What is the mass in grams of ammonia gas in 1.204 x 10^24 molecules of ammonia gas, NH^3, at STP?

Mass of ammonia = 34 g

Explanation:

Given dа ta:

Number of molecules of ammonia = 1.204 * 10²⁴

Mass of ammonia = ?

Solution:

First of all we will calculate the number of moles.

one mole of ammonia = 6.022 * 10²³ molecules

n = 1 mole/6.022 * 10²³ molecules * 1.204 * 10²⁴ molecules

Number of moles = 2 mol

Mass of ammonia:

Number of moles = Mass / molar mass

Mass of ammonia = number of moles * molar mass

Mass of ammonia = 2 mol * 17 g/mol

Mass of ammonia = 34 g