Chem Reactions Revision 1

Chemical Reactions

100

What is a sign that a chemical reaction has occurred?

Gas, light, temp, new substance, colour

200

Definition of a chemical reaction?

Reaction where a new substance is formed. 

300

List 3 examples of chemical reactions?

Various answers

400

What are the new substances formed by a chemical reaction called?

Products

500

Rust is a chemical compound called iron oxide. It forms very slowly as iron reacts with oxygen and water.

What are the reactants?

Iron, oxygen, water

Physical Reactions

100

What is a sign that a physical change has occured?

State or shape change

200

Definition of a physical reaction?

Reaction where no new substance is formed.

300

3 examples of physical reactions?

Various answers. 

400

Process water goes through during three types of physical change?

Solid ice, melts to liquid water, evaporates to water vapour gas

500

List all 5 states of matter?

solid, liquid, gas, plasma, aqueous. 

Equations

100

Two types of equations?

Word & Chemical/Symbol Equations

200

Compounds in a reaction on the left side of the arrow are the ________, on the right side of the arrow they are called the ________. 

Reactants, products.

300

The four state symbols to put in chemical equations?

s, l, g, aq

400

Symbol equation for the following worded equation?

carbon monoxide + water -> carbon dioxide + hydrogen

CO + H₂O -> CO₂ + H

500

Two major things that symbol equations provide that word equations don't?

Number of atoms & states of matter

Balancing Equations

100

Is this equation balanced?

Fe₂O₃ + Al → Fe + Al₂O₃

200

Basic principle for making sure that chemical equations and number of atoms are balanced?

Law of Conservation of Matter

300

The numbers that we can add into equations at the start of chemical formulas are called?

Coefficients

400

How many potassium, oxygen and hydrogen atoms, respectively, there are on the product side. 

2 K (s) + 2 H2O (l) → 2 KOH (aq) + H2 (g)

2, 2, 4

500

Balance this equation?

N₂ + H₂ -> NH₃

N₂ + 3H₂ -> 2NH₃

Endothermic vs Exothermic

100

Exothermic reactions are where energy in the form of heat is; 

released

200

Which of cell respiration or photosynthesis is endothermic?

Photosynthesis

300

In both endo and exothermic reactions, energy is taken in / released in the form of;

Heat

400

During an exothermic reaction the temperature of the surroundings;

Increases

500

In terms of the rearrangement of new atoms, the two steps involved in this are to what?

1. Break bonds

2. Make new bonds