Question

Q.3

What volume of oxygen at 18°C and 750 mm pressure can be obtained from 10g of potassium
chlorate?
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Answer 1

Explanation:

2 KCIO3 = 2 KCI + 3 02

Molar mass of KCIO3 = 123g/mol

Mass of 2KCLO3 = 123x2 = 246g

Molar gas volume at STP = 22.4 litres

246g of KCIO3 give 3x22.4 = 67.2 litres of 02

10g would produce = (10x67.2)/246 = 2.73 liters

This is the volume that would be produced at STP

We convert it to the volume at 18C and 750mm pressure

p1 = 760, v1, 2.73, t1 = 273 K

p2 = 750, v1 = ?, t2 = 18+273 = 291K

p1v1/t1 = p2v2/t2

760x2.73/273 = 750xv2/291

v2 = 2.95 litres