Chemical Reactions and Equation (UP)

Select the oxidising agent for the following reaction:
H₂S + I₂ --------> 2HI + S

• (a) I₂

• (b) H₂S

• (C) HI

• (d) S

A substance added to food containing fats and oils is called:

• (a) Oxidant

• (b) Rancid

• (c) Coolant

• (d) Antioxidant

Pb + CuCl₂ → PbCl₂ + Cu
The above reaction is an example of:

• (a) combination

• (b) double displacement

• (c) decomposition

• (d) displacement

Which of the following is an endothermic process?

• (a) Dilution of sulphuric acid

• (b) Sublimation of dry ice

• (c) Condensation of water vapours
  

• (d) Respiration in human beings

When Ag is exposed to air it gets a black coating of

• (a) AgNO₃

• (b) Ag₂S

• (c) Ag₂O

• (d) Ag₂CO₃

A substance ‘X’ is used in white-washing and is obtained by heating limestone in the absence of air. Identify ‘X’.

• (a) CaOCl₂

• (b) Ca (OH)₂

• c) CaO

• (d) CaCO₃

MnO₂ + 4HCl → ₂ + 2H₂O + Cl₂
Identify the substance oxidized in the above . equation.

• (a) MnCl₂

• (b) HCl

• (c) H₂O

• (d) MnO₂

The process of reduction involves

• addition of oxygen

• removal of hydrogen

• addition of hydrogen

• None of these

Which of the following is a chemical change?

• a) Melting of ice

• b) Dissolving sugar in water

• c) Boiling water

• d) Rusting of iron

The balanced chemical equation for the reaction between hydrogen and oxygen to form water is:

• a) H₂ + O₂ → H₂O

• b) 2H₂ + O₂ → 2H₂O

• c) H₂O → H₂ + O₂

• d) 2H₂O → 2H₂ + O₂