Advertisements
Advertisements
Question
With reference to Water explain with suitable examples of how the reactivity of the metals could be differentiated.
Advertisements
Solution
Action of metals with water: K, Na, Ca react with cold water.
K: Darts on the water surface and react violently.
Na: Revolves on the water surface and bums.
Ca: Sinks in water, react less violently.
Hence, K > Na > Ca calcium is less reactive than K and Na.
Mg and Al react with boiling water/steam.
Hence, Mg and Al are less reactive than K, Na, and Ca. Zn, Fe, Pb also react with steam and reaction stops soon. Fe when hot reacts with steam
This shows that Mg > Al > Zn > Fe > Pb.
Cu, Hg, Ag, Pt, Au do not react with steam or even when hot is less reactive.
APPEARS IN
RELATED QUESTIONS
What do you observe when dilute sulphuric acid is added to granulated zinc?
What do you observe when ferrous sulphate solution is added to an aqueous solution of sodium hydroxide.
How will you obtain Zinc chloride from zinc.
Also give balanced equations for the reactions
Write chemical equation for the event.
Aluminium came in contact with air.
State what is meant by the ‘reactivity series of metals’
With reference to Acid explain with a suitable example of how the reactivity of the metals could be differentiated.
A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with HCl and NaOH.
A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reaction involved.
Explain the following
- Reactivity of Al decreases if it is dipped in HNO3
- Carbon cannot reduce the oxides of Na or Mg
- NaCl is not a conductor of electricity in solid state whereas it does conduct electricity in aqueous solution as well as in molten state
- Iron articles are galvanised.
- Metals like Na, K, Ca and Mg are never found in their free state in nature.
Metal ‘A’ has electronic configuration 2, 8, 1 and metal ‘B’ has electronic configuration 2, 8, 8, 2. Out of these, which metal is more reactive? Write the reaction of this metal with dilute HCl acid.
