Question

What mass of oxygen would form from 2.30 moles of water?

Answer 1

Answer : The mass of oxygen will be, 36.8 grams

Solution : Given,

Moles of water = 2.30 moles

Molar mass of $O_2$ = 32 g/mole

First we have to calculate the moles of oxygen.

The balanced chemical reaction will be,

$2H_2O\rightarrow 2H_2+O_2$

From the balanced reaction we conclude that

2 moles of water decomposes to give 1 mole of $O_2$

2.30 moles of water decomposes to give $\frac{2.3}{2}=1.15$ moles of $O_2$

Now we have to calculate the mass of oxygen.

$\text{Mass of }O_2=\text{Moles of }O_2\times \text{Molar mass of }O_2$

$\text{Mass of }O_2=(1.15moles)\times (32g/mole)=36.8g$

Therefore, the mass of oxygen will be, 36.8 grams