MHT CET · Chemistry · Some Basic Concepts of Chemistry
What is the percentage by mass of oxygen in NaOH ? (Atomic mass of \(\mathrm{Na}=23 \mathrm{u}, \mathrm{O}=16 \mathrm{u}, \mathrm{H}=1 \mathrm{u}\) )
- A 16
- B 20
- C 40
- D 60
Answer & Solution
Correct Answer
(C) 40
Step-by-step Solution
Detailed explanation
\(\% \mathrm{O} \text { by mass } =\frac{\text { Atomic weight of oxygen }}{\text { Molecular weight of } \mathrm{NaOH}} \times 100 \)
\(\therefore\) \(=\frac{16}{40} \times 100=40 \%\)
\(\therefore\) \(=\frac{16}{40} \times 100=40 \%\)
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