Why add 50cm3 of water and 50cm3 of alcohol it would not add up to 100cm3 of liquid?

Answer 1

There are several possible reasons:

1. Inaccuracy in measurement in the smaller amounts could give rise to a combined apparent error in the larger amount
2. Some trace amounts of fluid may be left behind in the beakers that were used to measure the fluid
3. If the two fluids are not the same temperature, there could by a small amount of thermal expansion/contraction when the fluids are mixed
4. Some fluid could be lost to evaporation, especially true of alcohol

Answer 2

If we take 50 ml of two different liquids and mix them they will not always add up to 100 ml. The mixture will be 100 ml only when the chosen liquids don't mix with each other at all, somewhat as in case of oil and water mix.

Alcohol does mix well with the water and therefore the final mixture will have a volume less than 100 ml. At molecular level this happens because molecules of alcohol can fit well between water molecules (compared to molecules of oil between water), thus occupying less overall space, resulting in a smaller volume.

Answer 3

It is because the particles of the water are smaller than the alcohol particles so the water particles can fit between the alcohol.

Another way to explain it would be

Imagine a box filled with footballs, there would be spaces between them well if you poured Golf balls into them they would fill the spaces but still fit into the same size of box!)

Answer 4

Because of forming hydrogen bonds between water and alcohol they will have less volume.

Answer 5

95cm3