Comprehensive pH Scale Chart: pH Values for Common Substances

pH Value

What is pH? In chemistry, pH stands for “potential of hydrogen.” It is a quantitative metric used to define the acidity or alkalinity of an aqueous solution. The pH scale, ranging from 0–14, measures the concentration of hydrogen ions. A pH value below 7 is acidic, while a pH level of exactly 7 is neutral, and a value above 7 indicates an alkaline (basic) substance. The litmus test is a common indicator for these properties: blue litmus paper turns red in acidic solutions, while red litmus paper turns blue in basic ones.

pH Values List

As a measure of hydrogen ion concentration, the pH value dictates the chemical nature of a solution. As the pH value drops below 7, acidity increases; conversely, as the pH value rises above 7, alkalinity increases. Refer to the table below for a complete list of chemical substances and their respective pH values.

GK Questions Related to pH Values

The pH scale provides a standardized range from 0 to 14 to categorize substances as acidic, neutral, or basic. To better understand these measurements, we have compiled the typical pH values for common substances like acid rain, human blood, common salt, milk, and saliva. You can also test your knowledge with these GK Questions focused on pH values provided in the section below.

Q1. What is the pH Value of acid rain?

Ans. Acid rain typically has a pH between 5.0 and 5.5, making it acidic. This occurs when atmospheric rain reacts with pollutants like sulfur dioxide or nitrogen oxides emitted by industrial power plants and vehicles.

Q2. What is the pH Value of Blood?

Ans. The pH of human blood is tightly regulated between 7.34 and 7.45, making it slightly alkaline. If blood pH rises above this range, it leads to a condition known as alkalosis; if it drops, it results in acidosis.

Q3. What is the pH Value of Pure Drinking Water?

Ans. Pure, distilled water has a pH of 7.0, marking it as chemically neutral.

Q4. What is the pH value of milk?

Ans. Fresh milk generally features a pH level between 6.5 and 6.7, classifying it as slightly acidic.

Q5. What is the pH value of Gastric Juice?

Ans. Gastric juice is highly acidic, with a pH ranging from 1.0 to 3.5. It contains hydrochloric acid (HCl), lipase, and pepsin, which work together to break down food and neutralize harmful microorganisms.

Q6. What is the pH value of Saliva?

Ans. The pH of human saliva ranges from 6.2 to 7.6. Saliva plays a vital role in oral health by neutralizing bacterial acids and washing away food particles.

Q7. What is the pH Value of Lemon Juice?

Ans. Lemon juice is quite acidic, with a pH ranging from 2.2 to 2.4. This acidity is due to a high concentration of hydronium ions.

Q8. What is the pH Value of Urine?

Ans. Urine is a waste product of the body, and its pH can vary significantly, typically ranging from 4.5 to 8.0 depending on diet and metabolic health.

Q9. What is the pH Value of Vinegar?

Ans. Vinegar typically has a pH between 2.0 and 3.0, characterizing it as a mildly acidic solution.

Q10.  What is the pH Value of Battery Acid?

Ans. Battery acid is highly corrosive, with a pH of approximately 1.0. It usually contains sulfuric acid, which is essential for the chemical reactions that generate electric current.

Q11. What is the pH Value of Tomato Juice?

Ans. Tomato juice has a pH of about 4.0. Its acidity is derived from natural organic acids like citric, ascorbic, and malic acid.

Q12. What is the pH value of Salt?

Ans. Common table salt is neutral with a pH of 7. Because it is formed from a strong acid and a strong base, it does not undergo hydrolysis.

Q13. What is the pH value of Alcohol?

Ans. Alcohol (ethanol) generally has a pH near 7.33. It is often described as amphiprotic, as the bond between the carbon and hydroxyl groups is only slightly polar, preventing it from being classified as a strictly strong acid or base.

Q14. What is the pH value of Baking soda?

Ans. Baking soda, or sodium bicarbonate, is basic in nature with a pH of approximately 9.

Q15. What is the pH value of Bleaching Powder?

Ans. Bleaching powder is strongly basic with a pH of 11. When it reacts with hydrochloric acid, it releases chlorine gas alongside calcium chloride and water.