Calculation based on percent composition — lesson. Science State Board, Class 10.

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I. Calculate the percentage of \(S\) in \(H_2SO_4\).

Data:

Atomic mass of \(H=1\)

Atomic mass of \(S=32\)

Atomic mass of \(O=16\)

Solution:

\begin{array}{l} Molecular mass of H_{2} {SO}_{4} & = & (2 \times 1) + (1 \times 32) + (4 \times 16) \\ = & 2 + 32 + 64 \\ = & 98 g \end{array}

\begin{array}{l} % of S in H_{2} {SO}_{4} & = & \frac{Mass of sulphur}{Molecular mass of H_{2} {SO}_{4}} \times 100 \\ = & \frac{32}{98} \times 100 \\ = & 32.65 % \end{array}

Therefore, the percentage of \(S\) in \(H_2SO_4=32.65%\)

II. Calculate the percentage of \(O\) in \(H_2SO_4\).

Data:

Atomic mass of \(H=1\)

Atomic mass of \(S=32\)

Atomic mass of \(O=16\)

Solution:

\begin{array}{l} Molecular mass of H_{2} {SO}_{4} & = & (2 \times 1) + (1 \times 32) + (4 \times 16) \\ = & 2 + 32 + 64 \\ = & 98 g \end{array}

\begin{array}{l} % of O in H_{2} {SO}_{4} & = & \frac{Mass of oxygen}{Molecular mass of H_{2} {SO}_{4}} \times 100 \\ = & \frac{16}{98} \times 100 \\ = & 16. 32 % \end{array}

Therefore, the percentage of \(O\) in \(H_2SO_4=16.32%\)

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12. Calculation based on percent composition