Question

Cortisone is a molecular substance substance containing `21` atoms of carbon per molecule. The mas percentage of carbon in cortisone is `69.98%`. Its molar mass is :
A. `176.5`
B. `252.2`
C. `287.6`
D. `360.1`

Answer 1

Correct Answer - D
`wt` of carbon `=21xx12 g`
`because 69.98 g` carbon contain `100 g` cortisone
`therefore 1 g` carbon contain `100 g `cortisone
`=(100)/(69.98)`
`therefore 21 xx 12 g rarr =(100)/(69.98)xx21xx12=360.10`