Law of Conservation of Mass

IPC 8.C Investigate and Identify the Law of Conservation of Mass

A Chemical Reaction must be balanced.

A reaction equation shows the same number and kind of

atoms on both sides.

Reactants Products

      Al +       O2       Al2O3

http://richardbowles.tripod.com/chemistry/balance.htm

__N2 + __H2 __NH35 15 51 3 1

Law of Conservation of Mass:

The total mass of substances does not change during a chemical reaction.

reactant 1 + reactant 2

product

total mass total mass=

calcium oxide + carbon dioxide

calcium carbonate

CaO + CO2

CaCO

3

56.08g + 44.00g

100.08g

academic.evergreen.edu/curricular/matterandmotion/chem_phys%5Clectures%5Coct5.ppt –

?

If a gas is produced in a chemical reaction, it can be difficult to measure its mass if it escapes into the surroundings.

The illustrations show a conservation-of-mass

experiment. The solution in the beaker lost

mass because — A materials have less mass at

high temperatures B the mass of the reactants

and products was less than 100 g

C sodium sulfate (Na2SO4) is lighter than air

D some of the water molecules turned into gas

In the procedure shown above, a calcium chloride solution is mixed with a sodium sulfate solution to create the products shown. Which of the following is illustrated by this activity?

F The law of conservation of mass G The theory of thermal equilibrium H The law of conservation of momentum J The theory of covalent bonding

To produce 4 molecules of sugar, a plant needs —

A 6 molecules of hydrogen B 12 molecules of ATP C 18 molecules of water D 24 molecules of carbon dioxide

If one thing in an equation is changed, all other reactants and products must be changed by the same amount.

424CO2 24 H2O 24O2

Try all the answer choices to see which one works!

What are the coefficients that will balance this chemical equation?

A 2, 1, 1 B 3, 4, 2 C 2, 2, 1 D 4, 3, 2

2 1 1 No!3 4 2 No!2 2 1 YES!