- 1. Acids and bases are two important classes of compounds in chemistry that play crucial roles in various chemical reactions and processes. Acids are substances that release hydrogen ions (H+) when dissolved in water, leading to a decrease in pH levels. They are known for their sour taste, ability to turn blue litmus paper red, and their corrosive properties. On the other hand, bases are substances that release hydroxide ions (OH-) when dissolved in water, resulting in an increase in pH levels. Bases have a bitter taste, feel slippery to the touch, and are known for their ability to turn red litmus paper blue. Acids and bases often react with each other in what is known as neutralization reactions, forming water and a salt. The concept of pH is used to measure the acidity or basicity of a substance, with acidic substances having a pH below 7, neutral substances having a pH of 7, and basic substances having a pH above 7. Understanding acids and bases is essential in fields such as biochemistry, environmental science, and many industrial processes.
A substance with a pH of 9 is classified as:
A) Acidic
B) Alkaline
C) Base
D) Neutral
- 2. What is the pH of a neutral solution?
A) 1
B) 14
C) 4
D) 7
- 3. Which of the following is a common base?
A) Sodium hydroxide
B) Citric acid
C) Carbonic acid
D) Sulfuric acid
- 4. Which acid is found in lemons?
A) Sulfuric acid
B) Acetic acid
C) Nitric acid
D) Citric acid
- 5. Ammonia solution turns red litmus paper:
A) Yellow
B) Purple
C) Blue
D) Green
- 6. Which acid is commonly found in vinegar?
A) Sulfuric acid
B) Hydrochloric acid
C) Acetic acid
D) Nitric acid
- 7. The pH scale ranges from:
A) 0 to 14
B) 1 to 10
C) 0 to 12
D) 5 to 15
- 8. A solution with a pH of 2 is classified as:
A) Alkaline
B) Basic
C) Acidic
D) Neutral
- 9. Baking soda is a common name for:
A) Citric acid
B) Phosphoric acid
C) Sodium bicarbonate
D) Sulfuric acid
- 10. Which acid is commonly found in batteries?
A) Hydrochloric acid
B) Acetic acid
C) Sulfuric acid
D) Nitric acid
- 11. What color does blue litmus paper turn when in contact with an acid?
A) Yellow
B) Blue
C) Green
D) Red
- 12. A substance with a pH of 7 is classified as:
A) Basic
B) Neutral
C) Acidic
D) Alkaline
- 13. Which of the following is an example of a weak base?
A) Sodium hydroxide
B) Ammonia
C) Potassium hydroxide
D) Calcium hydroxide
- 14. What is the product of a reaction between an acid and a base?
A) Hydrogen gas
B) Carbon dioxide
C) Oxygen gas
D) Salt and water
- 15. Which acid is naturally found in milk?
A) Acetic acid
B) Sulfuric acid
C) Hydrochloric acid
D) Lactic acid
- 16. What happens when an acid reacts with a base?
A) Neutralization
B) Sublimation
C) Oxidation
D) Combustion
- 17. Acids donate ________ in a chemical reaction.
A) Photons
B) Neutrons
C) Electrons
D) Protons
- 18. What is the chemical formula of hydrochloric acid?
A) HCl
B) NaOH
C) CO2
D) H2O
- 19. What is the role of a buffer solution?
A) Resists changes in pH
B) Acts as a catalyst
C) Increases pH
D) Decreases pH
- 20. A solution with a pH of 9 is classified as:
A) Basic
B) Alkaline
C) Acidic
D) Neutral
- 21. What substance is produced when an acid reacts with a metal?
A) Hydrogen gas
B) Oxygen gas
C) Carbon dioxide gas
D) Nitrogen gas
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