Question

solve the following problems according to the directions. show all work for full credit.
convert to moles

1. $12.04 \times 10^{23}$ atoms he
2. $3.01 \times 10^{23}$ atoms cu
3. 100 atoms ar
4. 1.0 atom s
5. 24 grams c
6. 59.3 grams sn
7. 5000. grams k
8. 0.00500 grams ne

convert to mass in grams

1. 10.0 moles na
2. 2.20 moles sn
3. 5.00 moles ag
4. $1.00 \times 10^{7}$ moles b
5. $6.02 \times 10^{23}$ atoms ca
6. $1.204 \times 10^{23}$ atoms bi

Explanation:

Convert to moles

Step1: Moles from atoms (Sn)

Use $\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}$
$\text{Moles of Sn} = \frac{59.3\ \text{g}}{118.71\ \text{g/mol}}$

Step2: Calculate Sn moles

Compute the division
$\text{Moles of Sn} = 0.500\ \text{mol}$

Step3: Moles from mass (K)

Use $\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}$
$\text{Moles of K} = \frac{5000.\ \text{g}}{39.10\ \text{g/mol}}$

Step4: Calculate K moles

Compute the division
$\text{Moles of K} = 128\ \text{mol}$

Step5: Moles from mass (Ne)

Use $\text{Moles} = \frac{\text{Mass}}{\text{Molar Mass}}$
$\text{Moles of Ne} = \frac{0.00500\ \text{g}}{20.18\ \text{g/mol}}$

Step6: Calculate Ne moles

Compute the division
$\text{Moles of Ne} = 2.48 \times 10^{-4}\ \text{mol}$

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Convert to mass in grams

Step7: Mass from moles (Na)

Use $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of Na} = 10.0\ \text{mol} \times 22.99\ \text{g/mol}$

Step8: Calculate Na mass

Compute the multiplication
$\text{Mass of Na} = 230.\ \text{g}$

Step9: Mass from moles (Sn)

Use $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of Sn} = 2.20\ \text{mol} \times 118.71\ \text{g/mol}$

Step10: Calculate Sn mass

Compute the multiplication
$\text{Mass of Sn} = 261\ \text{g}$

Step11: Mass from moles (Ag)

Use $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of Ag} = 5.00\ \text{mol} \times 107.87\ \text{g/mol}$

Step12: Calculate Ag mass

Compute the multiplication
$\text{Mass of Ag} = 539\ \text{g}$

Step13: Mass from moles (B)

Use $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of B} = 1.00 \times 10^7\ \text{mol} \times 10.81\ \text{g/mol}$

Step14: Calculate B mass

Compute the multiplication
$\text{Mass of B} = 1.08 \times 10^8\ \text{g}$

Step15: Mass from atoms (Ca)

First convert atoms to moles: $\text{Moles} = \frac{\text{Atoms}}{N_A}$, then $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of Ca} = \frac{6.02 \times 10^{23}\ \text{atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}} \times 40.08\ \text{g/mol}$

Step16: Calculate Ca mass

Simplify and compute
$\text{Mass of Ca} = 40.1\ \text{g}$

Step17: Mass from atoms (Bi)

First convert atoms to moles: $\text{Moles} = \frac{\text{Atoms}}{N_A}$, then $\text{Mass} = \text{Moles} \times \text{Molar Mass}$
$\text{Mass of Bi} = \frac{1.204 \times 10^{23}\ \text{atoms}}{6.02 \times 10^{23}\ \text{atoms/mol}} \times 208.98\ \text{g/mol}$

Step18: Calculate Bi mass

Simplify and compute
$\text{Mass of Bi} = 41.8\ \text{g}$

Answer:

Convert to moles

1. $0.500\ \text{mol Sn}$
2. $128\ \text{mol K}$
3. $2.48 \times 10^{-4}\ \text{mol Ne}$

Convert to mass in grams

1. $230.\ \text{g Na}$
2. $261\ \text{g Sn}$
3. $539\ \text{g Ag}$
4. $1.08 \times 10^8\ \text{g B}$
5. $40.1\ \text{g Ca}$
6. $41.8\ \text{g Bi}$