Chemical Reactions
What is a sign that a chemical reaction has occurred?
Gas, light, temp, new substance, colour
What is a sign that a physical change has occured?
State or shape change
Two types of equations?
Word & Chemical/Symbol Equations
Is this equation balanced?
Fe2O3 + Al → Fe + Al2O3
Exothermic reactions are where energy in the form of heat is;
released
Definition of a chemical reaction?
Reaction where a new substance is formed.
Reaction where no new substance is formed.
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.
Basic principle for making sure that chemical equations and number of atoms are balanced?
Law of Conservation of Matter
Which of cell respiration or photosynthesis is endothermic?
Photosynthesis
List 3 examples of chemical reactions?
Various answers
3 examples of physical reactions?
Various answers.
s, l, g, aq
The numbers that we can add into equations at the start of chemical formulas are called?
Coefficients
In both endo and exothermic reactions, energy is taken in / released in the form of;
What are the new substances formed by a chemical reaction called?
Products
Process water goes through during three types of physical change?
Solid ice, melts to liquid water, evaporates to water vapour gas
Symbol equation for the following worded equation?
carbon monoxide + water -> carbon dioxide + hydrogen
CO + H2O -> CO2 + H
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
During an exothermic reaction the temperature of the surroundings;
Increases
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
List all 5 states of matter?
solid, liquid, gas, plasma, aqueous.
Two major things that symbol equations provide that word equations don't?
Number of atoms & states of matter
Balance this equation?
N2 + H2 -> NH3
N2 + 3H2 -> 2NH3
In terms of the rearrangement of new atoms, the two steps involved in this are to what?
1. Break bonds
2. Make new bonds