The ph of saliva is normally in the range of 6.4 to 7.0. however, when a person is ill, the person's saliva becomes more acidic. (a) when marco is sick, he tests the ph of his saliva and finds that it is 5.3. what is the hydrogen ion concentration of his saliva

Concentration of hydrogen ion,

Explanation:

pH is defined as the negative logarithm of hydrogen ion's concentration.

The lower the value of pH, the higher the acidic the solution is.

The formula for pH can be written as:

Given,

pH of the saliva of Marco = 5.3

To calculate: Hydrogen ion concentration in the saliva

Thus, applying in the formula as:

So,

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.