Question

Two elements X and Y have atomic mass of X = 75 and Y = 16 combine to give a compund having 76% of X. Then formula of compund is

1. XY

2. X2Y

3. X2Y2

4. X2Y3

Answer 1

Element X = 75 u

Element Y = 16 u

Mass % of compound = 100%

Mass % of X in compound = 76%

Mass % of Y in compound is = 100% - 76% = 24%

Mass Ratio of X = 76 / 75 * 100 = 1.01

Mass Ratio of Y = 24 / 16 = 1.50

Dividing by the least multiple obtained we get,

X = 1.01 / 1.01 = 1 mole

Y = 1.5 / 1.01 = 1.48 which is approximately 1.5

So multiplying by common factor 2 we get,

X = 1 * 2 = 2 moles

Y = 1.5 * 2 = 3 moles

Hence formula = X₂Y₃

Option 4 is correct option

Answer 2

the correct answer is X2Y3