Law of Conservation of Mass PowerPoint

Matter cannot be created or destroyed, it may be rearranged in space or changed into

different types of particles

So what happens to Mass?

Does the wood have the same mass after it burns?

Does the rusted door pulls have the same mass as they did when they were new?

Wood Burning

The weight of the wood diminishes but the wood is turned into carbon dioxide and waterthrough a chemical reaction.

So if you were able to collect the carbondioxide and water and add that to the left overwood the mass would equal the same as it did previous to the wood burning.

Wood not burning= carbon dioxide + water + left over wood

Iron Rusting

A piece of iron would increase its weight.This happens because of oxygen, water, and hydroxide have attached to the iron.

So if you were able to separate the iron,oxygen, water, and hydroxide before the rusting began the masses would equal the rusted iron

Iron + oxygen + water + hydroxide = Rusted iron

Did your weight of your reactants differ from your

solution?

+ + +

Calcium Chloride24 grams

Sodium Bicarbonate14 grams

Phenol Red25 grams

=

Water50 grams

According to the law of conservation, your final mixture should weigh 113 grams

How much would the left over wood weigh?

= + +

100 grams 25 grams 15 grams

Wood not burning= carbon dioxide + water + left over wood

Chemical Equations

Chemical equations are much like math equations. This means that both sides of the equation must be equal.

Chemical Equations

Balancing Equations_____ H2 + _____ O2 _____ H2O

_____ N2 +_____ H2 _____ NH3

_____ S8 + _____ O2 _____ SO3

_____ N2 + _____ O2 _____ N2O

_____ HgO _____ Hg + _____ O2

Energy in Chemical ReactionsWhat happens in a chemical reaction?

Energy is released or absorbed during a chemical reaction.

Where does this energy come from? Chemical bonds brea kand form when atoms gain,

lose, or share electrons When this happens, bonds break in the reactants

and new bonds are formed in the products.

Exothermic Reactions•Release thermal energy in various forms such as light and sound.

•The products are more stable, and their bonds have less energy than those of the reactants

Endothermic ReactionsReactions that absorb thermal energy.The reactants are more stable, and their

bonds have less than those of their products