Chem Gas Worksheet 5.
Block: ____ Teacher: ________________ Name: ___________________________________
I. Molecular mass and gas density.
a. 5.87 g of gas occupy 1.45 L at 28°C, 98.8kPa. (i) How many moles of gas is it? (ii) What is the
molecular weight of the gas? (Hint: What are the units of molecular weight?)
i. ____________ mol
ii.____________ g/mol
b. 15.3 g of gas occupied 996 ml at 75°C, 198kPa. What is the molecular mass of the gas?
______________ g/mol
c. What is the molecular weight of a gas which has a density of 3.78 g/L at 95°C, 920mmHg?
(Hint: 1L = ?g, ?mol)
______________ g/mol
d. What is the density of CH4(g) at SATP? (Hint: 1 mol = ?g, ?L)
______________ g/L
e. What is the density of SO2(g) at 822K, 0.278atm?
______________ g/L
f. What is the density of C2H6(g) at -113°C, 9.25 psi?
______________ g/L
g. 87.3 cm3 of gas was collected over water at 22°C, atmospheric pressure 96.8kPa. The gas
was found to weigh 0.350 g. What was the molecular weight of the gas?
______________ g/mol
J. Stoichiometry.
a. How many liters of O2 gas, measured at SATP, are needed to completely burn 3.0 L of CH4(g)
at SATP? How many liters of CO2(g) at SATP are produced? (WRITE BALANCED EQUATION
FIRST!)
_____________ L O2
_____________ L CO2
b. How many liters of hydrogen gas are needed to produce 6.295 L of ammonia, NH 3, both
measured at the same temperature and pressure?
______________ L H2
c. What volume of oxygen gas, measured at 35°C and 115 kPa, is required to completely burn
50.0 g of Mg?
______________ L O2
d. Your “Mass Relations in Chemical Reactions” lab reacted sodium carbonate with hydrochloric
acid, producing carbon dioxide, water, and sodium chloride. If you used exactly 2.00 g of sodium
carbonate and excess HCl, what volume of CO2 would be produced, measured at 22°C,
752mmHg?
___________cm 3 CO2
e. Aluminum reacts with sulfuric acid in a single replacement reaction. Hydrogen gas is one of
the products. What volume of hydrogen gas, collected over water at 25°C and at an atmospheric
pressure of 766mmHg, could be obtained by the reaction of 3.25 g of Al with 22.5 g of H2SO4?
(Hint: Look in your notes for “limiting reagent” problems!)
______________L H2