The value of n for the following reaction will be :

NH4Cl(s)NH3(g)+HCl(g)

1. 1

2. 0.5

3. 1.5

4. 2

Hint: ng =  number of gaseous molecules of products - number of gaseous molecules of reactants.
Step 1:
The relationship between Kc and Kp is
Kp=Kc(RT)n
where, n=(number of moles of gaseous products)-(number of moles of gaseous reactants)
Step 2:
For solid-state reactants or product number of moles is constant and we did not include it.
For the reaction,
NH4Cl(s)NH3(g)+HI(g)n=2-0=2