Q1
What happens when water is added in quick lime
Write chemical eqn
Q2
What is the colour of crystal of ferrous sulphate and copper sulphate
Write their chemical formula
Q3.
What happens when ferrous sulphate is heated strongly
Write chemical eqn
Q4.
What happens when lead nitrate is heated. Write chemical eqn
Q5.
Why do we add sulphuric acid in water during electrolysis of it
Q6.
What happens when electricity is passed through it
What is volume ratio of hydrogen and oxygen gas evolved during electrolysis of it
Write balance chemical eqn
pl answer fast
Answers
Answer:
When Calcium oxide i.e. quick lime is added to water filled in a bucket, it reacts vigorously with water to produce slaked lime (calcium hydroxide) releasing a large amount of heat. When HCl reacts with an active metal,hydrogen gas is liberated
Answer:
Ans 1: The chemical formula of quick lime is CaO. The reaction which takes place when quicklime is added to water is as follows:
CaO+H2O→Ca(OH)2
From the above reaction we can say that, when quick lime is added to water then, formation of slaked lime precipitate takes place.
Ans 2: The ferrous sulphate crystals are light green. Ferrous sulphate is also obtained as a by-product in the manufacture of titanium pigment and copper sulphate. Chemical formula: FeSO4
The crystals of hydrated copper sulphate salt are blue in colour. When heated, the salt loses its water of crystallization and turns white. Chemical formula: CuSO4.
Ans 3: On heating, ferrous sulphate crystals lose water and anhydrous ferrous sulphate (FeSO4) is formed. So their colour changes from light green to white. On further heating, anhydrous ferrous sulphate decomposes to form ferric oxide (Fe2O3), sulphur dioxide (SO2) and sulphur trioxide (SO3).
Ans 4: When lead(II) nitrate is heated, it decomposes into lead (II) oxide, nitrogen dioxide and oxygen. The balanced chemical equation for this reaction is 2 Pb(NO3)2 (s) produces 2 PbO (s) + 4NO2 + O2 (g). 2Pb(NO3)2 = 2PbO + 4NO2 + O2.
Ans 5: To increase the conductivity of water a few drops of sulphuric acid is added . Being a strong acid it can ionize completely to release H+ ions. These H+ ions are responsible for the conduction of electricity. To carry out electrolysis in water,a few drops of sulphuric acid is added to the water.