Question

A certain alcoholic beverage contains only ethanol (C₂H₆O) and water. When a sample of this beverage undergoes combustion, the ethanol burns but the water simply evaporates and is collected along with the water produced by combustion. The combustion reaction is C₂H₆O(l)+3O₂(g)→2CO₂(g)+3H₂O(g) When a 10.12 g sample of this beverage is burned, 11.59 g of water is collected.What is the mass in grams of ethanol in the original sample?Express your answer using two decimal places.What is the mass of water in the original sample?Express your answer using two decimal places.

Answer 1

The mass of ethanol = 9.89g

The mass of water = 0.23g

Step-by-step explanation:

Step 1: Given data

The beverage, has a mass of 10.12g, and contains ethanol + water.

When this beverage is burned, 11.59g of water is collected.

The combustion of this beverage is shown with following balanced equation:

C₂H₆O(l)+3O₂(g)→2CO₂(g)+3H₂O(g)

Here we can see that for 1 mole C2H6O consumed, there is produced 2 moles of CO2 and 3 moles of H2O.

Step 2: Calculate moles

moles water = mass of water/ molar mass water

moles water = 11.59 / 18 = 0.64389 moles

For 3 moles H2O produced, there is 1 mole of C2H6O consumed.

If there is 0.64389 moles of H20 produced, there is 0.2146 moles of C2H6O consumed.

Since ethanol is fully consumed, this means there was 0.2146 moles.

Step 3: Calculate mass of ethanol

mass ethanol = moles ethanol * Molar mass ethanol

mass of ethanol = 0.2146 moles * 46.07 g/mol = 9.887 g

The total beverage has a mass of 10.12g

11.59 - 9.887 = 0.233g

The mass of ethanol = 9.89g

The mass of water = 0.23g