Question

how to find delta ng in details

Answer 1

delta n is the sum of the coefficients of the gaseous products minus the sum of the coefficients of the gaseous reactants. The reaction quotient, Q, is an expression which deals with initial values instead of the equilibrium value that K deals with.
Hope it will help you

Answer 2

Delta ng of an equation is simply the difference between the number of gaseous molecules of products and the number of gaseous molecules of reactants. The relationship is as follows: Delta ng of an equation = number of gaseous molecules of products - number of gaseous molecules of reactants.