Advertisements
Advertisements
प्रश्न
Why should a magnesium ribbon be cleaned before it is burnt in the air?
Why should magnesium ribbon be cleaned before burning in the air?
Advertisements
उत्तर
Magnesium ribbon is cleaned with sandpaper before burning to remove the protective layer of magnesium oxide (MgO) that forms on its surface when it reacts with moist air. This oxide layer is stable and prevents or slows down the further burning of the magnesium ribbon. Removing this layer allows the pure magnesium metal to burn easily.
\[\ce{2Mg + O2 -> 2MgO}\]
संबंधित प्रश्न
Write the balanced chemical equation for the following reaction.
\[\ce{Zinc + Silver nitrate -> Zinc nitrate + Silver}\]
On what basis is a chemical equation balanced?
Name the various types of chemical reactions.
Write a balanced chemical equation with state symbols for the following reaction:
Barium chloride solution reacts with sodium sulphate solution to give insoluble barium sulphate and a solution of sodium chloride.
Balance the following equation. Also name the product formed.
K2O + H2O → KOH
Balance the following equation. Also name the product formed.
N2 + H2 → NH3
Balance the following equation. Also name the product formed.
FeCI2 + CI2 → FeCI3
Write the chemical equation for the following word equation and balance them.
Carbon + Oxygen → Carbon dioxide
Balance the following equation:
Pb3O4 → PbO + O2
What information does the following chemical equation convey?
Zn + H2SO4 → ZnSO4+ H2
What is the valency of :
carbon in CH4
Write the balanced chemical equation of the following reaction. sodium hydroxide + sulphuric acid → sodium sulphate + water
(a) Give only one suitable chemical test to identify the following gases.
- Ammonia
- Sulphur dioxide
- Hydrogen Chloride
- Chlorine
- Carbon Dioxide
- Oxygen
- Hydrogen
(b) Select a basic gas mentioned in Q.1 (a). How is the basic nature suspected?
(c)Select acidic gases from the gases mentioned in Q.1 (a). How is the acidic nature suspected?
(d) State the gas responsible for bleaching action.
(e)Which gas turn blue cobalt chloride paper light pink?
Considering the relationship in the first pair, complete the second paie :
AgCI : White :: CuI2 : ___________
Write word equation for the following chemical reaction given below. Also state the observation seen in the case.
\[\ce{2SO2 + O2 ⇌[V2O5][450°C] 2SO3}\]
Balance the following simple equation:
FeCl2 + Cl2 → FeCl3
Write a balanced equation for the following word equation:
Nitrogen dioxide + Water + Oxygen → Nitric acid
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
CaC2 + N2 → 2CaCN2 + C
Underline the compound in the equation given below, it is incorrectly balanced and write the correct balancing for the same.
Cl2 + 2H2O + SO2 → 4HCl + H2SO4
What is a reactant in a chemical equation?
