Question

Consider the chemical reaction: 2 cu(no3)2→ 2 cuo (s) + 4 no2 (g) + o2 (g)when 9.378 g of cu(no3)2 completely decomposed, how many liters of gas will be produced at 273 k and 1 atm? the molar mass of cu(no3)2 is 187.56 g/mol.a) 0.56
b.1.12c) 2.24
d.2.80e) 3.92

Answer 1

2Cu(NO3)2 ---------->    2CuO (s) +4NO2 (g) + O2(g)

9.378g=0.05moles   

no of moles = weight / MW = 9.378/187.56 = 0.05moles

as per the above reaaction 2moles of Cu(NO3)2 can produce 4moles of N2

                                                    0.05moles Cu(NO3)2 can produce (0.05*4)/2 = 0.1moles of N2

and 2moles of Cu(NO3)2 can produce 1moles of O2

       0.05moles Cu(NO3)2 can produce (0.05*1)/2 = 0.025moles of O2

Total moles of gas i.e., N2 and O2 =0.1+0.025 = 0.125moles

From PV = nRT

       V = nRT/ P = 0.125*0.0821*273 = 2.80166Lit option is correct