Advertisements
Advertisements
प्रश्न
With reference to Water explain with suitable examples of how the reactivity of the metals could be differentiated.
Advertisements
उत्तर
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
संबंधित प्रश्न
What do you observe when dilute sulphuric acid is added to granulated zinc?
What do you observe when a few pieces of iron are dropped in a blue solution of copper sulphate?
How will you obtain Zinc chloride from zinc.
Also give balanced equations for the reactions
What do you observe when magnesium ribbon is burnt in oxygen?
Divide the metals Cu, Zn, Ca, Mg, Fe, Na, Li into three groups, namely reactive metals, moderately reactive metals and less reactive metals.
Give a balanced equation for the reversible catalytic reaction involving nitrogen as one of the reactants.
Explain the following reaction with the balanced equation.
Magnesium reacts with dil HCl
Observe the following diagram and identify the type of reaction and write observation.
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.
Three metal samples of magnesium, aluminium and iron were taken and rubbed with sandpaper. These samples were then put separately in test tubes containing dilute hydrochloric acid. Thermometers were also suspended in each test tube so that their bulbs dipped in the acid. The rate of formation of bubbles was observed. The above activity was repeated with dilute nitric acid and the observations were recorded.
Answer the following questions:
(i) When the activity was done with dilute hydrochloric acid, then in which one of the test tubes was the rate of formation of bubbles the fastest and the thermometer showed the highest temperature?
(ii) Which metal did not react with dilute hydrochloric acid? Give reason.
(iii) Why is hydrogen gas not evolved when a metal reacts with dilute nitric acid? Name the ultimate products formed in the reaction.
OR
Name the type of reaction on the basis of which the reactivity of metals is decided. You have two metals X and Y. How would you decide which is more reactive than the other?
