Chemical equation and reaction

Zn + CuSO4 ---- ZnSO4 + Cu, The type of a above chemical reaction is

• Combination reaction

• Double displacement reaction

• Displacement reaction

• Decomposition reaction

Which of the following is a decomposition reaction

• CaO + H2O --- Ca( OH) 2

• Fe + CuSO4 ------- FeSO4 + Cu

• Na2SO4 + BaCl2 ----- BaSO4 + 2 NaCl

• FeSO4 ------ Fe2O3 + SO2 + SO3

Manasa burnt a piece of Magnesium ribbon and she observed

• Magnesium burns with blue flame and give black coloured ash

• Magnesium burns with white drizzling flame and give white coloured ash

• Magnesium burns with yellow drizzling flame and give white coloured ash

• Magnesium burns with blue flame and give brown coloured ash

The gas liberated at the cathode in the electrolysis of water is

• Hydrogen

• Oxygen

• Chlorine

• Nitrogen

Oxidation of fats and oil is called

• Rusting

• Corrosion

• Rancidity

• Decaying

Galvanisation is a process in which

• Silver coating is given to iron

• Zinc coating is given to copper

• Zinc coating given to iron

• Aluminium coating given to iron

When a copper is exposed to air for a long time it acquire a green coat because it reacts with

• Sulphur

• Nitrogen

• Moist oxygen

• Moist carbon dioxide

Chips manufacturers flush bag of chips with nitrogen gas because

• Prevent corrosion of chips

• Prevent chips from getting oxidized

• Make chips undergo rancidity

• Prevent chips from getting reduced

The reactants that exchange ions by reacting with each other to form a precipitate among the following are

• BaCl2 and NaSO4

• Al2O3 and HCl

• NaOH and H2SO4

• Na2O and CO2

When a solution of sodium sulphate and a solution of barium chloride is mixed, the colour of precipitate formed

• Black

• White

• Yellow

• Blue