Law of Conservation of Mass solved chemistry question

 ________REACTANT(S)_______ ——–>PRODUCT(S)

Magnesium        +               Oxygen ——> Magnesium Oxide

? g                        +                  20 g —–>              50 g

Based on the Law of Conservation of Mass, predict the minimum amount of magnesium that will react with all 20  grams of oxygen to produce 50 grams of magnesium oxide.

Solution

Law of Conservation of Mass = The sum of the masses of the reactants is equal to the sum of the masses of the products.

sum(reactants) = sum(products)

Magnesium        +               Oxygen ——> Magnesium Oxide

? g                        +                  20 g —–>              50 g

?+20=50

?=30 grams Magnesium

Law Of Conservation Of Mass Question With Solution

When ammonium nitrate (NH4NO3) explodes, the produsts are nitrogen, oxygen and water. When 40 grams of ammonium nitrade explode, 14 grams of nitrogen and 8 grams of oxygen form. How many grams of water form?  (NH4NO3 –> N2 + O2 + H2O)

Solution:

Law Of Conservation Of Mass: The sum of the masses of the reacting substances is equal to the sum of the masses of the products formed as a result of the reaction.

sum(reactants) = sum(products)

NH4NO3 ————> N2____ +____O2_____+____H2O

40_______________14____________8____________?

40 = 14+8+?

?= 18 grams H2O