Question

Answer

Answer 1

a)

Before any HCl is added, solution contains only base.

So, pH would be greater than 7

Answer: pH > 7

b)

mol of NH3 = M(NH3)*V(NH3)

= 0.300 M * 0.070 L

= 0.021 mol

mol of HCl = M(HCl)*V(HCl)

= 0.500 M * 0.042 L

= 0.021 mol

Equal mol of acid and base has been added

So, both will react and form NH4Cl which is weak acid

So, pH will be less than 7

Answer: pH < 7

C)

More HCl has been added than NH3

So, pH would be less than 7

Answer: pH < 7