Question

Calculate the amount of water produced by the combustion of 8g of methane.

Answer 1

To solve such questions you must write a balanced reaction first.

CH4 (g)+2O2 (g)————-> CO2 (g) +2H2O (g)

Now according to the reaction 1 mole of CH4 gives 2 moles of H2O

And 16 grams of Methane mean 1 mole (moles=given mass/molecular mass. Molecular mass of methane is 16)

so 1 mole of methane = 16/16 (given mass 16 and molecular mass 16)

since 1 mole of methane is getting used up to form 2 mole of water.

number of moles=given mass/molecular mass ——- eq. 1

molecular mass of water is 18.

2=x/18 ( where x is the mass of water produced , using equation 1)

2*18=36grams

so 36 grams of water will be produced.

do it in this way or by taking 8g in the above it is for 16 g

or else

Methane is CH4.

CH4 —-> (o2) heat —-> CO2 + 2H2O

CH4 Mole weight = 16

water = 18

One mole of CH4 produce Two mole of water as per above equation.

Hence 16 gram Methane do produce 32 gram water and 44 gram CO2.

like this by taking 8g

Answer 2

Methane is CH4.

CH4 —-> (o2) heat —-> CO2 + 2H2O.

CH4 Mole weight = 16.

water = 18.

One mole of CH4 produce Two mole of water as per above equation.

Hence 16 gram Methane do produce 32 gram water and 44 gram CO2