How many atoms are present in 4 ml of `NH_(3)` at STP?

Explanation

22400 ml of `NH_(3)` contains `=4 xx 6.022 xx 10^(23)` atoms [`NH_(3)` contains 4 atoms]. 1 ml of `NH_(3)` contains `=(4 xx 6.022 xx 10^(23))/22400 =1.07 xx 10^(20)` atoms. 4 ml of `NH_(3)` contains `=(4 xx 1.07 xx 10^(20)` = 4.30 xx 10^(20)atoms.