562 Balance the following equations and classify each as a p

5.62 Balance the following equations and classify each as a precipitation, neutralization, or redox reaction: (a) Al ( OH )3(aq) + HNO3(aq)-> Al (NO3)3(aq) + HO(l) (b) AgNO3(aq) + FeCl3(aq)- AgCl(s) + Fe(NO3)3(aq) (c) (NH4)2Cr0,(s) Cro0s(s) + H,0(8) + N2(8) (d) Mn2(CO;)3(s) Mn,0;(s) + CO2(8)

Solution

a)

Al(OH)3(aq)   + HNO3(aq) ------------------------ Al(NO3)3(aq) + H2O(l)

Al(OH)3(aq)   +3 HNO3(aq) ------------------------ Al(NO3)3(aq) + 3 H2O(l)

This is neutralisation reaction becuase Al(OH)3 is a base and HNO3 is an acid and reacts with each other to give H2O.

b)

Ag(NO3)(aq) + FeCl3(aq) --------------- AgCl(s)   + Fe(NO3)3(aq)

3 Ag(NO3)(aq) + FeCl3(aq) --------------- 3 AgCl(s)   + Fe(NO3)3(aq)

3 Ag+(aq) +3 NO3-(aq) + Fe+3(aq) + 3 Cl-(aq) --------------- 3 AgCl(s) + F3+3(aq) + 3 NO3(aq)

3 Ag+(aq) + 3 Cl-(aq) -------------- 3 AgCl(s)

so it is the precipitation reaction

c)

(NH4)2Cr2O7(s) ------------------- Cr2O3(s) + H2O(g)     + N2(g)

(NH4)2Cr2O7(s) ------------------- Cr2O3(s) + 4 H2O(g)     + N2(g)

(NH4)2Cr2O7 ------------- NH4+ + Cr2O7-2

In NH4+ the oxidation state of N is -3               x+4(+1) = +1 ========== x=-3

IN N2 , the oxidation of N is 0(zere)

so it undergoes oxidation

In Cr2O7-2 , the oxidation state of Cr is +6         2x + 7(-2) = -2 ============== x= +6

In Cr2O3, the oxidation state of Cr is +3            2x+3(-2)= 0 =============== x= +3

so Cr undergoes reduction

so Oxidation and reduction takesplace ina reaction .\\Hence it is redox reaction.

d)

Mn2(CO3)3 (s) ---------------- Mn2O3(s) + CO2(g)

Mn2(CO3)3 (s) ---------------- Mn2O3(s) + 3 CO2(g)

It is a redox reaction