8 Most VSAQ’s of Acids, Bases and Salts Chapter in Class 10th Physical Science (TS/AP)

2 Marks

VSAQ-1 : Write the required material in the experiment ‘acids react with metals’?

Materials Required for the Experiment ‘Acids React with Metals’

  1. Test Tube: To hold the reaction mixture.
  2. Delivery Tube: For transferring gases produced during the reaction.
  3. Glass Tube: Used in the setup for observing gas release.
  4. Candle: To test the gas produced in the reaction.
  5. Soap: For creating a soap solution to trap the gas.
  6. Water: Essential for preparing dilute hydrochloric acid and the soap solution.
  7. Dilute Hydrochloric Acid (HCl): The acid used to react with the metal.
  8. Zinc Granules: The metal that reacts with the hydrochloric acid.
  9. Cork: To seal the test tube and direct the gas through the delivery tube.

VSAQ-2 : Observe the table and answer the following questions.

S.No.Name of the substancespH value
1.Distilled water7
3.Sodium hydroxide13.7

i.Vinegar is added to distilled water. If methyl orange indicator is added to this solution, what will be the colour of the solution?

ii.According to the given pH values, what is the nature of the substances.

Observation of pH Changes and Indicator Responses

1. Vinegar Added to Distilled Water with Methyl Orange Indicator

  • Initial Solution: When vinegar (contains acetic acid, a weak acid) is added to distilled water, the pH becomes slightly less than 7.
  • Indicator Reaction: Adding methyl orange indicator to this solution will turn it yellow, indicating acidity.

2. Nature of Substances Based on pH Values

  • Distilled Water: Has a pH of 7, which is neutral.
  • Vinegar: Being a weak acid, it has a pH slightly less than 7, making it acidic.
  • Sodium Hydroxide: With a pH greater than 7, it is classified as a strong base.

VSAQ-3 : What is a neutralization reaction?

Understanding a Neutralization Reaction

  1. A neutralization reaction occurs when an acid and a base react to produce salt and water.
  2. The general equation for a neutralization reaction is:
    Acid + Base → Salt + Water

VSAQ-4 : How will you test for the gas which is liberated when hydrochloric acid reacts with a metal?

Testing for Hydrogen Gas in the Reaction of Hydrochloric Acid with a Metal

  1. To test for hydrogen gas released in the reaction of hydrochloric acid with a metal, bring a burning candle near the gas.
  2. If it’s hydrogen, it will make a “pop” sound when ignited.

VSAQ-5 : Mention the precautions to take while conducting an experiment to prove acids produce ions only in aqueous solutions.

Precautions for Conducting Acid Experiments

  1. Wear Protective Gear:
    Always wear protective gear, including gloves and goggles, to protect against spills and splashes.
  2. Use a Test Tube Holder:
    Utilize a test tube holder to safely handle test tubes and avoid burns.
  3. Ensure Good Ventilation:
    Conduct experiments in a well-ventilated area to prevent inhalation of harmful fumes.
  4. Label Chemical Containers:
    Accurately label all chemical containers to avoid confusion and mishandling.
  5. Know Emergency Equipment Locations:
    Be aware of the location of emergency equipment, such as eyewash stations and fire extinguishers.
  6. Follow Experiment Procedures:
    Strictly follow the procedures outlined for the experiment to ensure safety.

VSAQ-6 : How many molecules of water of crystallization are there in copper sulphate and washing soda crystals?

Molecules of Water of Crystallization in Copper Sulphate and Washing Soda Crystals

  1. Copper Sulphate Crystals: Contain 5 molecules of water of crystallization
    $$[CuSO_4 \cdot 5H_2O]$$
  2. Washing Soda Crystals: Contain 10 molecules of water of crystallization
    $$[Na_2CO_3 \cdot 10H_2O]$$

VSAQ-7 : Define universal indicator.

Definition of Universal Indicator

A universal indicator is a mixture of several indicators that displays a range of colors across the pH scale. It is used to indicate the acidity or alkalinity of a solution.

VSAQ-8 : A few drops of sulphuric acid is added to water before electrolysis, why?

Reason for Adding Sulfuric Acid to Water Before Electrolysis

  1. Sulfuric acid (H2SO4) is added to water before electrolysis because water is a poor conductor of electricity on its own.
  2. By adding sulfuric acid, it ionizes in water, releasing H+ ions and SO4²- ions.
  3. These ions enhance the conductivity of the solution, allowing for efficient electrolysis.