Unit3- Quantative chemistry

Question 1

What is the conservation of mass theory

Answer 1

The total amount of the product is equal to the total mass of the reactants

Question 2

Why must we balance equations

Answer 2

To make sure the reactant mass and product mass are the same because no atoms are gained or lost in a reaction

Question 3

Ionic compounds form when metals react with what

Answer 3

Non metals

Question 4

Metals form ? Ions

Most non metals form ? Ions

Answer 4

Metals form positive ions

Most non-metals form negative ions

Question 5

How do you work out how many ions metals form?

What doesnt this apply to

Answer 5

Note which group they are in for example Magnesium is in group 2, therefore forms 2+ ions

This doesnt apply to the transition metals

Question 6

How many ions do group 6 metals lose

How many ions do group 7 metals lose

Answer 6

Group 6 lose -2

Group 7 lose -1

Question 7

What are the two non metals that have a positive charge

Answer 7

Hydrogen+

Ammonium +

Question 8

In ionic compounds the charges on the ions have to cancel out to leave ?

Answer 8

An overall charge of 0

Question 9

What do ionic compounds leave out?

Answer 9

Spectator ions

Question 10

How would you write

Magnesium nitrate
Mg2+ NO3 -

Answer 10

Mg(NO3)2

Question 11

Percentage by mass= ?/? X100

Answer 11

Mass of element / total relative formula mass of a compound

X100

Question 12

What is a mole

Answer 12

A measure of the amount of particles in a substance

Question 13

One mole of any substance contains the same number of particles. What is this amount? What is it called?

Answer 13

6.02 x 10 to the 23

Avogadro constant

Question 14

The mass of one mole of a substance is its?

Answer 14

Its relative atomic mass or relative formula mass in Grams

Question 15

Number of moles= ?/?

Answer 15

Mass of a substance in g / atomic (or formula) mass in g/mol

Question 16

What is the relative atomic mass symbol

Answer 16

Ar

Question 17

How do you balance an equation using moles

Answer 17

Work out the amount of moles in each compound, divide by the smallest mole amount, then put it onto the og equation

Question 18

What is a limiting reactant and excess

Answer 18

When two chemicals react together, one chemical is completely used up during the reaction.
Once one chemical is used up, it stops the reaction going any further. This is the limiting reactant. The other is said to be in excess

Question 19

What is the concentration of a solution

Answer 19

The mass of a solute in a given volume of soltuion

Question 20

What is the unit for concentration

Answer 20

g / dm3

Question 21

Concentration = ?/?

Answer 21

Mass (g) / volume (dm3)