mistakes

Question 1

if sam wants to prepare a pure sample of lithium sulphate using an acid and an alkali, name ones that would be suibtable

Answer 1

sulphuric acid, lithium oxide

Question 2

if you want to get a precise titre, what should you do?

Answer 2

repeat until you get concordant results

Question 3

what is an isotope

Answer 3

Isotopes are different ATOMS of the same element that contain the same number of protons but a different number of neutrons.

Question 4

what is the test for water?

Answer 4

Add anhydrous copper(II) sulfate to a sample. If water is present, the anhydrous copper(II) sulfate will change from white to blue. This is because the copper(II) sulfate becomes hydrated copper(II) sulfate, which is a bright blue crystal.

Question 5

how can you determine that the water is pure?

Answer 5

determine the boiling point (should be 100 degrees), determine the freezing point (0) or determine the density (1g/cm^3)

Question 6

why do people use cracking?

Answer 6

• there is a grater supply of longer chain hydrocarbons
• higher demand for shorter chain alkanes like petrol
• alkenes are used to make pilymers

Question 7

(d) Ethanol can be manufactured by the hydration of ethene. The equation for this
reaction is

C2H4(g) + H2O(g) → C2H5OH(g)

(i) Identify the catalyst and state the temperature used in this process.

Answer 7

phosphoric acid / H3PO4
any value in range 250 – 350 °
C

Question 8

why is the products of cracking not pure?

Answer 8

there are 2 or more products, therefore, they are a mixture

Question 9

What type of reaction occurs when sucrose turns into glucose? what is this reaction called? what is the catalyst used called?

Answer 9

fermentation, zymase, hydration

Question 10

In industry, the conversion of propene to an alcohol uses the same conditions
as those used in the conversion of ethene to ethanol.
Identify a suitable catalyst and temperature for these conversions.

Answer 10

phosphoric acid / phosphoric(V) acid / H3PO4
300 (°C)