Question #669e0

1 Answer
Feb 20, 2017

a. Limiting reagent = Cu
b. mass of NO2 produced = 27.324g

Explanation:

Given mass of Cu = 18.9g
Molar mass of Cu 63.55 g/mol
No. of moles of Cu = 18.963.55 = 0.297moles ............(1)

Given Conentration of Nitric acid = 16 mol/L
Volume = 82ml = 0.082L
Molarity = nV
where n = no. of moles of HNO3 and V= volume in L
n = 160.082 = 1.312 moles .................(2)

Chemical equation
Cu + 4HNO3 --> Cu(NO3)2 + 2H2O + 2NO2

According to equation
1 mole of Cu produces 2 moles of 2NO2
so, 0.297 moles of Cu will produce 2NO2 = 2 X 0.297 = 0.594 moles...................(3)

In equation
4 moles of 4HNO3 produces 2 moles of 2NO2
so, 1.312 moles of 4HNO3 will produce 2NO2 = (2 x 1.312)/ 4 = 0.656 moles ............(4)

As given moles of Cu produces lesser moles of 2NO2 hence Cu is the limiting reagent

a. The limiting reagent in the reaction is Copper

b. As solved above
0.297 moles of Cu will produce 2NO2 = 2 X 0.297 = 0.594 moles

2NO2 produced = 0.594 moles
Molar mass of 2NO2 = 46 g/mol
mass = 0.594 moles X 46 g/mol = 27.324g

2NO2 = 27.324g