Acids Bases And Salts

Question 1

What colour does litmus go in an acidic solution?

Answer 1

Red

Question 2

What colour does litmus go in a neutral solution?

Answer 2

Purple

Question 3

What colour does litmus go in an alkaline solution?

Answer 3

Blue

Question 4

What colour does phenolphthalein go in an acidic solution?

Answer 4

Colourless

Question 5

What colour does phenolphthalein go in an alkaline solution?

Answer 5

Pink

Question 6

What colour does methyl orange go in an acidic solution?

Answer 6

Red

Question 7

What colour does methyl orange go in a neutral solution?

Answer 7

Yellow

Question 8

What colour does methyl orange go in an alkaline solution?

Answer 8

Yellow

Question 9

How do you determine the strength of an acid or alkali?

Answer 9

Red- strongly acidic
Green- neutral
Purple- strongly alkaline

Question 10

What are all acids dissolved in water?

Answer 10

Aqueous solutions

Question 11

What is the use of universal indicator?

Answer 11

To measure the approximate pH value and how acidic or alkaline something is

Question 12

What are the acids in aqueous solutions sources of?

Answer 12

Hydrogen ions

Question 13

What are alkalis in an aqueous solution source of?

Answer 13

Hydroxide ions

Question 14

Acid+metal

Answer 14

Salt+hydrogen

Question 15

Acid+metal carbonate

Answer 15

Salt+carbon dioxide+water

Question 16

Acid+metal oxide

Answer 16

Salt+water

Question 17

Acid+metal hydroxide

Answer 17

Salt+water

Question 18

What can neutralise an acid?

Answer 18

An alkaline

Question 19

Describe how to carry out an acid alkaline titration

Answer 19

1. Add 25cm2 of a soluble base (snap) to a conical flask using a 25ml pip eye and add 5 drops suitable indicator (phenolphthalein)
2. Fill the bursts, using a funnel, with an acid and run through the tip into a small beaker until it is on the scale
3. Note the volume
4. Add the acid to the soluble base solution in small volumes swirling after each addition,continue until the solution just changes colour permanently
5. Record the volume
6. Repeat for a more reliable result

Question 20

Which all compounds are soluble?

Answer 20

SNAP
Sodium
Nitrate
Potassium
Ammonium

Question 21

Example of an insoluble salts?

Answer 21

Barium surface
Barium carbonate
(Carbonates except snap)

Question 22

Sulphuric acid

Answer 22

H2SO4 (sulfate)

Question 23

Nitric acid?

Answer 23

HNO3 (nitric acid)

Question 24

Hydrochloric acid?

Answer 24

HCl (chloride)

Question 25

What is a proton donor?

Answer 25

Acids

Question 26

What is a proton acceptor?

Answer 26

Base

Question 27

Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from a insoluble reactant

Answer 27

1. Start with adding an excess(there is more than enough to react with all the acid) of an insoluble base to a beaker containing a soluble acid, which will produce a soluble salt and water. 2. After the reaction is complete, filter off the excess of the insoluble base 3. Transfer the solution to an evaporating basin and heat the solution to boil off some water and concentrate the solution 4. Dry the crystals by leaving them in a warm place

Question 28

Describe an experiment to prepare a pure, dry sample of a soluble salt, starting from an acid and alkali

Answer 28

1. Add a measured volume of the acid 2. Slowly add the alkali drop by drop while stirring, neutralisation reaction will happen and form salt and water 3. To know that the reaction is complete add a few drops of a pH indicator (phenolphthalein) the solution will turn pink when the alkali neutralises the acid 4. Gently heat the solution, to evaporate water,salt crystals will then begin to form 5. Allow the solution to cool, then filter off any remaining and leave the salt in a warm place to get a pure dry sample of the salt

Question 29

Describe an experiment to prepare a a dry, pure sample of an insoluble salt starting from two soluble reactants

Answer 29

1. Measure the same amount of two soluble reactants and mix them in a beaker 2. A white precipitate will form 3. Filter the mixture through filter paper, and the insoluble salt will be left on the filter paper, while the soluble salt and any excess passes through the filter paper into a beaker 4. Wash out the residue of the unsubtle salt with distilled water, this is to make sure the salt is not contaminated 5. Transfer the filter paper with the unsubtle salt into a warm place and let it dry, to get a dry, pure sample of an insoluble salt using two soluble reactants

Question 30

Precipitation reaction

Answer 30

One soluble salt+ soluble salt= insoluble salt

Question 31

Excess solid

Answer 31

Acid+ insoluble base (not snap)

Question 32

Titration

Answer 32

Acid+ snap

Question 33

Copper sulfate is

Answer 33

Soluble

Question 34

Lead sulfate is

Answer 34

Insoluble

Question 35

Equation for moles calculations involving solutions

Answer 35

Moles= concentration x volume Mol= mol/dm3 x dm3

Question 36

Cm3 to dm3

Answer 36

Cm3/1000= dm3

Question 37

How to convert g/dm3 to mol/dm3

Answer 37

Divide by Mr mol/dm3 x Mr = g/dm3

Question 38

What does phenolphthalein go in a neutral solution?

Answer 38

Colourless