Question

What volume of 3.00 M HCl will form a solution with a basic pH when mixed with 100 mL of 3.00 M NaOH?

a)101 mL

b)100 mL

c)150 mL

d)50.0 mL

Answer 1

d)50.0 mL

Step-by-step explanation:

At equivalence point ,

Moles of
`HCl` = Moles of NaOH

Considering :-

`Molarity_(HCl)* Volume_(HCl)=Molarity_(NaOH)* Volume_(NaOH)`

Given that:

`Molarity_(NaOH)=3.00\ M`

`Volume_(NaOH)=100\ mL`

`Volume_(HCl)=?\ mL`

`Molarity_(HCl)=3.00\ M`

So,

`Molarity_(HCl)* Volume_(HCl)=Molarity_(NaOH)* Volume_(NaOH)`

`3.00* Volume_(HCl)=3.00* 100`

`Volume_(HCl)=(3.00* 100)/(3.00)\ mL=100\ mL`

The volume of HCl at equivalence point is - 100 mL

More addition of the acid forms a acidic solution. Thus, d)50.0 mL is the correct option because all other options are greater or equal to 100 which leads to acidic or neutral solution respectively.