(a) A metal compound X' reacts with dil 1-1SO4 to produce effervescence. The gas evolved extinguishes a burning candle. If one of the compound formed is calcium sulphate, then what is 'X' and the gas evolved ? Also write a balanced chemical equation for the reaction which occurred.
(b) (i) Name one antacid. How does it help to relieve indigestion is stomach ?
(ii) A farmer treats the soil with quick lime or calcium carbonate. What is the nature of soil ? Why
does the farmer treat the soil with quick lime ?
CBSE Class X Science LA (5 Marks)
Answers
a) Metal compound X is CaCO3(Calcium carbonate)
When CaCO3 reacts with H2SO4 it gives the product as CaSO4, H20, CO2.The gas evolved used in extinguishing burning candle is CO2(carbon dioxide).CaSO4 gives efferverence.
Chemical Reaction
CACO3 + H2SO4 - - - - > CaSO4+H20+CO2
b) ¡) The antacid are Milk of Magnesia, NaHCO3(baking soda) and etc.
NaHCO3 or Milk of Magnesia helps to bring relieve by indigestion in stomach as:
In stomach the concentration or amount of acid gets more (HCL) so it causes irritation and acidity within body. NaHCO3 and milk of Magnesia which are basic in nature helps to neutralize the effect of the acid in the stomach and helps prevent us from acidity and irritation.
¡¡) As the farmer is treating a soil with quick lime(CaO) or Calcium carbonate(CaCO3) which are basic in nature than the nature of soil will be acidic as he would treat the soil to neutralize the effect of acid. Hence the nature of soil is acidic.This way the crop won't get destroyed as soil will be neutral.
Answer:
a) metal compound 'x' is CACO3
when CACO3 reats with H2SO4 it gives the product as CASO4,CO2 . the gas evolves used in extinguishing burning candle in CO2 .CASO4 give effervescent .
chemical reactions---
CACO3 +H2SO4--------->CASO4+H2O+CO2.