How Much? & Rates and Energy

Question 0

Protons and neutrons have the same…

Answer 0

Mass

Question 1

Mass of atoms, relative masses of proton and neutrons

Answer 1

1

Question 2

Mass number

Answer 2

Total number of protons and neutrons in an atom

Question 3

Why do we count only protons and neutrons to calculate the mass number of an atom?

Answer 3

As the mass of an electron is very small so the mass of an atom is made of it’s protons and neutrons

Question 4

Atoms of the same element all have the same

Answer 4

Atomic number

Question 5

Would should always be the same amount in an atom

Answer 5

Protons and electrons

Question 6

Isotopes

Answer 6

Atoms of the same element with different numbers of neutrons

Question 7

Mass number?

Answer 7

Top number on symbol

Question 8

Atomic number

Answer 8

Bottom number

Question 9

Neutrons how can you find the amount

Answer 9

Mass number - atomic number = neutrons in atom

Question 10

How many protons, electrons, neutrons in an atom of 19 (top) F 9 (bottom)

Answer 10

Protons and electrons = 9 neutrons = 10

Question 11

Relative atomic masses ( A r)

Answer 11

What we use to weigh atoms as too small

Question 12

Relative atomic mass of an element is an ..

Answer 12

Average value

Question 13

Real stove formula mass (M r) is found by

Answer 13

Adding up relative atomic masses of the atoms in it’s formula

Question 14

Calculate the M r of calcium chloride CaCl2

Answer 14

A r of Ca = 40 A r of CI = 35.5

So M r = 40 + (35.5 multiplied by 2) = 111

Question 15

What is the mass of one mole of sodium hydroxide NaOH

Answer 15

A r of Na = 23 A r of O = 16 A r of H = 1 so 1 mole NaOH = (23+16+1)g = 40g

Question 16

Percentages how do you work them out

Answer 16

Relative atomic masses multiplied by relative formula mass answer multiplied by 100 = percentage

Question 17

What is the percentage of carbon in carbon dioxide? CO2 carbon =12 O = 16

Answer 17

C= 12 O=16
M r of CO2 = 12 + (2 multiplied by 16) = 44
Percentage of carbon = (12/44) multiplied by 100= 27.3%

Question 18

Empirical formula

Answer 18

Simplest ratio of atoms or ions in a compound

Question 19

Yield of a chemical process

Answer 19

How much you actually make

Question 20

Percentage yield

Answer 20

Compares amount made with maximum amount that could be made

Question 21

Calculating percentage yield

Answer 21

Percentage yield = (amount of product collected divided by maximum amount of product possible) multiplied by 100

Question 22

Maximum amount of product possible calculated by

Answer 22

Balanced equation for the reaction

Question 23

Why is it not usually possible to get 100% yield from a chemical reaction?

Answer 23

Because some product may be lost collected from apparatus

Question 24

Why should chemical manufacture use reactions with high yields

Answer 24

Reduce waste reduce pollution and makes production more sustainable

Question 25

Reversible reaction

Answer 25

Products of the reaction can react to make the original reactants

Question 26

Example of reversible reaction

Answer 26

Ammonium chloride ammonia + hydrogen chloride

Question 27

Chemical analysis is used to ..

Answer 27

Identify food additives

Question 28

What method can be used to analyse the colours in food

Answer 28

Chromatography

Question 29

What is the main purpose of the gas chromatography column in GC-MS analysis?

Answer 29

To separate a mixture

Question 30

How is relative molecular mass shown in a mass spectrum

Answer 30

Furthest to the right

Question 31

Rates and energy, rate of a reaction measures

Answer 31

How fast it is

Question 32

Methods used to measure rate of reaction

Answer 32

Rate of reaction= amount of reactant used divided by time

Question 33

Rate of reaction on a graph can be found

Answer 33

By the gradient

Question 34

Particles must do what to react

Answer 34

Particles Must collide with a certain amount of energy before they can react

Question 35

Activation energy

Answer 35

Minimum energy needed to react

Question 36

Factors that increase the chance of collisions

Answer 36

Temp, concentration of solutions, pressure of gases, surface area of solids, use of catalysts will all increase the rate of reaction

Question 37

Why can catalysts be used over and over again

Answer 37

As not used up

Question 38

Why do different reactions need different catalysts

Answer 38

Catalysts often work with only one type of reaction

Question 39

Exothermic reactions

Answer 39

Reactions that transfer energy to the surroundings

Question 40

Exothermic reaction examples

Answer 40

Combustion buring of fuels, oxidation respiration

Question 41

Endothermic reactions

Answer 41

ReCtions that take in energy from surroundings

Question 42

What are the two ways that show that a reaction is endothermic

Answer 42

Decrease in temp and some need supply of energy

Question 43

Ectothermic changes can be used in

Answer 43

Hand earners based on recrystallisation

Question 44

Endothermic changes can be used in

Answer 44

Instant cold packs