yes, the law of conservation of mass hold true in this case burning magnesium strip is explained by this equation 2 Mg (s) + O2 (g) -> MgO (s)So the lighter magnesium, after reacting with oxygen in air, forms the heavier magnesium oxide. molar mass of magnesium and magnesium oxide are 24g and 40g respectively. So the same ratio 24:40 (i.e. 3:5) is maintained in the given masses of 48g and 80g, which means mass is conserved in the reacion.
Yes, because when burning the magnesium strip the surrounding air also interacted and combined with it. In the experiment the final product weighs 80 grams, so you would subtract 80 – 48 leaving you with 32 grams. So the total mass of air that was added was 32 grams.
