Question

Use the problem below to answer the question: How many grams of H2 would be formed if 34 grams of carbon reacted with an unlimited amount of H2O? The reaction is C + H2O → CO + H2 What substance are we expected to solve for?

Answer 1

Answer : The mass of hydrogen gas $H_2$ will be, 5.6 grams.

Explanation : Given,

Mass of C = 34 g

Molar mass of C = 12 g/mole

Molar mass of $H_2$ = 2 g/mole

First we have to calculate the moles of carbon (C).

$\text{Moles of }C=\frac{\text{Mass of }C}{\text{Molar mass of }C}=\frac{34g}{12g/mole}=2.8moles$

Now we have to calculate the moles of $H_2$.

The balanced chemical reaction is,

$C+H_2O\rightarrow CO+H_2$

From the balanced reaction we conclude that

As, 1 mole of $C$ react to give 1 mole of $H_2$

So, 2.8 moles of $C$ react to give 2.8 moles of $H_2$

Now we have to calculate the mass of $H_2$.

$\text{Mass of }H_2=\text{Moles of }H_2\times \text{Molar mass of }H_2$

$\text{Mass of }H_2=(2.8mole)\times (2g/mole)=5.6g$

Therefore, the mass of hydrogen gas $H_2$ will be, 5.6 grams.

Answer 2

You have to find how many moles of H2 has formed.

C+ H2O -> CO + H2

mole of carbon reacted = mass / molar mass = 34g/ 12g per mol = 2.83 mol

for every 1 mole of carbon will form 1 mole of H2

mole of hydrogen produced = 1* 2.83 = 2.83 mol

mass of hydrogen = mole * molar mass = 2.83 mol * (1*2) = 5.66g