Question

thin strips of magnesium, copper and iron are taken. write down what happens when these metals are treated as follows: heated in presence of air, heated with dilute sulphuric acid and added to an aqueous solution of zinc sulphate. and arrange these metals in descending order of reactivity.

Answer 1

The reaction of Magnesium, Copper, and Iron:

1. Heated in the presence of air:

• All the elements form oxides when they are heated in the presence of air.
• The equation involved in the reaction is as follows:

$M g+O_{2} \rightarrow M g O$

$F e+O_{2} \rightarrow F e_{2} O$

$C u+O_{2} \rightarrow C u O$

2. Heated with dilute sulfuric acid

• As copper is less reactive than hydrogen, it doesn't react with dil HCl, whereas magnesium and iron being more reactive than hydrogen forms respective salt and liberates hydrogen gas with dil HCl.
• The reaction involved is as follows:

$Mg+2HCl\rightarrow MgCl_2+H_2$

$Fe+HCl\rightarrow FeCl_2+H_2$

3. Added with an aqueous solution of zinc sulfate:

• As copper is less reactive than zinc, only magnesium reacts with zinc sulfate and forms the following product.

$Mg+ZnSO_4\rightarrow Mg_2SO_4+Zn$

4. Arrangement of elements bases on decreasing order of reactivity:

• The given elements when arranged based on descending order of reactivity, it gives

Mg>Fe>Cu

Learn more about such concept

On the basis of the reactivity series of metals, predict how these metal will react with each of the following salt solutions. Metals: magnesium, zinc, copper, Iron, and potassium Salt solutions: magnesium sulphate, zinc sulphate,copper sulphate, iron sulphate, and potassium sulphate.

https://brainly.in/question/1605649

Arrange the following metals in order of increasing reactivity - Cu,K,Fe,Ag,Ca,Na,Zn,Au

https://brainly.in/question/5698309

Answer 2

Answer:

1.forms oxides

2.liberates hydrogen and forms their respective salts

b. mg>fe>cu