Do mixtures have a set composistion

Remember to use the proper number of significant figures and leading zeros in all calculations.gelatin has a density of 1.27 g/cm³. if you have a blob of gelatin dessert that fills a 2.0 liter bottle, what is its mass? 2540 g2500 g3.9 x 10-43.937x 10-4

Astudent reacts 13 moles of iron with 21 moles of oxygen according to the following equation:

How many moles are contained in 5.6 l of h2 at stp