C2: Fundamental Ideas (2)

Question 1

Ions

Answer 1

A charged particle produced by the loss/gain of electrons.

Question 2

What sort of ions do metals form?

Answer 2

Positively charged ones.
(atoms lose electrons)

Question 3

What sort of ions to non-metals form?

Answer 3

Negatively charged ones.
(atoms gain electrons)

Question 4

Ionic Bonds

Answer 4

The electrostatic force of attraction between positively and negatively charged ions.

Question 5

Relative Atomic Mass

Answer 5

The average mass of the atoms of an element compared with carbon 12.

Question 6

Relative Formula Mass

Answer 6

The total of the relative atomic masses, added up in the ratio of the chemical formula of a substance.

Question 7

Mole

Answer 7

The amount of substance in the relative atomic or formula mass in grams.

Question 8

No of Moles =

Answer 8

Mass (g) / Ar or Mr

Question 9

To calculate the percentage of an element in a compound:

Answer 9

> Work out the Mr of your compound, writing down the Ar of each element separately as you go.
Divide the Ar of your element by the total Mr of the compound.
x 100

Question 10

To find an empirical formula:

Answer 10

> Divide the amount of each element by its Ar.
Put what you get into a ratio.
Divide all of them by the smallest no. in the ratio.
Make a formula.

Question 11

Total Mass of Products =

Answer 11

Total Mass of Reactants

Question 12

Aqueous Solutions

Answer 12

Mixture made by adding a soluble substance to water.

Question 13

Litmus + Acid

Answer 13

Red

Question 14

Litmus + Alkali

Answer 14

Blue

Question 15

Percentage yield of a chemical reaction =

Answer 15

amount of product produced/ maximum amount of product possible (x100)

Question 16

Why might a percentage yield be less than it should be?

Answer 16

> Reaction might be reversible
May have given unexpected products in alternative reactions.
Some might be lost whilst handling apparatus.
Lost during separation from reaction mixture.