Question

If the density of ethanol, C2H5OH, is 0.789 g/mL. How many milliliters of ethanol are needed to produce 15.0 g of CO2 according to the following chemical equation?

C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)

Answer 1

C2H5OH(l) + 3 O2(g) → 2 CO2(g) + 3 H2O(l)

As per stoichiometry of the equation

1 mole of ethanol will give 2 moles of CO2 (2X44g)

Or we can say 88g of CO2 will be obtained from 1 mole of ethanol

So 15g will be obtained from 1X15 / 88 moles = 0.17 moles of ethanol

Now we will convert moles of ethanol to grams

1 mole is equal to 46g of ethanol

so 0.17 moles will be equal to 46 X 0.17 g = 7.82 grams

we can convert the grams to mL by followng formula

Density = mass / volume

so volume = 7.82 grams / 0.789 g / mL = 9.911 mL