gas collection over water problems?

• It increases the total pressure of the collected gas.

• It is added to the gas's partial pressure to find the total pressure.

• It has no effect on the calculations.

• It is subtracted from the total pressure to find the gas's partial pressure.

How do you convert torr to atm in gas calculations?

• Divide by 760

• Divide by 101.3

• Multiply by 760

• Multiply by 101.3

What is the molar mass of nitrogen gas (N2)?

• 16.00 g/mol

• 28.02 g/mol

• 32.00 g/mol

• 14.01 g/mol

What is the balanced equation for zinc reacting with hydrochloric acid?

• Zn + 2HCl -> ZnCl2 + H2

• Zn + H2SO4 -> ZnSO4 + H2

• Zn + 2HCl -> ZnCl + H2O

• Zn + HCl -> ZnCl + H2

How is the partial pressure of hydrogen gas calculated in the reaction of zinc with hydrochloric acid?

• By subtracting the vapor pressure of water from the total pressure

• By dividing the total pressure by the vapor pressure of water

• By adding the vapor pressure of water to the total pressure

• By multiplying the total pressure with the vapor pressure of water

What is the molar mass of zinc?

• 65.39 g/mol

• 72.61 g/mol

• 54.94 g/mol

• 58.93 g/mol

What is the correct balanced equation for the decomposition of potassium chlorate?

• KClO3 -> KCl + O2

• 2KClO3 -> 2KCl + O2

• 2KClO3 -> 2KCl + 3O2

• 2KClO3 -> KCl + 3O2

What is the molar ratio of oxygen gas to potassium chlorate in the decomposition reaction?

• 3:2

• 1:2

• 2:3

• 1:1

How do you calculate the mass percent of a compound in an impure sample?

• Multiply the total mass of the sample by the mass of the compound and divide by 100

• Divide the mass of the compound by the total mass of the sample and multiply by 100

• Multiply the mass of the compound by the total mass of the sample and divide by 100

• Divide the total mass of the sample by the mass of the compound and multiply by 100