The combustion of butane produces heat according to the equation  2C4H10(g) + 13O2(g) -> 8CO2(g) + 10H2O(l)    Δ{“version”:”1.1″,”math”:”Δ”}H°rxn = –5,314 kJ/mol  What is the heat of combustion per gram of butane?

If the pressure of a gas sample is quadrupled and the absolute temperature is doubled, by what factor does the volume of the sample change?

1.018 g of Freon-113 gas is trapped in a 145 mL container at 760. mmHg and 50.0°C.  What is the molar mass of Freon-113?

Hydrogen iodide decomposes according to the equation 2HI(g)   ↔   H2(g) + I2(g), for which Kc = 0.0156  at 400ºC.  0.550 mol HI was injected into a 2.00 L reaction vessel at 400ºC. Calculate the concentration of HI at equilibrium.

For the following reaction at equilibrium, which one of the changes below would cause the equilibrium to shift to the left? 2NOBr(g)   ↔   2NO(g) + Br2(g),     DHºrxn = 30 kJ/mol

Choose the response that lists the member of each of the following pairs that has the higher boiling point. (I) H2O or KI       (II) HF or HI      (III) Cl2 or Br2

0.204 g of an unknown compound dissolved in 180 mL of water has an osmotic pressure of 26.2 mmHg at 24.0°C.  Calculate the molar mass of the compound. (R = 0.0821 L·atm/K·mol)

For the reversible reaction SO2(g) + NO2(g)   ↔   SO3(g) + NO(g), the equilibrium constant is 18.0 at 1,200ºC.  If 1.0 mole of SO2 and 2.0 moles of NO2 are placed in a 20 L container, what concentration of SO3 will be present at equilibrium?

A 0.10 M NH3 solution is 1.3% ionized.  Calculate the H+ ion concentration.             NH3 + H2O → NH4+ + OH–

What is the osmotic pressure of a solution that contains 16.2 g of propyl alcohol (C3H7OH) dissolved in enough water to make 400 mL of solution at 27°C?