lesson 1.. unit 1.. chemical reaction

On heating copper carbonate.. the colour change from...........

• Blue to black

• Green to black

• Black to green

• Green to blue

Carbon dioxide evolves during the thermal decomposition of .............. compound

• HgO

• CuSo₄

• CuCo₃

• Cu (oH)₂

Active metals react with water as they substitute hydrogen of water forming ............ and hydrogen gas evolves

• Metal oxides

• Metal nitrates

• Metal hydroxides

• Metal nitrites

All of the following metals replace hydrogen of acid except.......

• Sn

• Au

• Zn

• Al

When magnesium replaces the copper in its salt solition, a .............. precipitate is formed

• Red

• Black

• Blue

• Green

Substitution reaction between acid and alkali produce........

• Acid oxide and hydrogen gas

• Salt and water

• Metal carbonate and carbon dioxide

• Salt and hydrogen gas evolves

The oxidizing agent is the substance which .............. during the chemical reaction

• Gives oxygen

• Removes hydrogen

• Loses hydrogen

• A and B