Chem Paper 1

Question 1

Which ion makes the solution acidic

Answer 1

H+ (hydrogen)

Question 2

Which indicator can be used to test if a solution is acidic

Answer 2

Universal indicator- if it turns from green to red/orange/yellow it is acidic

Question 3

Method to investigate amount of CO2 produced when different amount of calcium carbonate are reacted with hydrochloric acid

Answer 3

Measure 1g of calcium carbonate using a balance, place calcium carbonate in a conical flask, measure 50cm² of hydrochloric acid using a measuring cylinder, add hydrochloric acid to conical flask, immediately place the stopper and delivery tube in conical flask, record the total volume of gas produced. Repeat method with different amounts of calcium carbonate.

Question 4

This question is about salts.
Green copper carbonate and sulfuric acid can be used to produce
blue copper sulfate crystals.Excess copper carbonate is added to sulfuric acid.
Give three observations you would make.

Answer 4

green solid / powder, colourless solution, blue solution formed, copper carbonate disappears, fizzing / effervescence
, bubbles (of gas), stops fizzing, solid / powder left at the end, copper carbonate left at the
end.

Question 5

Plan an investigation to find the order of reactivity of three metals.
You should use the temperature change when each metal reacts with
hydrochloric acid

Answer 5

measure 50cm³ of (hydrochloric) acid in a polystyrene cup, measure the initial temperature of hydrochloric acid, with a thermometer, add 1g of one metal, stir and record the highest temperature reached. repeat for each metal with same mass in the same physical state (powder, lump, etc),with the same volume and / or concentration of (hydrochloric) acid, use results to arrange metals in order of reactivity, most reactive metal has the largest temperature change

Question 6

What are the Group 7 elements known as?

Answer 6

Halogens

Question 7

Why do Group 7 elements react in similar ways?

Answer 7

They all have 7 electrons in their outer shell

Question 8

Suggest properties that make fullerenes useful in nanotechnology

Answer 8

conducts heat, conducts electricity, very high length to diameter
ratio

Question 9

An alloy of aluminium contains small amounts of other metals. Explain why other metals are added to aluminium.

Answer 9

other metal atoms have different sizes to aluminium atoms, so the layers of aluminium atoms are distorted so the layers cannot slide which makes the alloy harder.

Question 10

Compare the bonding within the chains with the forces between the chains in this polymer.

Answer 10

covalent bonds between atoms in the chain,
intermolecular forces between the chains
covalent bonds are strong and
intermolecular forces are weak

Question 11

What is meant by the term strong acid?

Answer 11

completely ionises in aqueous solution

Question 12

Describe how magnesium can be used to distinguish between a strong acid and a weak acid of the same concentration.

Answer 12

fizzing / effervescence or
magnesium disappears at a greater rate with a strong
acid

Question 13

The concentration of hydrochloric acid is increased by a factor of 100
What is the change in pH?

Answer 13

(pH) decreases by (a unit of) 2

Question 14

Describe how sodium metal conducts electricity.

Answer 14

delocalised electrons
carry (electrical) charge through
the metal / sodium

Question 15

Explain how sodium chloride can conduct electricity.

Answer 15

conducts electricity when liquid / molten because ions ions are free to move