Question

When 100cm³ of distilled water at 20°C is mixed with 100cm³ of pure ethanol at 20°C, the resultant mixture has a volume of only 193cm³​

Give reason why this is so.

Answer 1

See Explanation

Step-by-step explanation:

If we look at the question closely, we will notice that 100cm³ of distilled water and 100cm³ of pure ethanol were mixed with both solutions at a temperature of 20°C. The resulting solution was found to occupy only 193cm³ instead of 200cm³​.

The reason for this is the great degree of intermolecular hydrogen bonding between ethanol and water molecules. This causes the molecules to draw closer and stick around each other causing the volume of the solution to reduce as observed above.