CHM 40 HW/Class Activity - Chapter 13 Name
I. Carry out these conversions
a. 352 torr to kPa
b. 0.255 atm to mm Hg
II. Boyle’s law
1. Freon-12 (the common name for the compound CCl2F2) was widely used in refrigeration systems, but has now been replaced by other compounds and that do not lead to the breakdown of the protective ozone in the upper atmostphere. Consider a 1.5 L sample of gaseous CCl2F2 at a pressure of 56 torr. If pressure change to 150 torr at at constant temperature,
Will the volume of the gas increase of decrease?
What will be the new volume of the gas?
2. A sample of gas collected in a 350 cm3 container exerts a pressure of 103 kPa. What would be the volume of this gas at 150 kPa of pressure? (Assume that the temperature remains constant.)
3. A sample of helium gas at 25°C is compressed from 200 cm3 to 0.240 cm3. Its pressure is now 3.00 cm Hg. What was the original pressure of the helium?
III. Charles’ Law
1. A 250 cm3 sample of neon is collected at 44.0 oC. Assuming the pressure remains constant, what would be the volume of the neon at standard temperature?
2. A balloon at 31°C is filled with 20 L of gas. What would its volume be at a temperature of 51°C if the pressure did not change
3. A gas is warmed until its volume is 20 L. Orginally it occupied a volume of 12 L at 71°C. The pressure did not change. What is it Kelvin temperature now?
IV. Avogadro’s Law
1. A chemical reaction occurring in a cylinder equipped with a moveable piston produces 0.621 mol of a gaseous product. If the cylinder contained 0.120 mol of gas before the reaction and had an initial volume of 2.18L, what was its volume after the reaction? (Assume constant pressure and temperature)
2. A 4.65-L sample of helium gas contains 0.225 mol of helium. How many additional moles of helium gas must be added to the sample to obtain a volume of 6.48L? Assume constant pressure and temperature
V. Ideal Gas Law;
1. A sample of hydrogen gas is mixed with water vapor. The mixture has a total pressure of 755 torr and the vapor water has a partial pressure of 24 torr. What amount (moles) of hydrogen gas is contained in 1.55L of this mixture at 298K?
2. An aerosol spray can with a volume of 350ml contains 3.2 g of propane gas (C3H8) as propellant. What is the pressure (in atm) of gas in the can at 20.0oC?
3. A typical high-pressure tire on a racing bicycle might have a volume of 365 mL and a pressure of 7.80 atm at 25oC. Suppose the rider filled the tire with helium to minimize weight. What is the mass of the helium in the tire?
VI. Gas Stoichiometry
1. Calculate the volume of oxygen gas produced at 1.00 atm and 25oC by the complete decomposition of 10.5 g of potassium chlorate. The balance equation for the reaction is
2 KClO3(s) à 2 KCl(s) + 3 O2(g)
2. Ammonium nitrate can decompose explosively when heating according to the equation
2 NH4NO3(s) à 2 N2(g) + 4 H2O(g) + O2(g)
How many liters of gas would be formed at 450oC and 1.00 atm pressure explosion of 450 g of NH4NO3?
3. A foul-smelling gas produced by the reaction of HCl with Na2S was collected, and a 1.00 L sample was found to have a mass of 1.52 g at STP. What is the molecular mass of the gas? What is its likely formula and name?