acids, alkalis and titrations

Question 1

What pH is strongest acid and alkali?

Answer 1

• acid=0

- alkali=14

Question 2

What are indicators used for?

Answer 2

-estimating the pH of a solution

Question 3

What is universal indicator and what is it used for?

Answer 3

• combination of dyes which give all the colours

- used to find the pH of an aqueous solution

Question 4

what is litmus paper used for?

Answer 4

• tests whether a solution is acidic or alkaline because it changes colour around pH 7
• red in acidic solutions, purple in neutral and blue in alkaline

Question 5

what is phenolphthalein used for?

Answer 5

-changes from colourless in acidic solutions to bright pink in alkaline solutions

Question 6

what is methly orange used for?

Answer 6

-changes from red in acidic solutions to yellow in alkaline solutions

Question 7

What can acids be neutralised with?

Answer 7

-bases

Question 8

What is a base?

Answer 8

-a substance that can neutralise an acid. They are proton acceptors and acids are proton donors

Question 9

What is an acid?

Answer 9

-a source of hydrogen ions (H+)

Question 10

What is an alkali?

Answer 10

-a source of hydroxide ions (OH-)

Question 11

What happens when an acid neutralises a base?

Answer 11

-the products are neutral

Question 12

What is produced when acid reacts with bases?

Answer 12

-salt + water

Question 13

What salt does hydrochloric acid produce?

Answer 13

-chloride salts

Question 14

What salt does sulfuric acid produce?

Answer 14

-sulfate salts

Question 15

What salt does nitric acid produce?

Answer 15

-nitrate salts

Question 16

Which reactions form salt + water?

Answer 16

• acid + metal oxide

- acid + metal hydroxide

Question 17

What reaction forms ammonium salt?

Answer 17

-acid + ammonia

Question 18

What reaction forms salt+water+carbon dioxide?

Answer 18

-acid + metal carbonate

Question 19

Soluble or insoluble?

-common salts of sodium, potassium and ammonium

Answer 19

-soluble

Question 20

Soluble or insoluble?

-nitrates

Answer 20

soluble

Question 21

Soluble or insoluble?

common chlorides

Answer 21

-soluble except silver chloride and lead chloride

Question 22

Soluble or insoluble?

common sulfates

Answer 22

-soluble except lead, barium, calcium sulfate

Question 23

Soluble or insoluble?

common carbonates

Answer 23

-insoluble except sodium, potassium, ammonium

Question 24

Soluble or insoluble?

common hydroxides

Answer 24

-insoluble except sodium, potassium, calcium

Question 25

How can u make a soluble salt?

Answer 25

-by reacting an acid that contains one of the ions you want in the salt with an insoluble base that contains the other ion you need

Question 26

Steps for making a soluble salt (5)

Answer 26

• heat the acid in a water bath which speeds the reaction between acid and insoluble base. Do this in fume cupboard
• add the base to acid-will react to produce a soluble salt + water
• filter off the excess solid to get a solution containing salt and water
• heat the solution gently using bunsen to slowly evaporate some water. Leave solution to cool and allow salt to crystallise