Question

1. The enthalpy of reaction N2 + 3H2 gives 2NH3, was found to be -91.97 kJ what will be the enthalpy of reaction at 323 K. The molar heat capacity at constant pressure and 300 K for nitrogen, hydrogen and ammonia or 28.46, 28.33 and 37.08 J K-1 mol-1 respectively​

Answer 1

Explanation:

GiveN:-

A father is 7 times as old as his son, two years ago the Father was 13 times as old as his son.

To FinD:-

The present age of son.

SolutioN:-

Let the present age of the son be x years.

Let the present age of the father be 7x years.

2 years ago their ages were:-

Son = (x - 2) years.

Father = (7x - 2) years.

It is said that two years ago the Father was 13 times as old as his son.

According to the question,

\large\implies{\sf{7x-2=13(x-2)}}⟹7x−2=13(x−2)

\large\implies{\sf{7x-2=13x-26}}⟹7x−2=13x−26

\large\implies{\sf{-2+26=13x-7x}}⟹−2+26=13x−7x

\large\implies{\sf{24=6x}}⟹24=6x

\large\implies{\sf{\dfrac{24}{6}=x}}⟹

6

24

=x

\large\implies{\sf{\dfrac{\cancel{24}}{\cancel{6}}=x}}⟹

6

24

=x

\large\implies{\sf{4=x}}⟹4=x

\large\therefore\boxed{\bf{x=4.}}∴

x=4.

Their present ages:-

Son's age = x = 4 years.

Father's age = 7x = 7 × 4 = 28 years.

The present age of the son is 4 years.