Law of Conservation of Mass
Ain’t Never Losing Dat Mass
Answer the word problems below using the LAW OF CONSERVATION OF MASS.
SHOW ALL WORK AND INCLUDE UNITS !!!! If confused about what something
is, ask google. You have the entire internet to help yourself. Praise be 八(＾□＾*)
1. Hydrogen and oxygen react chemically to form water. How much water would form if
14.8 grams of hydrogen reacted with 34.8 grams of oxygen? (H2 + O2 → H2O)
2. When ammonium nitrate (NH4NO3) explodes, the products are nitrogen, oxygen, and
water. When 40 grams of ammonium nitrate explode, 14 grams of nitrogen and 8
grams of oxygen form. How many grams of water form?
(NH4NO3 → N2 + O2 + H2O)
3. In an experiment, 63.5g of copper (Cu) combines with 16g of oxygen (O2) to form
cupric oxide. How many grams of cupric oxide (CuO)? (Cu + O2 → CuO )
4. A student combines 154 grams of carbon tetrachloride (CCl4) and an unknown
quantity of bromine (Br2) in a sealed container to produce 243 grams of
dibromochloromethane (CBr2Cl2) and 71 grams of chlorine (Cl2). How much
chlorine (Cl2) was used in the reaction, assuming the reactants are completely used
up?
CCl4 + Br2 → CBr2Cl2 + Cl2
5. ​A student asks why the ashes from a fire have a much lower mass than the wood
that was burned. Which is the correct answer to the student’s question?
a.Gases are released into the air.
b.Atoms in the wood are destroyed.
c.Heat causes molecules to lose density.
d.Water inside the wood solidifies.
6. Hydrogen and oxygen react chemically to form water. How much water would form if
14.8 grams of hydrogen reacted with 34.8 grams of oxygen?
(H2 + O2 → H2O)
7. When ammonium nitrate (NH4NO3.) explodes, the products are nitrogen, oxygen,
and water. When 40.0 grams of ammonium nitrate explode, 14.0 grams of nitrogen
and 8.0 grams of oxygen form. How many grams of water form?
(NH4N03 → N2 + O2 + H2O)