1. What does the Law of conservation of mass state? a. According to the Law of Conservation, what is true about the masses of the reactants and the products in a chemical reaction?
b. Find the missing mass in the reactions below:

MgO + H2O → Mg(OH)2
12.4 g ? 21.8

According to the law of conservation of mass, the mass of the products in a chemical reaction must equal the mass of the reactants. The law of conservation of mass is useful for a number of calculations and can be used to solve for unknown masses, such the amount of gas consumed or produced during a reaction.

weight of any object is given by

w = m*g

where m is mass of the object and g is the acceleration due to gravity.

for earth the value of g is 9.8 m/s^2 so

w=117.6 n m=12 g=?

117.6=12g => g=9.8 m/s^2

which is the force of gravity on earth.

the answers are

c and c