Alternative to Practical

Question 1

How do you test a compound for Carbonate (CO3)?

Answer 1

Add dilute hydrochloric acid
The solution effervescence (fizzes) and produces CO2

eg. CaCO3 + HCL —> CaCl2 + CO2 + H2O

Question 2

How will Hydrogen or Oxygen react when a splint is placed near it?

Answer 2

A lighted splint will burn with a pop sound if placed in Hydrogen

A glowing splint will ignite again in the presence of Oxygen

Question 3

How will litmus paper react in Ammonia (NH3) or Chlorine (Cl2)?

Answer 3

Red litmus paper will turn blue in Ammonia because of its basic property

Chlorine will bleach litmus paper white

Question 4

How is a gas tested for Carbon Dioxide (CO2)?

Answer 4

Bubbling the gas through lime water (Ca(OH)2) will result in a white precipitate of Calcium Carbonate

Question 5

Many negative ions can be tested with dilute nitric acid and aqueous Silver nitrate. What are these elements and how do they react from the test?

Answer 5

• Iodine
  A yellow precipitate of Silver Iodide is formed
• Chloride
  A white precipitate of Silver Chloride is formed
• Bromide
  A cream precipitate of Silver Bromide is formed

Question 6

How do you test a compound for Sulphate (SO4)?

Answer 6

Add dilute Hydrochloric acid, then add Barium Chloride solution.

The result will be a white precipitate of Barium Sulphate

Question 7

How do you test a compound for Nitrate (NO3)

Answer 7

Add Sodium Hydroxide (NaOH) and heat.

Ammonia gas is given off which can be tested with damp litmus paper

Question 8

What is a salt?

Answer 8

A salt is a compound formed when the hydrogen in an acid is replaced by a metal.

Question 9

How do you make a salt?

Answer 9

Mix a metal or an ionic compound with an acid of choice.

Hydrochloric acid will form a chloride salt, nitric acid will form a nitrate salt and so on and so forth.

eg. 2MgO + HCL —> MgCl2 + H2O

Question 10

What two solutions can identify positive ions?

Answer 10

Sodium Hydroxide (NaOH) and ammonia solutions (NH3)

Question 11

What positive ions react with NaOH to form a white precipitate hydroxide?

Answer 11

Calcium
Magnesium
Zinc
Aluminium

Question 12

Which positive ions react with NaOH to form gelatinous hydroxide precipitates?

Answer 12

Copper (II)
Forms a light blue precipitate
Iron (II) 
Forms a green precipitate
Iron (III) 
Forms a rust-brown precipitate

Question 13

How does ammonium (NH4) react with NaOH?

Answer 13

Ammonia gas is produced on warming

This can be tested with an indicator

Question 14

Which positive ion reacts with ammonia to form nothing?

Answer 14

Calcium

Question 15

What is a chemical equation for Titration?

Answer 15

Dilute acid + Alkali —> metal salt + water

An indicator should be used to indicate the neutralisation
Phenolphthalein turns colourless in acids and pink in basics

Question 16

What is the excess solid seen during titration or neutralisation?

Answer 16

The salt formed

It is then evaporated to concentrate the solution or crystallised

Question 17

What factors have direct proportion with reaction rate?

Answer 17

Concentration
Temperature
Pressure
Surface area

Question 18

In Yalta Cats Will Bounce on Cream.

What solutions are used for this?

Answer 18

Dilute nitric acid and aqueous Silver Nitrate

Question 19

When adding Sodium Hydroxide, which positive ion becomes a SOLUBLE hydroxide?

Answer 19

Aluminium hydroxide is soluble on excess giving a colourless solution

Question 20

When adding ammonia solution, which positive ion becomes dissolvable?

Answer 20

Copper (II) dissolves giving a deep blue solution

Question 21

Which positive ion becomes soluble in excess ammonia solution?

Answer 21

Zinc

Question 22

How does silver bromide react with ammonia solution?

Answer 22

It is only slightly soluble

Question 23

How does silver chloride react in ammonia solution?

Answer 23

It is soluble

Question 24

Which are the negative and positive electrodes?

Answer 24

The cathode is the negative electrode attracting positive ions

The anode is the positive electrode attracting negative ions

Question 25

In electrolysis, where does oxidation occur?

Answer 25

At the anode