Question

The human blood contains more $[{{\text{H}}^ + }]$ ions than water at a temperature. If true, write $1$, else write$0$.

Answer 1

Hint: We have to compare the hydrogen ion concentration of blood and water at the same temperature, so we will determine the hydrogen ion concentration by using pH formula. Generally we know the pH of water and blood at room temperature, so, we will compare the hydrogen ion concentrations of blood and water at room temperature.

Complete step-by-step answer:
We have to consider the blood and water at the same temperature, so we consider room temperature. At room temperature the pH of water is $7$and pH of blood is $7.35$.
Now we will determine the hydrogen ion concentration as follows:
Now, the formula of pH is as follows:
${\text{pH}}\, = \, - \log \,\left[ {{{\text{H}}^ + }} \right]$
For water,
On substituting $7$ for pH,
${\text{7}}\, = \, - \log \,\left[ {{{\text{H}}^ + }} \right]$
$\,\left[ {{{\text{H}}^ + }} \right]\, = \,{\text{1}}{{\text{0}}^{ - {\text{7}}}}$
For blood,
On substituting $7.35$ for pH,
${\text{7}}{\text{.35}}\, = \, - \log \,\left[ {{{\text{H}}^ + }} \right]$
$\,\left[ {{{\text{H}}^ + }} \right]\, = \,{\text{1}}{{\text{0}}^{ - {\text{7}}.35}}$
So, the hydrogen ion concentration in water at room temperature is ${\text{1}}{{\text{0}}^{ - {\text{7}}}}$ whereas the hydrogen ion concentration in blood at room temperature is ${\text{1}}{{\text{0}}^{ - {\text{7}}{\text{.35}}}}$ so, we can say that the hydrogen ion concentration is more in water than blood at room temperature.
So, the statement, human blood contains more $[{{\text{H}}^ + }]$ ions than water at a temperature is false.

Therefore, the statement is not true, so we will write $0$.

Note: At room temperature, water contains more hydrogen ions than blood so, water has less pH than blood. The hydrogen ion concentration and pH are inversely related and the hydrogen ion concentration and acidity is directly related, so the water is more acidic at room temperature. The hydrogen and hydroxide concentration are related as follows:
$[{{\text{H}}^ + }{\text{]}}[O{{\text{H}}^ - }{\text{]}}\,{\text{ = }}\,{\text{1}}{{\text{0}}^{ - 14}}$
So, as the blood has low concentration of hydrogen ion at room temperature it will have high concentration of hydroxide ion. The hydroxide ions concentration is directly proportional to the pH. So, the blood is basic.