Test Index

WAEC Chemistry 2018 Paper

Question : 32

Total: 50

N_{A} = 6.02 \times 10^{23}

Solution:

Concept:

Nitrogen is a diatomic gas, so 1 mole of

\mathrm{N}_2

contains 2 moles of nitrogen atoms.

Explanation:

Number of moles of nitrogen gas =

0.2\ \text{mol}

Moles of nitrogen atoms =

0.2 \times 2 = 0.4\ \text{mol}

Number of atoms = moles of atoms × Avogadro's constant.

= 0.4 \times 6.02 \times 10^{23}

= 2.408 \times 10^{23}

atoms.

Rounded to two decimal places, this gives

2.41 \times 10^{23}

atoms.

Answer:

2.41 \times 10^{23}

atoms.

Go to Question:

Prev Question

Next Question