Question

What mass of H2 is needed to react with 8.75 g of O2 according to the following equation: O2(g) + H2(g) → H2O(g)?

Answer 1

Answer:- B: $1.10g H_2$ is the right answer.

Solution:- The balanced equation is:

$O_2(g)+2H_2(g)\rightarrow 2H_2O(g)$

We have been given with 8.75 grams of oxygen and asked to calculate the grams of hydrogen needed to react with given grams of oxygen according to the balanced equation.

From balanced equation, 1 mole of oxygen reacts with 2 moles of hydrogen.

So, let's convert grams of oxygen to moles and multiply it by the mole ratio to calculate the moles of hydrogen that are easily converted to grams on multiplying by it's molar mass.

The complete set up looks as:

$8.75g O_2(\frac{1mole}{32g})(\frac{2mole H_2}{1mole O_2})(\frac{2.02g}{1mole})$

= $1.10g H_2$

Hence, the right option is B: $1.10g H_2$ .

Answer 2

Answer:

1.10 g H2

Explanation:

I took the test and got it right.