Question

Calculate the number of oxygen atoms in 29.34 g of sodium sulfate, na2so4 .

Answer 1

Answer: The number of oxygen atoms in given mass of sodium sulfate are $4.96\times 10^{23}$

Explanation:

To calculate the number of atoms, we first need to find the number of moles of sodium sulfate. the equation used will be:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of sodium sulfate  142g/mol

Given mass of sodium sulfate = 29.34g

Putting values in above equation, we get:

$\text{Moles of }Na_2SO_4=\frac{29.34g}{142g/mol}=0.206mol$

In 1 mole of sodium sulfate, 4 moles of oxygen atoms are present.

Number of oxygen atoms present in 1 mole of sodium sulfate will be $4\times 6.022\times 10^{23}$

So, in 0.206 mol of sodium sulfate, the number of oxygen atoms will be = $0.206\times 4\times 6.022\times 10^{23}=4.96\times 10^{23}$

Hence, the number of oxygen atoms in given mass of sodium sulfate are $4.96\times 10^{23}$

Answer 2

To determine the amount of oxygen atoms in the compound given, we need convert it in terms of moles and relate the number of atoms O per mole of the compound. From there, we use the avogadro's number to convert it into atoms.

29.34 g Na2SO4 ( 1 mol / 142.04 g ) ( 4 mol O / 1 mol Na2SO4 ) (6.022x10^23 atoms O / 1 mol ) ) = 4.98x10^23 atoms O