Stoichiometry and Chemical Reactions

• A compound is 92.2% Carbon and 7.8% Hydrogen by mass.
• The empirical formula for the compound is C2H2.
• A compound containing carbon and hydrogen with an empirical formula of CH3 has a molecular mass of about 30.08 g/mole.
• C2H6 is the molecular formula.
• Molarity of H2O in 1.00 L of pure water, assuming a density of 1.00 g/mL, needs to be calculated.
• 50.0 mL of a 10.0 M HNO3(aq) solution is diluted to a final volume to obtain a 2.0 M HNO3(aq) solution, this requires calculation.
• A 2.500 M solution of propylene glycol (MM=76.09 g/mol) in water has a density of 1.030 g/mL.
• The mass percent of propylene glycol in water needs to be calculated.

Balancing the reactions

• The coefficient in front of O2(g) after balancing the reaction C2H2(g) + O2(g) -> CO(g) + H2O(g) should be provided.
• The spectator ion in the reaction Ag+(aq) + NaCl(aq) -> AgCl(s) + Na+(aq) can be either: Ag+(aq), NaCl(aq), AgCl(s), Na+(aq), or Cl-(aq).
• The oxidation state of nitrogen in NaNO3 must be determined.
• In the unbalanced combustion reaction C2H2(g) + O2(g) -> CO(g) + H2O(g), the reducing agent is one of the following: carbon, hydrogen, or oxygen.
• Alternatively, there might be no reducing agent in this unbalanced combustion reaction.
• 8.08 g of H2(g) reacts with an excess of O2(g) to form 54.06 g of H2O(g) in the reaction 2 H2(g) + O2(g) -> 2 H2O(g).
• The percent yield for this reaction needs to be determined.
• A 20.00 mL sample of aqueous HCl is titrated with 15.00 mL of 0.100 M NaOH(aq).
• The molarity of the HCl solution in mM must be calculated.
• Given the balanced reaction 2 C2H2(g) + 5 O2(g) -> 4 CO2(g) + 2 H2O(g), 13.02 g of C2H2(g) is combusted in the presence of excess oxygen.
• The mass of CO2(g) produced needs to be determined.
• The pressure in atmospheres needs to be calculated for two moles of gas at 273.15 K in a container with a volume of 11.2 liters.

Matching Gas Laws

• Avogadro's Law describes the relationship between moles and volume.
• Boyle's Law describes the relationship between pressure and volume.
• Charles's Law describes the relationship between volume and temperature.

Proportionality matching

• Moles and volume are directly proportional.
• Pressure and temperature are directly proportional.
• Volume and temperature are directly proportional.
• Moles and pressure are inversely proportional.
• A gas sample has a volume of 20.5 L at 300.0 K and 2.00 atm.
• The volume of the gas at 1.00 atm and 150.0 K must be determined.
• The root mean squared speed of He(g) in the room, if the temperature of the room is 30.0 °C must be determined.
• For a 2.00 mol sample of Cl2(g) at 300.0 K and a pressure of 2.00 atm, the van der Waals' volume (in liters) must be calculated.
• For Cl2(g), a = 6.49 L² atm/mol² and b = 0.0652 L/mol
• The van der Waals equation is given by [P + a(n/V)^2](V-nb) = nRT
• The value of the $b$ parameter increases, the van der Waals' volume becomes less than the ideal volume under conditions of constant temperature and constant moles in the van der Waals equation..

Calculations based on balancing equations. Includes empirical and molecular formulas. Also covers molarity, dilutions, and mass percent calculations in solutions.