Calculating the Number of Molecules of Ammonia in 3.4g

To calculate the number of molecules of ammonia in 3.4g, we need to use the Avogadro's number and the molar mass of ammonia.

Step 1: Determine the Molar Mass of Ammonia

The molar mass of ammonia (NH3) can be calculated by adding up the atomic masses of nitrogen and hydrogen:

Molar mass of NH3 = (1 x atomic mass of N) + (3 x atomic mass of H)
Molar mass of NH3 = (1 x 14.01 g/mol) + (3 x 1.01 g/mol)
Molar mass of NH3 = 17.03 g/mol

Step 2: Calculate the Number of Moles of Ammonia

Using the formula:

Number of moles = mass / molar mass

We can calculate the number of moles of ammonia in 3.4g:

Number of moles of NH3 = 3.4g / 17.03 g/mol
Number of moles of NH3 = 0.2 mol

Step 3: Calculate the Number of Molecules of Ammonia

Using the Avogadro's number, we can convert the number of moles of ammonia to the number of molecules of ammonia:

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

Number of molecules of NH3 = 0.2 mol x 6.02 x 10^23 molecules/mol
Number of molecules of NH3 = 1.204 x 10^23 molecules

Therefore, there are 1.204 x 10^23 molecules of ammonia in 3.4g.