The freezing point of t-butanol is 25.50°C and is 9.1°C kg/mol. Usually t-butanol absorbs water on exposure to air. If the freezing point of a sample which contains 12.4 g of t-butanol is 24.56°C, how many grams of water are present in the sample?

Mass of water is smething that you froma drug test or sum girl ya

Exothermic,  physical change after it is already baked

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts