Question

A sample of NH₃ weighs 3.956 g. How many molecules of NH₃ are in the sample?

Your answer should be in scientific notation, to three significant figures. Type the letter "x" or "e" in the answer field when you are ready to enter the power of 10.

     molecules of NH₃ 

Answer 1

N=n÷N_A

Where; N= no of Molecules

n= No of mole

N_A= 6.022×10²³

n= Mass/molar mass

Molar mass of NH₃ = 14+3 = 17

n = 3.956÷17= 0.2327 mol

N= 0.2327×6.022×10²³

No of Molecules = 1.4×10²³