2019 Paper 1

Question 1

describe what you would see when a group 1 element reacts with chlorine

Answer 1

white solid forms

Question 2

when reading the volume from a burette do you read it from the top or bottom

Answer 2

from the top

Question 3

suggest why its better to use nano particles rather than fine particles in a suncream

Answer 3

they have a larger surface area to volume ratio

Question 4

Give one limitation of using a dot and a cross diagram to represent molecules

Answer 4

its not 3 dimensional

Question 5

give the half equation for the production of oxygen during electrolysis at the anode

Answer 5

2O2- → O2 + 4e-

Question 6

why should excess hydrogen be collected and burned when it is produced in a reaction

Answer 6

because its explosive in air

Question 7

why is a polystyrene cup used in temperature change practical

Answer 7

polystyrene is a better thermal insulator so it transfers less thermal energy to the surroundings

Question 8

how to tell when something is exothermic and endothermic or exothermic

Answer 8

more heat energy is released when making the bonds than was taken in when breaking bonds so the reaction is exothermic