Answer:
19.6 g rounded to the nearest tenth
Explanation:
First we have to find the number of moles of CuO.
n=m/M
M CuO = 63.5 x 16
79.5 g/mol or gmol-1
M N2= 2×14 = 28g/mol
167/79.5= 2.1 mol CuO
3 moles of Cuo = 1 mole of N2
2.1 moles of Cuo = x mole of N2
2.1x1/3=0.7 mole of N2
n=m/M
m=nxM
m=0.7 x 28 = 19.6 g N2
So 19.6 g of N2
Hope this helps!