Question

What mass of water can be obtained from 4.0 g of H2 and 16 g of O2?2 H2 + O2 ---> 2 H2O18 g36 g54 g9 g

Answer 1

18 grams of
`H_2O`

Step-by-step explanation:

The balanced equation of the reaction is:

`H_2+(1)/(2)O_2 -->H_2O`

From the balanced equation we can say 1 mole of H2 reacts with 0.5 moles of O2 to give one mole of H2O.

Number of moles of H2 =
`(Given\ mass)/(Molar\ mass)=(4)/(2)=2\ moles`

Number of moles of O2 =
`(Given\ mass)/(Molar\ mass)=(16)/(32)=0.5\ moles`

We have 2 moles H2 and 0.5 moles of O2.

Not all H2 reacts because the amount of O2 is limited.

Since only 0.5 moles of O2 is available only 1 mole of H2 reacts according to the balanced equation.

Hence 1 mole of H2O is formed which is 18 grams.

Answer 2

18 g is the mass produced by 4 g of H₂ and 16 g of O₂

Step-by-step explanation:

The reaction is:

2H₂ + O₂ → 2H₂O

So, let's find out the limiting reactant as we have both data from the reactants.

Mass / Molar mass = moles

4 g/ 2g/m = 2 moles H₂

16g / 32 g/m = 0.5 moles O₂

2 moles of hydrogen react with 1 mol of oxygen, but I have 0.5, so the O₂ is the limiting.

1 mol of O₂ produces 2 mol of water.

0.5 mol of O₂ produce (0.5 .2)/1 = 1 mol of water.

1 mol of water weighs 18 grams.