Question

What two liquids when mixed occupy less combined volume than the sum of their individual volumes (at room temp, sea-level pressure)? I've heard that mixing 1 unit volume of water with one unit volume of antifreeze occupies less than 2 units of combined volume. Is this true? What is the shrinkage?

Answer 1

yes this is true in many cases as when you mix two liquids specially water and antifreeze like ethylene glycol(EGW) , the volume generally shrinks.

ofcourse both liquids should be polar then it will happen very obiously .

let see how it happens:

as liquid also is a state of matter. and matter cosists of small molecules and there is lot of space between two molecules within matter. also these molecules are in random motion constantly. so when we mix two liquids with different molecular space. the antifreeze molecule slips into space between water molcules so it results into reduced volume. also if both liquid are polar then there is hydrogen bonding betwwen both types of molecules so total volume is less than 2 units.