Question

using the equation 2H2+O2-->2H2O if 19g of oxygen reacts completely, how many grams of hydrogen must react with it

Answer 1

Answer: 2.4 grams

Step-by-step explanation:

To calculate the moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}`

For
`O_2`

Given mass = 19 g

Molar mass of
`O_2` = 32 g/mol

Putting values in above equation, we get:

`\text{Moles of}O_2=(19)/(32)=0.60moles`

`2H_2+O_2\rightarrow 2H_2O`

1 mole of
`O_2` reacts with 2 moles of
`H_2`

0.60 moles of
`O_2` wil react with =
`(2)/(1)* 0.60=1.20` moles of
`H_2`

mass of
`H_2=moles* {\text {molar mass}}=1.20moles* 2g/mol=2.4g`

Thus 2.4 grams of hydrogen will react completely with 19 g of oxygen.

Answer 2

Hello!

For this reaction: 2H₂ + O₂ → 2H₂O

If 19 g of oxygen reacts completely, you'll need 2,39 g of H₂

To calculate that, you need to use the following conversion factor, applying molar equivalences, reaction coefficients, and molar masses, to go from grams of Oxygen to grams of Hydrogen:


`H_(2) Mass=19g O_(2)* (1 mol O_(2))/(31,9988gO_(2))* (2 mol H_(2))/(1 mol O_(2))* (2,01588 gH_(2))/(1 mol H_(2)) =2,39gH_(2)`