Consider the reactionSolutionmoles of NiO used 2478gm7469 g

Consider the reaction:

Solution

moles of NiO used = 24.78gm/74.69 gmmol^-1 = 0.332 moles

According to the reaction stoichiometry 1 mole of O2 gas is formed from 2 moles of NiO. So, number of moles of O2 produced from 0.332 moles NiO = 0.332/2 =0.166 moles.

PV = nRT P = 745 mmHg = 745/760 = 0.98 atm, T 273 + 40 = 313 K

or, V = nRT/P

or, V = 0.166 *0.082 Latm/K/mol * 313K/0.98 atm = 4.35 L

4.35 L O2 gas will be collected.