Question

Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react with 3 g of hydrogen gas .

Answer 1

The law of constant proportions states that chemical compounds are made up of elements that are present in fixed ratio by mass.

• $2{\mathrm{H}}_2+{\mathrm{O}}_2\to 2{\mathrm{H}}_2\mathrm{O}$
• Since ,1 mole i.e 32 g of oxygen reacts with 2 mole i.e 4 g of hydrogen.
• So, 3 g of ${\mathrm{H}}_2$require =$$\begin{gathered} \frac{3\times 32}{4} \\ =24gramsof{O}_2 \end{gathered}$$