Question

1. what is the % composition of cl and in nacl?

% composition = atomic mass of the component element x no. of atoms x 100% / molar mass of compound

1. what is the % composition of cl and in kcl?

% composition = atomic mass of the component element x no. of atoms x 100% / molar mass of compound

1. which compound has higher % cl? why? kcl or nacl because

Explanation:

Step1: Calculate molar mass of NaCl

The atomic mass of Na is approximately 22.99 g/mol and Cl is approximately 35.45 g/mol. Molar mass of NaCl ($M_{NaCl}$) = 22.99 + 35.45=58.44 g/mol.

Step2: Calculate % composition of Cl in NaCl

Using the formula $\%$ Composition = $\frac{\text{atomic mass of the component element}\times\text{No. of atoms}}{\text{Molar mass of compound}}\times100\%$. For Cl in NaCl, $\%$ Cl in NaCl = $\frac{35.45\times1}{58.44}\times100\%\approx60.66\%$.

Step3: Calculate molar mass of KCl

The atomic mass of K is approximately 39.10 g/mol and Cl is 35.45 g/mol. Molar mass of KCl ($M_{KCl}$)=39.10 + 35.45 = 74.55 g/mol.

Step4: Calculate % composition of Cl in KCl

Using the formula $\%$ Composition = $\frac{\text{atomic mass of the component element}\times\text{No. of atoms}}{\text{Molar mass of compound}}\times100\%$. For Cl in KCl, $\%$ Cl in KCl=$\frac{35.45\times1}{74.55}\times100\%\approx47.55\%$.

Step5: Compare % composition of Cl in NaCl and KCl

Since 60.66%>47.55%, NaCl has a higher percentage - composition of Cl. The reason is that the molar mass of Na is less than that of K, and when calculating the percentage - composition of Cl, the denominator (molar mass of the compound) is smaller for NaCl while the numerator (atomic mass of Cl) is the same in both cases.

Answer:

1. $\%$ Cl in NaCl $\approx$ 60.66%
2. $\%$ Cl in KCl $\approx$ 47.55%
3. NaCl has a higher % Cl because the molar mass of Na is less than that of K, resulting in a smaller molar - mass of NaCl compared to KCl while the atomic mass of Cl is the same in both compounds.