Question

How many grams of Cl2 are in 1.20 x 1024 Cl atoms?

Answer 1

70.906 g

Step-by-step explanation:

We are given;

• Atoms of Chlorine = 1.2 × 10^24 atoms

We are required to calculate the mass of Chlorine

• We know that 1 mole of an element contains atoms equivalent to the Avogadro's number, 6.022 × 10^23.
• That is , 1 mole of an element = 6.022 × 10^23 atoms

• Therefore; 1 mole of Chlorine = 6.022 × 10^23 atoms

But since Chlorine gas is a molecule;

• 1 mole of Chlorine gas = 2 × 6.022 × 10^23 atoms

But, molar mass of Chlorine gas = 70.906 g/mol

Then;

70.906 g Of chlorine gas = 2 × 6.022 × 10^23 atoms

= 1.20 × 10^24 atoms

Thus;

For 1.2 × 10^24 atoms ;

= ( 70.906 g/mol × 1.2 × 10^24 atoms ) ÷ (1.20 × 10^24 atoms)

= 70.906 g

Therefore, 1.20 × 10^24 atoms of chlorine contains a mass of 70.906 g

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