Question

Which reaction will occur? 2NaBr + I2 mc023-1.jpg 2NaI + Br2 2Fe + Al2O3 mc023-2.jpg 2Al + Fe2O3 2AgNO3 + Ni mc023-3.jpg Ni(NO3)2 + 2Ag Pb + Zn(C2H3O2)2 mc023-4.jpg Zn + Pb(C2H3O2)2

Answer 1

Answer:- $2AgNO_3+Ni\rightarrow Ni(NO_3)_2+2Ag$ reaction will occur as Ni is more reactive than Ag.

Explanations:- The given reactions are:

a) $2NaBr+I_2\rightarrow 2NaI+Br_2$

b) $2Fe+Al_2O_3\rightarrow Fe_2O_3+2Al$

c) $2AgNO_3+Ni\rightarrow Ni(NO_3)_2+2Ag$

d) $Pb+Zn(C_2H_3O_2)_2\rightarrow Zn+Pb(C_2H_3O_2)_2$

It asks which one of these four reactions will occur. We could answer this question on the basis of reactivity series.

"Less reactive element is replaced by the more reactive one but the more reactive element can't be replaced by less reactive element."

Reactivity of non metals like halogens decreases as we move down in a group. It means Bromine is more reactive than iodine and so the first reaction will not occur as being less reactive, iodine is unable to replace bromine from sodium bromide solution.

Reactivity order of Fe, Al, Ag, Ni, Zn and Pb is as follows:

Al>Zn>Fe>Ni>Pb>Ag

Second reaction will also not occur as being less reactive, Iron can not replace aluminum from aluminum oxide.

Third reaction will occur as Nickel is more reactive than silver, so silver can be replaced by nickel from silver nitrate.

Fourth reaction will not occur as Pb is less reactive than Zn and so it would not be able to replace Zn from zinc acetate solution.

Hence, only and only third reaction will occur.

Answer 2

Answer:

C

Explanation: