Why doesn't the paper burn in case 1 whereas it does in case 2? [3 MARKS]
Explanation of Each Case : 1.5 Mark
In case 1, as the paper is heated, water absorbs the heat from paper. Thus, paper doesn’t reach the ignition temperature and does not burn.
In case 2, there is no water, hence all the heat provided to the paper increases its temperature to such an extent that it exceeds the ignition temperature and eventually catches fire.