TIME REMAINING 52:03 Considering the activity series given below for metals and nonmetals, which reaction will occur? Al > Mn > Zn > Cr > Fe > Cd > Co > Ni > Sn > Pb > H > Sb > Bi > Cu > Ag > Pd >Hg > Pt F > Cl > Br > I

2NaBr + I2 Right arrow. 2NaI + Br2

2Fe + Al2O3 Right arrow. 2Al + Fe2O3

2AgNO3 + Ni Right arrow. Ni(NO3)2 + 2Ag

Pb + Zn(C2H3O2)2 Right arrow. Zn + Pb(C2H3O2)2

2NaBr + I2 Right arrow. 2NaI + Br2

2AgNO3 + Ni Right arrow. Ni(NO3)2 + 2Ag

Explanation:

The activity or electrochemical series is an arrangement of elements according to their order

of reactivity.

If we look at the reactions, one thing that we must note is that the reactions that can occur are those in which an element that is higher in the series displaces another element that is lower in the series.

Br is higher in the electrochemical series than I so it can displace it. Ni is higher than Ag in the electrochemical series hence it can displace it.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2