10. Concepts in Chemistry: Equations

Question 1

What do Symbol Chemical Equations show?

Answer 1

They show the atoms on both sides

Question 2

What are Symbol Equations and an example?

Answer 2

Chemical changes in shorthand symbols or formulas of reactants and products

Need to be balanced ie same number of atoms on both sides of the equation

Balance the equation by putting numbers in front

E.g. H2SO4 + 2NaOH —> Na2SO4 + 2H2O

Question 3

What are State Symbols?

Answer 3

State of a substance in an equation

Solid = (s)
Liquid = (l)
Gas = (g)
Aqueous = (aq) - dissolved in water

Question 4

What are the Formuilas for 6 simple compounds - Molecules?

Answer 4

1) Water H20
2) Carbon dioxide C02
3) Chlorine Cl2
4) Ammonia NH3
5) Hydrogen H2
6) Oxygen O2

Question 5

What are the formulas for 5 Ions?

Answer 5

Ions form when atoms or groups of atoms gain or loose electrons to form charged particles

1) Ammonium NH4+
2) Nitrate NO3-
3) Sulfate SO42-
4) Hydroxide OH-
5) Carbonate CO3 2-

Question 6

What do Ionic Equations show?

Answer 6

Show just the useful bits of reactions

Only reacting particles and the products they form are included

Look at the balanced symbol equation and remove any aqueous ions that are present on both sides of the equation

Example on page 76 in textbook

Question 7

What is an example of a written equation?

Answer 7

Methane + Oxygen -> carbon dioxide + water

Methane buns in oxygen giving off carbon dioxide and water