Answer: -
Mass of Magnesium strip 0.028 g
Atomic mass of magnesium = 24g mol-1
Number of moles of magnesium = Mass / atomic mass
= 0.028 g / 24 g mol-1
= 1.167 x 10^-3 moles
The balanced chemical equation for this process is
Mg(s) + 2HCI(aq) → H2(g) + MgCI2(aq)
We see from the equation,
1 mole of Mg will give 1 mole of H2.
1.167 x 10^-3 mol of Mg will give 1.167 x 10^-3 moles of H2.
Barometric Pressure =1.1 atm
Vapor pressure of water vapor = 22.4 torr = 0.029 atm
Pressure of dry gas P = 1.1 -0.029 =1.071 atm
Temperature T = 24 C + 273 =297 K
Using the relation
PV = nRT
V = nRT / P
= 1.167 x10^-3 mol x 0.082 L atm K−1 mol−1 x 297 K / 1.071 atm
=0.0265 L
Theoretical yield = 0.0265 L
Actual Yield = 32.2mL = 0.0322 L
% yield = actual x 100 / Theoretical
= 0.0322 x 100 / 0.0265
= 121.5%