The number of molecules in 4.25 g of ammonia is approximately

Options

A. `0.5 xx 10^(23)`
B. `1.5 xx 10^(23)`
C. `3.5 xx 10^(23)`
D. `2.5 xx 10^(23)`

Answer

B

Explanation

17 g `NH_(3) = 1` mole
No.of molecules in 1 mol .`NH_(3) = 6 xx 10^(23)`
No. of molecules in 4.25 g `NH_(3)`
` = (6.02 xx 10^(23) xx 4.25)/(17) = 1.5 xx 10^(23)`