Question

solve the following problems according toconvert to moles1. $12.04 \times 10^{23}$ atoms he2. $3.01 \times 10^{23}$ atoms cu3. 100 atoms ar4. 1.0 atom s5. 24 grams c6. 59.3 grams sn

Explanation:

Step1: Use Avogadro's number ($6.02 \times 10^{23}$ atoms/mol) to convert atoms to moles.

Moles = $\frac{\text{Number of atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}}$

Step2: For mass to moles, use molar mass ($M$): Moles = $\frac{\text{Mass (g)}}{M\ \text{(g/mol)}}$

1. He atoms to moles

Moles of He = $\frac{12.04 \times 10^{23}\ \text{atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}} = 2.00\ \text{mol}$

2. Cu atoms to moles

Moles of Cu = $\frac{3.01 \times 10^{23}\ \text{atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}} = 0.500\ \text{mol}$

3. Ar atoms to moles

Moles of Ar = $\frac{100\ \text{atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}} \approx 1.66 \times 10^{-22}\ \text{mol}$

4. S atom to moles

Moles of S = $\frac{1.0\ \text{atom}}{6.02 \times 10^{23}\ \text{atoms/mol}} \approx 1.66 \times 10^{-24}\ \text{mol}$

5. C grams to moles (M of C = 12.01 g/mol)

Moles of C = $\frac{24\ \text{g}}{12.01\ \text{g/mol}} \approx 2.0\ \text{mol}$

6. Sn grams to moles (M of Sn = 118.71 g/mol)

Moles of Sn = $\frac{59.3\ \text{g}}{118.71\ \text{g/mol}} \approx 0.499\ \text{mol}$

Answer:

1. $2.00\ \text{mol He}$
2. $0.500\ \text{mol Cu}$
3. $1.66 \times 10^{-22}\ \text{mol Ar}$
4. $1.66 \times 10^{-24}\ \text{mol S}$
5. $2.0\ \text{mol C}$
6. $0.499\ \text{mol Sn}$