Question

In the equation:2H2 + O2 → 2H2O100 molecules of hydrogen react with ........... molecules of oxygen.

Answer 1

Answer:

$50\text{ molecules}$

Explanation:

Here, we want to know the number of molecules of oxygen that was reacted with

From the question, we can see that the mole ratio is 2 to 1

Thus, the number of molecules of oxygen reacted will be half that of hydrogen

Hence, the number of molecules of oxygen will be:

$\rightarrow\frac{100}{2}\text{ = 50 molecules}$