ch7-acids and alkalis

Question 1

whatre acids

Answer 1

substances that produce H+ ions 9hydrogen0 when dissolved in water

Question 2

what are bases

Answer 2

substances that neutralise acids

Question 3

what is an alkali

Answer 3

a soluble hydroxide

Question 4

what is a neautralisation reaction

Answer 4

when acids react with bases to form salt and water

Question 5

what do soluble hydroxides (alkalis) produced when dissolved in water

Answer 5

OH- (hydroxide) ions

Question 5

whats a ph scale

Answer 5

a measure of how acidic or alkaline a solution is

Question 5

whats the ph scale of acids

Answer 5

0-6 (red in universal indicator)

Question 6

whats the ph scale of alkalis

Answer 6

8-14 (purple in univeral indicators)

Question 7

what do hydrogen ions do

Answer 7

make substances acidic

Question 8

what do hydroxide ions do

Answer 8

make substances alkaline

Question 9

what do the salts produced in neutralisations between acids and bases or alkaline solutions depend on

Answer 9

• the acid used (hydrochloric acid produces chlorides, nitric acid produces nitrates, sulfuric acid produces sulfates)
• the metal in the base or alkali.

Question 10

what does hydrochloric acid produce in neutralisation reactions

Answer 10

chlorides

Question 11

what does nitric acid produce in neutralisation reactions

Answer 11

nitrates

Question 12

what does sulfuric acid produce in neutralisation reactions

Answer 12

sulfates

Question 13

what is the basic equation for neutralisation reactions

Answer 13

H+ ions (from acid) + OH- ions (from alkali) -> H20

Question 14

what do ammonia dissolved in water produce

Answer 14

alkaline solution, usually ammonium salts

Question 14

what happens to calcium hydroxide (limewater) in water

Answer 14

reacts with carbon dioxide to form calcium carbonate

Question 15

how can salts be made

Answer 15

by reaction a metal with an acid to produce salt and hydrogen

Question 16

what is a salt

Answer 16

a compound formed when hydrogen is replaced by either metal or ammonium ions

Question 17

acid+ metal ->,,,

Answer 17

salt + hydrogen

Question 18

how can salts be crystalised out of a solution

Answer 18

evaporating off the water from the formed solution to form a solid salt

Question 19

whatre the 3 ways u can make soluble salts

Answer 19

react acids with
-base (salt+water)
-metal (salt+hydrogen)
-alkali (salt+water)

Question 20

how can insoluble salts be made

Answer 20

by reaction 2 solube salts to produce a precipitate

Question 21

how can precipitation be used

Answer 21

to remove unwanted ions from solutions: for example, in treating water for drinking or in treating effluent.