Topic 1 - Key Concepts in Chemistry

Question 1

What are the molecules on the right-hand side of a word equation called?

Answer 1

The products

Question 2

What are the molecules on the left-hand side of a word equation called?

Answer 2

The reactants

Question 3

What does (s) mean?

Answer 3

Solid

Question 4

What does (l) mean?

Answer 4

Liquid

Question 5

What does (g) mean?

Answer 5

Gas

Question 6

What does (aq) mean?

Answer 6

Aqueous (dissolved in water)

Question 7

What is the chemical formula of chlorine?

Answer 7

Cl₂

Question 8

What is the chemical formula of ammonia?

Answer 8

NH₃

Question 9

What is the ammonium ion’s formula?

Answer 9

NH₄+

Question 10

What is the nitrate ion’s formula?

Answer 10

NO₃ -

Question 11

What is the sulfate ion’s formula?

Answer 11

SO₄² -

The ion charge is 2-

Question 12

What is the hydroxide ion’s formula?

Answer 12

OH-

Question 13

What is the carbonate ion’s formula?

Answer 13

CO₃²-

The ion charge is 2-

Question 14

what is an ionic equation?

Answer 14

an equation when only the reacting particles (and the products they form are included). You can write an ionic equation for any reaction involving ions in solution.

Question 15

how do you write an ionic equation?

Answer 15

you write a balanced symbol equation and take out any aqueous ions which are present on both sides of the equation (they haven’t reacted or been changed.)

step 1: write the full balanced symbol equation

step 2: anything that’s ionic and aqueous will break up into its ions in solution so write the equation showing all the aqueous ions separately.

step 3: to get the ionic equation cross out anything which is the same on both sides of the equation (is the same and hasn’t reacted/been changed.)

step 4: write out the ionic equation without the ions you crossed out, the overall charge should be the same on both sides.