Question

the average human contains 5.0 liters of blood having a pH of 7.35. calculate the number of moles of H3O+ at 25 degree celsius

Answer 1

Answer : The number of moles of hydronium ion is, $2.2\times 10^{-7}mole$

Explanation :

First we have tom calculate the concentration of hydrogen ion or hydronium ion.

pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.

$pH=-\log [H_3O^+]$

Given:

pH = 7.35

$7.35=-\log [H_3O^+]$

$[H_3O^+]=4.47\times 10^{-8}mol/L$

Now we have to calculate the moles of hydronium ion.

$\text{Moles of }H_3O^+=\text{Molarity of }H_3O^+\times \text{Volume of solution}$

Now put all the given values in this expression, we get:

$\text{Moles of }H_3O^+=(4.47\times 10^{-8}mol/L)\times (5.0L)$

$\text{Moles of }H_3O^+=2.2\times 10^{-7}mole$

Therefore, the number of moles of hydronium ion is, $2.2\times 10^{-7}mole$