Question

Exercise 11.106---

Part B Consider the reaction: 2NiO(s)→2Ni(s)+O2(g) If O2 is collected over water at 40 ∘C and a total pressure of 747 mmHg , what volume of gas will be collected for the complete reaction of 25.51 g of NiO?

Answer 1

2NiO(s)→2Ni(s)+O2(g)

gram molar mass of NiO = 74.6928g.mole

no of moles of NiO   = W/G.M.Wt

                                 = 25.51/74.6928   = 0.34moles

from the balanced equation

2 moles of NiO decomposes to gives 1 moles of O2

0.34 moles of NiO decomposes to gives = 1*0.34/2   = 0.17 moles of O2

Total pressure    = 747mmHg

water vapor pressure at 40⁰C    = 55.3mmHg

Total pressure      = partial pressure of O2 + water vapor pressure

partial pressure of O2   = total pressure - water vapor pressure

                                      = 747-55.3   = 691.7mmHg

partial pressure of O2   = 691.7/760   = 0.91atm

T = 40 +273   = 313K

n = 0.17 moles

PV = nRT

V   = nRT/P

       = 0.17*0.0821*313/0.91   = 4.8L

volume of oxygen gas = 4.8L >>>>>answer