ACIDS,BASES AND SALTS

Question 1

acids have

Answer 1

sour taste

Question 2

bases have

Answer 2

bitter taste

Question 3

acids change

Answer 3

blue litmus to red

Question 4

bases change

Answer 4

red litmus to blue

Question 5

natural indicators

Answer 5

litmus, turmeric

Question 6

synthetic indicators

Answer 6

methyl orange, phenolphthalein

Question 7

litmus is

Answer 7

the purple dye extracted from lichen

Question 8

lichen belongs to

Answer 8

the division thallophyta

Question 9

natural materials that indicate the presence of acids or bases

Answer 9

red cabbage leaves, turmeric, coloured petals of flowers such as hydrangea, petunia and geranium

Question 10

substances whose odour changes in acidic or basic media

Answer 10

olfactory indicators

Question 11

acid + metal

Answer 11

salt + hydrogen gas

Question 12

Na2ZnO2

Answer 12

sodium zincate

Question 13

different forms of calcium carbonate

Answer 13

limestone, chalk, and marble

Question 14

all metal carbonates and hydrogen carbonates react with acids to give

Answer 14

a corresponding salt, carbon dioxide, and water

Question 15

metal carbonate/ hydrogen carbonate + acid

Answer 15

salt + CO2 + H2O

Question 16

The reaction between an acid and base is

Answer 16

known as neutralization reaction

Question 17

base + acid

Answer 17

salt + water

Question 18

metal oxide + acid

Answer 18

salt + water

Question 19

the blue-green color of copper sulfate solution is due to

Answer 19

formation of copper chloride

Question 20

metallic oxides are

Answer 20

basic in nature

Question 21

non-metallic oxides are

Answer 21

acidic in nature

Question 22

the bulb will glow

Answer 22

in the case of acids

Question 23

electric current is carried

Answer 23

through the acidic solution by ions

Question 24

cations present in acids

Answer 24

H+

Question 25

hydrogen ions in an acid

Answer 25

are produced in water

Question 26

bases generate

Answer 26

OH- ions in water

Question 27

bases soluble in water are

Answer 27

known as alkalis

Question 28

alkalis are

Answer 28

soapy to touch,

bitter and corrosive

Question 29

the acid must be always

Answer 29

added slowly to the water while constantly stirring it

Question 30

water can’t be added to a concentrated acid

Answer 30

because it is a highly exothermic reaction that may cause the mixture to splash and cause burns on the skin. clothes etc

Question 31

the glass container may also break

Answer 31

due to excessive local heating

Question 32

mixing an acid or base with water results in a decrease in the concentration of ions, per unit volume

Answer 32

this process is called dilution and the acid or base is said to be diluted

Question 33

the universal indicator

Answer 33

shows different colours at different concentrations of hydrogen ions in a solution

Question 34

pH scale

Answer 34

a scale for measuring hydrogen ion concentration in a solution

Question 35

the p in ph stands for

Answer 35

potenz in german meaning power

Question 36

Higher the hydronium concentration

Answer 36

lower is the pH value

Question 37

the pH of a neutral solution

Answer 37

7

Question 38

the pH of an acidic solution

Answer 38

less than 7

Question 39

pH value increasing from 7 to 14

Answer 39

alkali solution, increase in OH- ion concentration

Question 40

the pH of gastric juice

Answer 40

1.2

Question 41

the pH of lemon juice

Answer 41

2.2

Question 42

the pH of pure water and blood

Answer 42

7.4

Question 43

the pH of milk of magnesia

Answer 43

10

Question 44

the pH of sodium hydroxide solution

Answer 44

about 14

Question 45

strong acids

Answer 45

give out more H+ ions

Question 46

weak acids

Answer 46

give out fewer H+ ions

Question 47

our body works within the pH range of

Answer 47

7.0 to 7.8

Question 48

acid rain

Answer 48

when the pH of rain water is less than 5.6