The heat of combustion of ethanol into carbon dioxide and water is – 327 kcal at constant pressure. The heat evolved (in cal) at constant volume and 27^oC (if all gases behave ideally) is (R = 2 cal mol^–1 K^–1) ________.

The correct observation in the following reactions is :

The major product of the following reaction is :

The shape / structure of [XeF₅]^– and XeO₃F₂, respectively, are