sulphur burns in oxygen to give sulphur dioxide. if 16 g of sulphur dioxide burns in x cc. of oxygen, calculate the amount of potassium nitrate which must be heated to produce x cc of oxygen.

Asked by drashtichauhan75 | 21st Mar, 2019, 07:35: PM

Expert Answer:

The reaction for burning of sulphur is, 

 

space space straight S space space space space space space plus space space space straight O subscript 2 space space space rightwards arrow space space space SO subscript 2 space
1 mol space space space space space space space 1 mol space space space space space space space space 1 mol

 

We know, 

 S = 32, K = 39 , N = 14, O = 16

Moles of S reacted =

 16 over 32 equals space 0.5 space mol

0.5 mol of S needs 0.5 mol of Oxygen,

To create confusion, x cc is mentioned in the question, which has no significant use.

So we know that Sulphur burns in 0.5 mol Oxygen.

The thermal decomposition of Potassium nitrate :


space space space 2 KNO subscript 3 space space rightwards arrow space space 2 KNO space space plus space space straight O subscript 2 space
space space space space 2 mol space space space space space space space space space space space space space space space space space space space space space space space space space 1 space mol space space
​ left square bracket 2 space straight x space 101 straight g right square bracket space space space space space space space space space space space space space space space space space space space space 32 space straight g space


2 mols of KNO3 gives 1 mol of O2 
0.5 mol of Owill be produced by 1 mol of KNO3

1mol of KNO3 = 101 g

Therefore the amount of  KNO3 required to produce oxygen is 101 g.

Answered by Varsha | 21st Mar, 2019, 09:03: PM