Question

state the type of change in the following examples and give 1 reason each:
liquefaction of carbon dioxide-
souring of milk-

Answer 1

1: liquefaction of carbon dioxide is a physical change since no new substance is formed .... and in chemical change a new substance is formed . therefore we conclude that liquefaction of CO₂ is a physical change...
2: souring of milk is a chemical change because it results in the production of sour - tasting lactic acid ...
    i hope that my answer will help u......................................^_^

Answer 2

1. physical - there is change of state of matter, no new substance formed, can be reversed.

2. chemical - there is a change in substance, a new substance is formed, cant be reversed.