Question

How much water can be produced when 18 grams of pentane is burned in air? C5H12 + 8 02 --> 5 CO2 + 6 H2O. 9.0 g 18 g 27 g 36 g 729

Answer 1

Answer: The mass of water produced is 27 g

Step-by-step explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}` ......(1)

Given mass of pentane = 18 g

Molar mass of pentane = 72.15 g/mol

Plugging values in equation 1:

`\text{Moles of pentane}=(18g)/(72.15g/mol)=0.250 mol`

The given chemical equation follows:

`C_5H_(12)+8O_2\rightarrow 5CO_2+6H_2O`

By the stoichiometry of the reaction:

If 1 mole of pentane produces 6 moles of water

So, 0.250 moles of pentane will produce =
`(6)/(1)* 0.250=1.5mol` of water

Molar mass of water = 18 g/mol

Plugging values in equation 1:

`\text{Mass of water}=(1.5mol* 18g/mol)=27g`

Hence, the mass of water produced is 27 g