Question

balance equation by only ABCD METHOD ..DONT USE HIT AND TRIAL METHOD​

Answer 1

Explanation:

Given -

• S + HNO3 → H2SO4 + NO2 + H2O

To Find -

• Balance it

• → a S + b HNO3 → c H2SO4 + d NO2 + e H2O

→ S :- a = c ..... (i)

• Here, In product side there is one S and also in reactant side there is one S. So, here we write the cofficient of S atoms. In reactant side, cofficient of S is a and in product side cofficent of S is c (In product side S is present in H2SO4)

N :- b = d ..... (ii)

• Here, In product side there is one N and also in reactant side there is one N. So, here we write the cofficient of N atoms. In reactant side, cofficient of N is b and in product side cofficent of N is d (In product side N is present in NO2 and in reactant side N is present in HNO3)

O :- 3b = 4c + 2d + e ...... (iii)

• Here, In product side there is four O in H2SO4, two O in NO2 and one O in H2O and also in reactant side there is three O. So, here we write the cofficient of O atoms. In reactant side, cofficient of O is 3b and in product side cofficent of O is 4c + 2d + e (In product side O is present in H2SO4, NO2 and H2O and in reactant side oxygen is present in HNO3)

H :- b = 2c + 2e .... (iv)

• Here, In product side there is two H in H2SO4 and two H in H2O and also in reactant side there is one H. So, here we write the cofficient of H atoms. In reactant side, cofficient of H is b and in product side cofficent of H is 2c + 2e (In product side H is present in H2SO4 and H2O and in reactant side H is present in HNO3)

Let a = 1

Then, c = 1 (bcoz a = c)

It is cleared that b = d and a = c

Then,

→ 3b = 4c + 2d + e

→ 3d - 2d = 4a + e

d = 4a + e ..... (v)

And

→ b = 2c + 2e

→ d = 2a + 2e ..... (vi)

Now, From solving (v) and (vi), we get :

By Elimination method :-

→ [ d = 4a + e ] × 2

[ d = 2a + 2e ]

→ 2d = 8a + 2e

d = 2a + 2e

(-) (-) (-)

_____________

→ d = 6a

→ d = 6 × 1

d = 6

Now,

→ d = 2a + 2e

→ 6 = 2×1 + 2e

→ 4 = 2e

e = 2

Hence,

a = 1

b = 6 (bcoz b = d)

c = 1 (bcoz a = c)

d = 6

e = 2

And

The balanced chemical equation :-

• 1S + 6HNO3 + 1H2SO4 + 6NO2 + 2H2O