Science Sturm

Reactants

The substances undergoing a chemical change

Products

The new substances formed

________----->________

Reactants ----->Products

Chemical Equation

A representation of a chemical reaction in which the reactants and products are expressed as formulas

The law of conservation of mass states that mass is

neither created or destroyed in a chemical reaction.

In order to show that mass is conserved during a reaction...

The chemical formula has to be balanced

Coefficients

The numbers that appear before the chemical formula

A balanced equation shows?

That mass is conserved/equal sides

You can balance a chemical equation by?

Changing coefficients not subscripts

Chemical Energy

Energy that is stored in chemical bonds of compounds

Chemical Reactions

Involves breaking of chemical bonds with the reactants and the formation of chemical bonds in products

Forming bonds

The formation of bonds releases energy.

Exothermic

A release of energy to the surrounding area. Energy released is greater than the energy needed

Endothermic

A reaction that absorbs energy from the surrounding area

Conservation of Energy

States that energy cannot be created or destroyed, but can be changed from one form to another

Reaction Rate

The rate of time for reactants to turn into products. Tells us how fast a reaction is going

Temperature

Increase in temperature will increase reaction rates. Fast moving particles are more likely to collide with each other

Surface Area

Greater surface area increase reaction rate. Increased in surface area provides greater exposure for reactants to collide

Stirring

Collisions are more likely to happen by this so reaction rates would increase

Concentration

The more reacting particles provides a greater chance for collisions. This would increase reaction rates

Catalysts

A substance that affects the reaction rate with out being used up in the reaction

Equilibrium

The forward and reverse paths remain at the same rate

When a physical change does not go to completion...

Equilibrium is established between forward and reverse changes

Mole

Is an amount of a substance that contains approximately 6.0x10/23 particles of that substance

Molar Mass

The mass of one mole of a substance

Factors that effect the reaction rate

temperature, surface area, concentration, stirring, and catalysts