Question

1. what is the % h in ca(c₂h₃o₂)₂?
2. what is the % ba in ba(no₃)₂?

Explanation:

Step1: Find molar mass of $\text{Ca(C}_2\text{H}_3\text{O}_2\text{)}_2$

First, get atomic masses: $\text{Ca}=40.08$, $\text{C}=12.01$, $\text{H}=1.008$, $\text{O}=16.00$.
Molar mass = $40.08 + 2\times(2\times12.01 + 3\times1.008 + 2\times16.00)$
$= 40.08 + 2\times(24.02 + 3.024 + 32.00)$
$= 40.08 + 2\times59.044 = 40.08 + 118.088 = 158.168\ \text{g/mol}$

Step2: Calculate total mass of H

Total H mass = $6\times1.008 = 6.048\ \text{g/mol}$

Step3: Find % H in $\text{Ca(C}_2\text{H}_3\text{O}_2\text{)}_2$

$\% \text{H} = \frac{\text{Total H mass}}{\text{Molar mass of compound}} \times 100$
$\% \text{H} = \frac{6.048}{158.168} \times 100 \approx 3.82\%$
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Step4: Find molar mass of $\text{Ba(NO}_3\text{)}_2$

Atomic masses: $\text{Ba}=137.33$, $\text{N}=14.01$, $\text{O}=16.00$.
Molar mass = $137.33 + 2\times(14.01 + 3\times16.00)$
$= 137.33 + 2\times(14.01 + 48.00)$
$= 137.33 + 2\times62.01 = 137.33 + 124.02 = 261.35\ \text{g/mol}$

Step5: Calculate total mass of Ba

Total Ba mass = $137.33\ \text{g/mol}$

Step6: Find % Ba in $\text{Ba(NO}_3\text{)}_2$

$\% \text{Ba} = \frac{\text{Total Ba mass}}{\text{Molar mass of compound}} \times 100$
$\% \text{Ba} = \frac{137.33}{261.35} \times 100 \approx 52.55\%$

Answer:

1. The percentage of H in $\text{Ca(C}_2\text{H}_3\text{O}_2\text{)}_2$ is approximately 3.82%
2. The percentage of Ba in $\text{Ba(NO}_3\text{)}_2$ is approximately 52.55%