topic 4.0 substances undergo chemical change when iteracting

Question 0

Reactants

Answer 0

Materials that start a reaction

Ex. Wood and oxygen to start a fire

Question 1

Chemical reactions

Answer 1

When two or more substance combine to form new substances

Ex. Launching a space shuttle

Question 2

Products

Answer 2

New materials provided by the reaction of reactants

Ex. Carbon dioxide is given off a burning campfire also water and energy are released

Question 3

Word equations

Answer 3

In a word equation the reactants always appear to the left of the arrow and the products to the right
Ex. Wood+oxygen -> carbon dioxide+water+energy released

Question 4

Evidence of a chemical reaction

Answer 4

Colour change
Formation of a solid or has
Release or absorption of heat

Question 5

Exothermic reactions

Answer 5

Chemical reaction that releases heat energy

Ex. When you burn an object it gives off heat

Question 6

Endothermic reaction

Answer 6

Chemical reaction that absorbs heat energy

Ex. Chemical cold packs

Question 7

Combustion

Answer 7

A chemical reaction that occurs when oxygen reacts with a substance to form a new substance and give off energy
Ex. Fire

Question 8

Corrosion

Answer 8

A slow chemical change that occurs when oxygen in the air reacts with a metal
Ex. Rusting

Question 9

Cellular respiration

Answer 9

A chemical reaction that takes place in the cells in your body
Ex. Food reacts with oxygen to produce energy and CO2

Question 10

Writing chemical reactions into chemical equations

Answer 10

Use the chemicals and write their chemical name and ion charge
Use plus signs to show the adding of compounds and than wrote an arrow to show the product on the other end using its chemical name and ion charges as well

Question 11

Law of conservation of mass

Answer 11

In a chemical reaction, products are formed when the reactant/reactants undergoes a change. These products usually look different from the reactants. The total mass of the products is always the same as the total mass of the reactants. Matter is not creates or destroyed in a chemical reaction
Ex. Combining different amounts of chemicals to proclaimed a new substance using both of their chemical names and ion charges

Question 12

Closed system

Answer 12

Where no additional material is allowed to enter or leave

Ex. Hydraulics

Question 13

Open system

Answer 13

Where additional material is allowed to enter or leave

Ex. Air breaks

Question 14

Finding the amount real eased or the total added of chemicals

Answer 14

Add the amount of chemicals together and than subtract it from the final mass to find out how much of a substance was released
To find the product just simply add the amount of both chemicals together

Question 15

Four factors that can affect the rate if a chemical reaction

Answer 15

The presence of a catalyst
The concentration of the reactants
The temp of reactants
The surface area of reactants

Question 16

Catalysts

Answer 16

Substances that help a reaction proceed faster

They are present in the reactants of the reaction but are not consumed during their reaction

Question 17

Enzymes

Answer 17

Reactions such as breaking down food require a catalyst called an enzyme
Without enzymes many reactions would require higher temps- bad for the body!
Help get rid of poisons

Question 18

Catalase

Answer 18

Enzyme that is found in many animal and plant cells

Speeds up the break down of hydrogen peroxide into harmless water and oxygen

Question 19

Concentration

Answer 19

The greater the concentration if the reactants, the faster the reaction
Ex. Adding more aluminum to a cooper chloride solution will speed up the reaction

Question 20

Temperature

Answer 20

The more heat added to the reactants, the faster the reaction
Ex. The added heat causes the atoms of each reactant to move faster and collide

Question 21

Surface area

Answer 21

Increasing the S.A of the reactants will increase the rate of the reaction
Ex. The greater the S.A of the reactants means that more area is available for a reaction