Metals, Alkalis And Salts

Question 1

The acidity or alkalinity of something is measured in…

Answer 1

pH

Question 2

… Can be used to measure the approximate pH of a solution

Answer 2

Universal indicator

Question 3

pH indicators are…

Answer 3

Chemicals that change colours at different pHs

Question 4

Common pH indicators are…

Answer 4

Universal Indicator
Litmus Paper (red in acid, blue in alkali
Methyl orange
Phenolphthalein

Question 5

Phenolphthalein is which colours?

Answer 5

Colourless in acidic or neutral
Pale pink in pH 9
Pink in alkali pH 10 - 14

Question 6

Methyl Orange is which colours?

Answer 6

Red in acid pH 0 - 3
Orange at pH 4
Yellow in neutral and alkali pH 5 - 14

Question 7

Litmus paper is which colours?

Answer 7

Red in acid pH 0 - 5
Purple at pH 7
Blue in alkali pH 8 - 14

Question 8

Alkalis are sources of…

Answer 8

OH- ions

Question 9

Acids are sources of…

Answer 9

H+ ions

Question 10

Metal and Acid reactions are both … And …

Answer 10

Redox and neutralisation

Question 11

Hydrochloric acid reacts with metals and metal compounds to form

Answer 11

A metal chloride

Question 12

Sulphuric acid reacts with metals and metal compounds to form a…

Answer 12

Metal sulphate

Question 13

Metal + Acid =

Answer 13

Salt + hydrogen

Question 14

MASH is a … Reaction

Answer 14

Redox

Question 15

What are the half equations for this?:

Mg + 2HCl = MgCl2 + H2

Answer 15

Mg = Mg(2+) + 2e-

2H(+) + 2e- = H2

Question 16

Metal Oxide + Acid =

Answer 16

Salt and water

Question 17

Metal oxide + acid is a … Reaction

Answer 17

Neutralisation

Question 18

Metal Carbonate + Acid =

Answer 18

Salt + Water + Carbon Dioxide

Question 19

Metal carbonate + acid is a … Reaction

Answer 19

Neutralisation

Question 20

How to prepare soluble salts using titration (finding the exact amounts needed for neutralisation)

Answer 20

• A burette is filled with HCl
• A known quantity of alkali is in a conical flask
• The alkali contains an indicator
• the tap on the burette is opened to drop the acid in drop by drop
• when enough acid has been added to neutralise the alkali, the indicator will change colour and you turn off the tap
• the titration can be repeated using the same amounts without an indicator to contaminate any possible crystals

Question 21

The process of making a solid come from a solution is called..,

Answer 21

Precipitation (the solid is called a precipitate)

Question 22

An insoluble salt can be made by…

Answer 22

Reacting the appropriate soluble salt with an acid or an alkali or another salt

Question 23

Prepare silver chloride

Answer 23

Use a soluble silver salt
Use a soluble chloride
(All nitrates and all sodium salts are soluble so they are safe bets I.e. Silver nitrate and sodium chloride)

Question 24

What is the bromsted-Lowry theory?

Answer 24

An acid donates a proton

A base accepts a proton

Question 25

Hydrochloric acid is a solution of...

Answer 25

Hydrogen chloride in water

Question 26

When hydrogen loses its only electron it becomes a...

Answer 26

Hydrogen ion, which is just a proton

Question 27

When hydrogen chloride dissolves in water...

Answer 27

A proton (the hydrogen ion) is transferred to the water.

Question 28

The equation for hydrogen chloride dissolving in water is...

Answer 28

H2O(l) + HCl(g) = H3O+(aq) + Cl-(aq)

Question 29

A H3O+ ion is called a...

Answer 29

Hydroxonium ion. We normally write it as H+(aq), and you can think of it as a hydrogen ion riding on a water molecule

Question 30

Water is a ... Molecule

Answer 30

Polar

Question 31

Polar molecules are...

Answer 31

Slightly negative at one end (e.g. The oxygen in water) and slightly positive at the other (e.g. The hydrogen in water)

Question 32

When something such as sodium chloride is being dissolved in water...

Answer 32

The slightly positive ends of the water molecule cluster around the negative chloride ions, while the positive ends cluster around the sodium. The water molecules then literally pull apart the sodium chloride crystal

Question 33

To break bonds (between the salt + and - ions and between the water molecules) you need ..., therefore ... Reactions are unlikely

Answer 33

Energy, therefore endothermic processes are unlikely. If a substance is soluble it is because more energy is formed when water molecules make strong bonds to the salt ions, paying back the energy required to break bonds

Question 34

Polar molecules 'pulling' works on...

Answer 34

Not every substance. E.g. MgO is only slightly soluble due to the strong bonds

Question 35

Methylbenzene is ... A polar molecule

Answer 35

Not

Question 36

HCl won't be formed in methylbenzene as...

Answer 36

It is not polar and so unable to break apart the hydrogen and chlorine