The Analytical Chemistry chapter in Sindh Board Class 10 Chemistry introduces the methods and principles used to analyze substances and determine their composition. It explains qualitative and quantitative analysis, laboratory techniques, and the use of indicators in titrations. Students learn about gravimetric and volumetric analysis, the preparation and standardization of solutions, and the role of analytical chemistry in industries such as pharmaceuticals, food, and environmental testing.
1. What is the main focus of analytical chemistry?
- A. Studying the rates of chemical reactions
- B. Designing industrial plants
- C. Determining the composition of substances ✅
- D. Producing new synthetic materials
Explanation: Analytical chemistry focuses on identifying and quantifying the chemical components of materials.
2. Which branch of analytical chemistry identifies the components of a substance?
- A. Qualitative analysis ✅
- B. Quantitative analysis
- C. Physical chemistry
- D. Industrial chemistry
Explanation: Qualitative analysis determines the types of substances present without measuring their quantities.
3. Which branch of analytical chemistry measures the amount of a substance present?
- A. Qualitative analysis
- B. Quantitative analysis ✅
- C. Organic chemistry
- D. Biochemistry
Explanation: Quantitative analysis determines how much of a particular substance is present.
4. Which of the following is a volumetric analysis technique?
- A. Filtration
- B. Titration ✅
- C. Evaporation
- D. Distillation
Explanation: Volumetric analysis involves measuring the volume of a reactant needed to complete a reaction, as in titrations.
5. What is an indicator in titration?
- A. A reactant
- B. A substance that changes color at the endpoint ✅
- C. A solvent
- D. A product
Explanation: An indicator signals the completion of a reaction by changing color.
6. Which indicator is commonly used for strong acid–strong base titrations?
- A. Methyl orange
- B. Phenolphthalein ✅
- C. Litmus
- D. Universal indicator
Explanation: Phenolphthalein is often used because it changes color sharply in the pH range of 8.3 to 10.
7. What is the endpoint in titration?
- A. The point where the indicator changes color ✅
- B. The point where the reaction starts
- C. The point where all reactants are added
- D. The point where heating stops
Explanation: The endpoint is the stage in a titration when the indicator shows that the reaction is complete.
8. Which apparatus is used to deliver a measured volume of solution in titration?
- A. Pipette
- B. Burette ✅
- C. Beaker
- D. Conical flask
Explanation: A burette allows precise measurement of liquid volumes during titration.
9. What is standardization of a solution?
- A. Determining its exact concentration ✅
- B. Mixing it with another solution
- C. Evaporating the solvent
- D. Filtering impurities
Explanation: Standardization involves finding the exact concentration of a prepared solution using a primary standard.
10. Which of these is a primary standard substance?
- A. Hydrochloric acid
- B. Sodium carbonate ✅
- C. Sulfuric acid
- D. Ammonia solution
Explanation: Primary standards are stable, pure substances like sodium carbonate that can be used to prepare standard solutions.
11. Gravimetric analysis is based on:
- A. Measuring the mass of a substance ✅
- B. Measuring the volume of a gas
- C. Measuring light absorption
- D. Measuring temperature change
Explanation: Gravimetric analysis involves determining the quantity of an analyte by measuring mass.
12. Which safety measure is essential in analytical chemistry labs?
- A. Wearing gloves and goggles
- B. Using fume hoods
- C. Labeling all chemicals
- D. All of the above ✅
Explanation: Personal protective equipment, proper ventilation, and correct labeling are all important safety measures.