Acids Bases And Salts

Question 1

What is the colour of litmus in a acidic solution

Answer 1

Red

Question 2

What is the colour of litmus in a neutral solution

Answer 2

Purple

Question 3

What is the colour of litmus in a alkaline solution

Answer 3

Blue

Question 4

What is the colour of phenolphthalein in a acidic solution

Answer 4

Colourless

Question 5

What is the colour of phenolphthalein in a neutral solution

Answer 5

Colourless

Question 6

What is the colour of phenolphthalein in a alkaline solution

Answer 6

Pink

Question 7

What is the colour of methyl orange in a acidic solution

Answer 7

Red

Question 8

What is the colour of methyl orange in a neutral solution

Answer 8

Yellow

Question 9

What is the colour of methyl orange in a alkaline solution

Answer 9

Yellow

Question 10

What is the use of universal indicator

Answer 10

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

Question 11

What are acids in a aqueous solution a source of

Answer 11

Hydrogen

Question 12

Mash

Answer 12

Metal+acid—> salt+hydrogen

Question 13

What are ions and alkalis in a aqueous solution a source of

Answer 13

Hydroxide ions

Question 14

Baws

Answer 14

Base+acid—>salt+water

Question 15

Acid+metal—>

Answer 15

Salt+hydrogen

Question 16

Acid+metal carbonate—>

Answer 16

Salt+carbon dioxide + water

Question 17

Acid+metal oxide—>

Answer 17

Salt+water

Question 18

Acid +metal hydroxide—>

Answer 18

Salt+water

Question 19

What neutralises acids

Answer 19

Alkalis

Question 20

Describe how to carry out titration

Answer 20

Add 25cm3 of a soluble base (potassium hydroxide) solution to a conical flask using a 25ml pipette add 4-5 drops of an indicator (phenolphthalein). Fill the burette using an acid (hydrochloric acid) and run through the tip into small beaker until it is on the scale. Note down the volume on the burette. Add the acid to the base solution in small volumes swirling after each addition. Continue until the solution changes colour permanently. Note the burette volume and calculate the volume of acid added. Repeat

Question 21

What are the snap salts

Answer 21

Sodium, potassium, ammonium, nitrate

Question 22

Which chlorides are insoluble

Answer 22

Lead(II) chloride and silver chloride

Question 23

What sulfates are insoluble

Answer 23

Lead (II) sulfate, barium sulfate and calcium sulfate

Question 24

What carbonates are soluble

Answer 24

Sodium, potassium, ammonium carbonates

Question 25

Most Common chlorides are…

Answer 25

Soluble

Question 26

Most common sulfates are…

Answer 26

Soluble

Question 27

Most common carbonates are…

Answer 27

Insoluble

Question 28

What metal hydroxides are soluble

Answer 28

Sodium, potassium and ammonium hydroxides-SAP

Question 29

Most metal hydroxides are…

Answer 29

Insoluble

Question 30

What is a proton donor

Answer 30

An acid

Question 31

What is a proton acceptor

Answer 31

A base (alkali)

Question 32

What are alkalis soluble in

Answer 32

Water

Question 33

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

Answer 33

Choose an insoluble salt such as lead (II) chloride. Dissolve a soluble salt such as sodium sulfate in water to form a solution. Add sodium sulfate solution to the lead(II) chloride solution in a beaker. This will cause a displacement reaction forming lead sulfate which is insoluble. Use a filter paper and funnel to seperate the precipitation from the remaining solution. The solution which passes through the filter will contain the soluble salt. Rinse the precipitate with distilled water to remove any impurities. Place the washed precipitate in a warm place to dry. Once dry wash crystals with distilled water. This obtains a pure dry sample of a soluble salt.

Question 34

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

Answer 34

Start with some hydrochloric acid and an alkali, sodium hydroxide. Start by doing a neutralisation reaction by adding 10cm3 of hydrochloric acid to a beaker. Using a PH indicator such as phenolphthalien add in 5 drops. Then add in sodium hydroxide until it reaches a neutral pH which can be detected by a colour change. Once neutralisation is complete transfer the salt solution into an evaporating dish then place that over a Bunsen burner on a low heat. As the water begins to evaporate crystals will start to form. Continue heating until most of the water evaporates of if the mixture starts to boil. Allow the mixture to cool then wash in distilled water to get rid of impurities.

Question 35

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

Answer 35

Prepare two soluble salts such as sodium sulfate and barium chloride. Dissolve 25cm3 of sodium sulfate in a beaker with distilled water. In a separate beaker dissolve 25cm3 of barium chloride with distilled water. Slowly pour the barium chloride into the sodium sulfate solution. A white precipitate of barium sulfate will form immediately. One the precipitate has formed filter the solution separating the barium sulfate from the sodium chloride. Rinse the precipitate on the filter paper with distilled water purifying the salt. Leave the barium sulfate precipitate toe dry in a warm place to obtain a dry sample

Question 36

How do you prepare a sample of pure dry hydrated copper sulfate crystals

Answer 36

Measure 15cm3 of sulfuric acid into a boiling tube. Place the boiling tube into a boiling water bath for 2-3 minutes. Weigh about 2g of black copper oxide into a weighing boat. Add about half of the copper oxide into the sulfuric acid, shake slightly then return to the water bath. After the reaction has take place adding the remaining copper oxide then place into the water bath again. There should now be some cooler oxide settling at the bottom of the tube. Filter the solution the place the filtered mixture into an evaporating dish. Heat the solution over a Bunsen burner until just boiled. Leave the solutions to cool then wash with distilled water. Then allow the crystals to dry.

Question 37

How do you prepare a sample of pure dry lead sulfate.

Answer 37

Measure 10cm3 of lead nitrate in a beaker. Add 10cm3 of potassium sulfate to the beaker. Filter the precipitate and leave the residue on the filter paper. Then rinse with distilled water. Carefully remove the filter paper from the funnel and leave to dry

Question 38

What is the equation linking volume, moles and concentration

Answer 38

Moles (mol)=concentration (mol dm-3) x volume (dm3)