Acids Bases and salts

Question 1

Define acids and bases

Answer 1

Acids - Sour, diff types
Soluble
Blue to red
Less than 7

Bases - bitter
Red to blue
More than 7

Question 2

What is litmus

Answer 2

Extracted frm lichen used as indicator
Natural indicators - turmeric, methyl orange phenolphthalein

Question 3

What are acid base indicators

Answer 3

To check if substance is acid or base or neutral by change in colour

Question 4

What is olfactory

Answer 4

Change in smell indicator

Question 5

Acid + Metal

Answer 5

Salt + H2

Question 6

Base + Metal

Answer 6

Salt + H2

Question 7

Metal + carbonate

Answer 7

Salt + Co2 + H20

Question 8

Metal + bicarbonate

Answer 8

Same as carbonate

Question 9

What is neutralisation

Answer 9

Reaction bw acid and base
Gives off salt and water

Question 10

Acid + Metal oxide - basic

Answer 10

Salt + H20

Question 11

Base + metal oxide

Answer 11

Same as base and acid

Question 12

Similarities bw acid and bases

Answer 12

Same chemical properties
Acids contain H ions
Base OH ions

Question 13

Acid and bases in water sol

Answer 13

Sep of h + ions cannot happen in absence of water
H + cannot exist alone they exist after combining w water molecules

Base in water generate Oh- ions
These are alkalis

Question 14

Warnings of dissolving acid or base i water

Answer 14

Highly exothermic causes burns glass may break

Decreases conc of ions per unit volume - dilution
Why? H+ ions cannot exist alone

Question 15

How do we know if a sol is strong?

Answer 15

Amt of ions determine it
Shows diff colours at diff conc of H+ ions - Ph scale

Higher hydronium ions lower ph value

Question 16

Strong acids
Weak acids
Strong bases
Weak bases

Answer 16

More h+ ions
Vice versa
More OH - ions
Vice versa

Question 17

Ph values of rain water and our body

Answer 17

5.6
7 to 7.8

Question 18

Acids in other planets

Answer 18

Atmos of venus - thich white and yellowish clouds of sulphuric acid

Question 19

Explain PH of soil and digestive system

Answer 19

Specific range for healthy growth
Colect soil and check

Digestive system - stomach HCl for digestion

Question 20

Tooth decay
Bee sting

Answer 20

Less than 5.5
Bacteria in mouth produce acid by degrading sugar
Leads to corrosion

Prevention - brushing

Bee sting - acids cause pain , stinging hair lraves mathanoic acid
Use baking soda

Question 21

Why are large crustals brown

Answer 21

Due to impurities

Question 22

Hoe are rock salts formed

Answer 22

Formed when seas of bygone ages dry up

Question 23

What happens when electricity is passed thru NaCl

Answer 23

Chlor alkali
Products chlorine gas, h2 gas, NaCl

Question 24

Bleaching powder

Answer 24

Ca0cl2
Action of chlorine on dry slaked lime
Ca(0h2)+ cl2 = Ca0cl2 + h20

Uses
Bleaching of cotton, woodpulp, washed clothes
Oxidising agent
Drinking water free frm germs

Question 25

Baking soda

Answer 25

Uses in kitchen for faster cooking Sodium bicarbonate Non corrosive basic salt - used to neutralise acid Uses Baking powder When its heated NaHco3 + H+ = Co2 + h2o + sodium salt of acid Co2 is produced during this used in bread Soda acid fire extinguisher

Question 26

Washing soda

Answer 26

Na2c03.10h20 Basic salt Na2c03 + 10h20 Uses Glass, soap, paper industries Borax Removing hardness of h20

Question 27

What happens to cuso4 when removed of water

Answer 27

Turns white When mosituned colour reappers

Question 28

What is water of crystallisation

Answer 28

Fixes no. Of water molecules present in 1 formula unit of salt

Question 29

Explain plaster of paris

Answer 29

Obtained frm gypsum - Cas04 .2h20 On heating plaster of oaris at 373k loses h20 mol turns to calcium hemihydrate Uses Fractured bones , toys, surface smoothing

Question 30

Effloresence

Answer 30

Evaporation of water will take place when salt is left in the open