Question

The ph of a mixture of 100 ml of 1M of H2SO4 and 200ml 1N of Naoh at 25°C is

Answer 1

7 will be the answer I think so because if you find out the concentration h+ ions and oh- ions it will same so pH will be 7 please confirm once I am telling it orally I have not solved

Answer 2

Answer : The pH of a mixture will be, 7

Solution :

The balanced equation will be,

$H_2SO_4+2NaOH\rightarrow Na_2SO_4+2H_2O$

Now we have to calculate the moles of $H_2SO_4$ and NaOH.

$Molarity =\frac{\text{moles of solute}}{\text{Volume of solution in liters}}$

${\text{moles of }H_2SO_4=\text{molarity}\times\text{Volume of solution in liters}}=1M\times 0.1L=0.1moles$

As we know that the $H_2SO_4$ dissociates 2 $H^+$ ion.

So, the number of mole of $H^+$ ion in $H_2SO_4$= 2 × 0.1 = 0.2 moles

${\text{moles of }NaOH=\text{molarity}\times\text{Volume of solution in liters}}=1M\times 0.2L=0.2moles$

As we know that the $NaOH$ dissociates 1 $OH^-$ ion.

So, the number of mole of $OH^-$ ion in $NaOH$= 1 × 0.2 = 0.2 moles

As, 1 mole of $H^+$ ion neutralized by the 1 mole $OH^-$ ion.

So, 0.2 mole of $H^+$ ion neutralized by the 0.2 mole $OH^-$ ion.

As, the solution will be completely neutralized. So, the pH will be 7.

Thus, the pH of a mixture will be, 7