Initial test- ions etc.

Question 1

Write the formula for the ions: Lithium, Sodium, Caesium and Silver..

Answer 1

Lithium- Li+
Sodium- Na+
Caesium- Cs+
Silver- Ag+

Question 2

Name these ions:
Be2+, Zn2+, Pb2+ and Fe2+..

Answer 2

Beryllium, Zinc, Lead and Iron(II).

Question 3

Name the three 3+ common ions and their formulas.

Answer 3

Aluminium, Al3+
Iron(III), Fe3+
Chromium, Cr3+

Question 4

Write the formula for sulphate sulphite

Answer 4

Sulphate: SO4^2-
Sulphite: SO3^2-

Question 5

What is the formula for nitride and phosphide?

Answer 5

Nitride: N3-
Phosphide- P3-

Question 6

How many moles are in 15g of Calcium?

Answer 6

Ar of Calcium: 40.1 = 1 mole
40.1g= 1 mole
1g= 1/40.1
15g= 1/40.1 x 15
15g= 0.37 moles (2dp)

Question 7

What is the difference between empirical and molecular formula?

Answer 7

Molecular formulas tell you how many atoms of each element are in a compound, and empirical formulas tell you the simplest or most reduced ratio of elements in a compound.

Question 8

3.2 g of sulfur reacts with oxygen to produce 6.4 g of sulfur oxide. What is the formula of the oxide?

Answer 8

Step one:
write the masses of sulfur and oxygen: 3.2g of sulfur and 3.2g of oxygen.
Step two:
Ar of S= 32
Ar of O= 16
3.2/32= 0.1
3.2/16= 0.2
0.1/0.1= 1 SULFUR
0.2/0.1= 2 OXYGEN
answer= SO2

Question 9

How do you calculate the number of particles in a fixed mass?

Answer 9

Number of particles= Avogadro’s constant (6.02 × 1023) x amount of substance in mol

Question 10

Between what elements do covalent bonds form?

Answer 10

Covalent bonds form between 2 non metals and electrons are shared between the atoms making a strong bond between them.

Question 11

Between what elements do ionic bonds form?

Answer 11

Between and metal and a non-metal. The metal looses outer shell electrons and becomes a cation and the non-metals gain the electrons causing them to become anions.

Question 12

Between what elements do metallic bonds form?

Answer 12

Between two metals.

Question 13

Define the term atom.

Answer 13

The smallest particle of a chemical element which is the building block of all elements which exist.

Question 14

Define the term ion.

Answer 14

An atom or group of atoms which have a gained a negative or positive charge due to the loss or gain of electrons.

Question 15

Define the term molecule

Answer 15

A particle which contains two or more atoms chemically bonded together which has both chemical and physical properties.