Question

How many molecules are in 0.5 grams of ammonia, NH3

Answer 1

Answer:

Number of molecules=number of moles×Avogadro's number

First we find number of moles(n)

n=mass in gram/Molar mass(g/mole)

Molar mass of NH3=14+3(1)

Molar mass of ammonia=17g/mole

Mass of ammonia=0.5g

putting the values;

n=0.5g/17g/mole

n=0.029 moles

Now put the number of moles in ;

Number of molecules=0.029×6.023×10^23

Number of molecules=1.77×10^22 molecules of ammonia are present Ans