volume of Hydrogen gas?

Question

The volume of hydrogen gas at 38.0ᵒC and 763 torr that can be produced by the reaction of 4.33 grams of zinc with excess sulfuric acid is

Answer 1

The reaction in question is Zn(s) + H2SO4(aq) ==> ZnSO4(aq) + H2(g)

We can use the Ideal Gas Law: PV = nRT to solve for V (volume of gas), after we find n, moles of H2 gas.

moles of Zn = 4.33 g Zn x 1 mol Zn/65.4 g = 0.0662 moles Zn

moles H2 = 0.0662 moles Zn x 1 mol H2/mol Zn = 0.0662 mole H2 gas

Solving the ideal gas law for V, we have

V = nRT/P and T is in Kelvin so T = 38 + 273 = 311K and P is converted to atm as 763 torr/760 = 1.00 atm

V = (0.0662 mol)(0.0821 Latm/Kmol)(311K)/1.00 atm

V = 1.69 L