1. If a blue litmus paper when dipped in a solution, remains blue, it implies the solution is either basic or neutral. https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

    If a blue litmus paper when dipped in a solution, remains blue, it implies the solution is either basic or neutral.

    https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

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  2. Turmeric is yellow in colour. When a base is added to it, the solution turns into pink colour. However turmeric remains yellow when an acid or neutral solution is added to it. We shall perform the following steps to identify the solution is base, acid or neutral. • Take few drops from each solutionRead more

    Turmeric is yellow in colour. When a base is added to it, the solution turns into pink colour. However turmeric remains yellow when an acid or neutral solution is added to it. We shall perform the following steps to identify the solution is base, acid or neutral.
    • Take few drops from each solution and test it with turmeric solution. If the solution turns into pink colour that solution is base i.e. Sodium Hydroxide. Mark that beaker (containing solution) as base.
    • Take a test tube and add few drops of base solution and second solution. Check if test tube becomes warm and then add turmeric solution to it. If the colour does not change, it means the solution added is acidic (HCl). The test tube becomes warm due to neutralization.
    • If the test tube of the above solution does not warm and it does show pink colour when turmeric is added, the second solution is neutral.

    https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

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  3. The wastes of many factories contain acids. If they are allowed to flow into the water bodies, the acids will kill aquatic organisms. The factory wastes are, therefore, neutralized by adding basic substances. https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

    The wastes of many factories contain acids. If they are allowed to flow into the water bodies, the acids will kill aquatic organisms. The factory wastes are, therefore, neutralized by adding basic substances.

    https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

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  4. The sting of an ant contains formic acid which causes irritation on the skin. Calamine solution contains, zinc carbonate which is a base. Calamine solution neutralizes the acid effect of the ant bite when applied on the skin. https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

    The sting of an ant contains formic acid which causes irritation on the skin. Calamine solution contains, zinc carbonate which is a base. Calamine solution neutralizes the acid effect of the ant bite when applied on the skin.

    https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

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  5. Due to release of excess of hydrochloric acid, we suffer from acidity. An antacid tablet consists of a base like Milk of Magnesia (magnesium hydroxide). It neutralizes the effect of excessive acid and brings relief. https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

    Due to release of excess of hydrochloric acid, we suffer from acidity. An antacid tablet consists of a base like Milk of Magnesia (magnesium hydroxide). It neutralizes the effect of excessive acid and brings relief.

    https://www.tiwariacademy.com/ncert-solutions/class-7/science/chapter-5/

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