- 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) Base
B) Acidic
C) Alkaline
D) Neutral
- 2. What is the pH of a neutral solution?
A) 7
B) 14
C) 1
D) 4
- 3. Which of the following is a common base?
A) Sulfuric acid
B) Sodium hydroxide
C) Citric acid
D) Carbonic acid
- 4. Which acid is found in lemons?
A) Citric acid
B) Sulfuric acid
C) Nitric acid
D) Acetic 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) Hydrochloric acid
B) Sulfuric acid
C) Acetic acid
D) Nitric acid
- 7. The pH scale ranges from:
A) 5 to 15
B) 1 to 10
C) 0 to 14
D) 0 to 12
- 8. A solution with a pH of 2 is classified as:
A) Neutral
B) Acidic
C) Alkaline
D) Basic
- 9. Baking soda is a common name for:
A) Sulfuric acid
B) Citric acid
C) Sodium bicarbonate
D) Phosphoric acid
- 10. Which acid is commonly found in batteries?
A) Sulfuric acid
B) Nitric acid
C) Hydrochloric acid
D) Acetic acid
- 11. What color does blue litmus paper turn when in contact with an acid?
A) Green
B) Blue
C) Yellow
D) Red
- 12. A substance with a pH of 7 is classified as:
A) Neutral
B) Acidic
C) Basic
D) Alkaline
- 13. Which of the following is an example of a weak base?
A) Ammonia
B) Calcium hydroxide
C) Potassium hydroxide
D) Sodium hydroxide
- 14. What is the product of a reaction between an acid and a base?
A) Hydrogen gas
B) Salt and water
C) Oxygen gas
D) Carbon dioxide
- 15. Which acid is naturally found in milk?
A) Hydrochloric acid
B) Lactic acid
C) Acetic acid
D) Sulfuric acid
- 16. What happens when an acid reacts with a base?
A) Sublimation
B) Combustion
C) Oxidation
D) Neutralization
- 17. Acids donate ________ in a chemical reaction.
A) Neutrons
B) Photons
C) Protons
D) Electrons
- 18. What is the chemical formula of hydrochloric acid?
A) H2O
B) CO2
C) HCl
D) NaOH
- 19. What is the role of a buffer solution?
A) Acts as a catalyst
B) Decreases pH
C) Resists changes in pH
D) Increases pH
- 20. A solution with a pH of 9 is classified as:
A) Acidic
B) Neutral
C) Basic
D) Alkaline
- 21. What substance is produced when an acid reacts with a metal?
A) Hydrogen gas
B) Nitrogen gas
C) Carbon dioxide gas
D) Oxygen gas
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