Question

You are given a sample containing 0.40 moles of a substance.?. . a) How many atoms are in the sample if the substance is copper? . . b) How many atoms are in the sample if the substance is gold? . . c) How many molecules are present in the sample if the substance is acetone, CH3COCH3? .

Answer 1

Answer:

a) 2.4 × 10²³ atoms Cu; b) 2.4 × 10²³ atoms Au; 2.4 × 10²³ molecules acetone

Explanation:

There are Avogadro’s number of particles in one mole of those particles.

a) Cu

$\text{Atoms of Cu} = \text{0.40 mol Cu} \times \frac{ 6.022 \times 10^{23} \text{atoms Cu}}{\text{1 mol Cu}}= 2.4 \times 10^{23} \text{ atoms Cu}$

Thus, 0.40 mol of any particles contains 2.4 × 10²³ of those particles.

b) 0.40 mol Au = 2.4 × 10²³ atoms Au

c) 0.40 mol acetone = 2.4 × 10²³ molecules acetone