C4 and C7

Question 1

What is avogadro’s constant

Answer 1

6.02x10^23

Question 2

Calculation for number of moles

Answer 2

Mass (g)/relative atomic mass or relative formula mass

Question 3

What is a mole

Answer 3

The relative formula mass in grams of a substance

Question 4

What do balanced symbol equations tell you

Answer 4

The number of moles of substances involved in a chemical reaction

Question 5

Equation work out the concentration in g/dm3

Answer 5

Amount of solute(g) / volume of solution (dm3)

x1000 if trying to find out cm3

Question 6

What does it mean if a solution is more concentrated

Answer 6

It has more solute in the same volume of solution than a less concentrated solution

Question 7

What is an exothermic reaction

Answer 7

When heat energy is given out (temp goes up)

Question 8

What is an endothermic reaction

Answer 8

Heat energy is transferred in (temp goes down)

Question 9

Examples of exothermic reactions

Answer 9

Combustion, neutralisation and oxidation

Question 10

Examples of endothermic reactions

Answer 10

Photosynthesis and thermal decomposition

Question 11

What solution is used in reusable warmers

Answer 11

Crystalisation of a supersaturated solution

Question 12

What kind of reaction is bond making

Answer 12

Exothermic
RR-foRming bonds Releases energy

Question 13

What kind of reaction is bond breaking

Answer 13

Endothermic
BB- Breaking bonds aBsorbs energy

Question 14

After calculating how can you tell if the reaction is exothermic or endothermic

Answer 14

If the number is negative it means it is an exothermic reaction and if positive it means it us an endothermic reaction

Question 15

What is activation energy

Answer 15

The minimum amount of energy required for a chemcial reaction to occur

Question 16

What is bond energy

Answer 16

The energy required to break the bonds between the two atoms