Question

The equation below shows the decomposition of lead nitrate. How many grams of oxygen are produced when 4.60 g NO is formed? Pb(NO3)2 (s) → PbO (s) + NO2 (g) + O2 (g) please show all the work

Answer 1

the moles of oxygen produced when 4.60 g No2 is formed is calculated as below

find the moles of NO2 = mass/molar mass
= 4.60g/46 g/mol = 0.1 moles

2Pb(NO3)2 = 2PbO +4 NO2 +O2

by use of mole ratio between No2 to O2 which is 4:1 the moles of O2
= 0.1 x1/4 = 0.025moles

mass of O2 = moles x molar mass

= 0.025 moles x 32 g/mol = 0.8 grams of oxygen

Answer 2

0.8 g of O₂

Solution:

The balance chemical equation is as follow,

2 Pb(NO₃)₂ → 2 PbO + 4 NO₂ + O₂

According to equation,

184 g (4 moles) NO₂ is produced along with = 32 g (1 mole) O₂ gas

So,

4.60 g NO₂ when formed will produce along = X g of O₂

Solving for X,

X = (32 g × 4.60 g) ÷ 184 g

X = 0.8 g of O₂