Question

Determine how many atoms of silver would be produced if 100 grams of copper reacts with an excess of silver nitrate?

Answer 1

Answer: -

2 x 10 ²⁴ atoms of Ag rounded off to 1 significant figures.

Explanation: -

Mass of Cu = 100 g

Molar mass of Cu = 63.55 g / mol

Number of moles of Cu = 100 g / (63.55 g/mol)

= 1.574 mol of Cu

The balanced chemical equation for the reaction is

Cu + 2AgNO₃ → Cu(NO₃)₂ + 2 Ag

From the balanced chemical equation we see

1 mol of Cu gives 2 moles of Ag

1.574 mol of Cu gives $\frac{2 moles of Ag x .574 mol of Cu}{1 mo of Cu}$

= 3.148 mol of Ag

1 mole of Ag has 6.02 x 10 ²³ atoms of Ag according to Avogadro's Law.

3.148 mol of Ag has $\frac{6.02 x 10 ²³ atoms of Ag x 3.148 mol of Ag}{1 mol of Ag}$

= 18.95 x 10²³ atoms of Ag

= 2 x 10 ²⁴ atoms of Ag rounded off to 1 significant figures.