chemistry paper 1

Question 1

why do elements in the same group act similar?

Answer 1

they have the same number of outer electrons

Question 2

what is the attraction between atoms that have the opposite charge?

Answer 2

electrostatic attraction

Question 3

what is a positively charged ion and a negatively charged ion called?

Answer 3

positive - cation

negative - anion

Question 4

define element

Answer 4

a substance made up of atoms that all have the same number of protons in the nucleus

Question 5

define compound

Answer 5

substances formed from two or more elements, the atoms of each are in fixed proportions throughout the compound and they’re held together by chemical bonds

Question 6

define mixture

Answer 6

substances formed from two or more elements where there are no chemical bonds between the atoms

Question 7

how does concentration impact equilibrium?

Answer 7

forward reaction slows down as the reactants react, backwards reaction speeds up

Question 8

what happens at equilibrium?

Answer 8

both reactions are still happening, no overall effect

Question 9

when can equilibrium occur?

Answer 9

in a closed system, nothing can get in or out

Question 10

how is the reactivity series ordered?

Answer 10

how easily they lose electrons to form positive ions

Question 11

acid + metal = ???

Answer 11

salt + hydrogen

Question 12

metal + water = ???

Answer 12

metal hydroxide + hydrogen

Question 13

how reactive do metals need to be to react with water?

Answer 13

very - high up reactivity series

Question 14

define oxidation

Answer 14

gain of oxygen, loss of electrons

Question 15

define reduction

Answer 15

gain of electrons, loss of oxygen

Question 16

which metals can be extracted by reduction with carbon?

Answer 16

metals lower than carbon on the reactivity series

Question 17

how do you extract metals higher than carbon on the reactivity series?

Answer 17

electrolysis

Question 18

what are the components needed in electrolysis?

Answer 18

electrolyte - a molten or dissolved ionic compound

electrode - metals where the ions move toward

Question 19

where do the positive and negative ions go during electrolysis?

Answer 19

positive - cathode to be reduced

negative - anode to be oxidised

Question 20

half equations of aluminium oxide

Answer 20

Al3+ + 3e- –> Al

2O2- –> O2 + 4e-

Question 21

what does the atom economy tell you?

Answer 21

the % of reactants forming useful products

Question 22

what did bohr propose?

Answer 22

electrons orbit the nucleus in fixed positions

Question 23

what did jj thomson suggest?

Answer 23

the plum pudding model. stoke are a ball of positive charge with electrons stuck in

Question 24

what did rutherford prove?

Answer 24

he proved the plum pudding model was wrong by firing alpha particles at a sheet of gold, they passed through showing the atom has a nucleus

Question 25

how is % mass calculated?

Answer 25

RAM x No of atoms / RFM

x 100

Question 26

how do you calculate moles

Answer 26

mass / RFM

Question 27

what is a limiting reactant

Answer 27

the reactant used up in a reaction

Question 28

what is percentage yield

Answer 28

a comparison between actual and theoretical yield

Question 29

how is percentage yield calculated

Answer 29

mass of products made / theoretical mass

x 100

Question 30

what does one mole of any gas occupy

Answer 30

24dm3 at 20 oC

Question 31

how do you work out volume of a gas

Answer 31

mass / RFM x 24

Question 32

how are metals lower then carbon on the reactivity series extracted

Answer 32

using carbon