Chapter 5 – Acids, Bases and Salts – Fill in the Blanks with Answers (Solved Worksheet)
Question- The _______ taste is a characteristic of acids.
Answer- Sour
Explanation- Acids are known for their sour taste. For instance, the sour taste of citrus fruits like lemons and oranges is due to the presence of citric acid.
Question- Bases usually feel _______ when touched.
Answer- Soapy
Explanation- Bases tend to have a slippery or soapy feel when touched. This is a common characteristic used to identify basic substances.
Question- _______ is present in many fruits and vegetables like amla (Indian gooseberry), citrus fruits, strawberries, and bell peppers.
Answer- Ascorbic Acid (Vitamin C)
Explanation- Ascorbic acid, also known as Vitamin C, is commonly found in a variety of fruits and vegetables. It is an essential vitamin required for various body functions, including the maintenance of skin, blood vessels, bones and cartilage, and wound healing.
Question- Indicators change _______ in the presence of an acid or base.
Answer- Colour
Explanation- Indicators are substances that change colour when they come into contact with an acid or a base, aiding in identifying the nature of a substance.
Question- _______ is a common way to identify acids due to their sour nature.
Answer- Taste
Explanation- Acids are often identified by their sour taste, a distinct characteristic that distinguishes them from bases.
Question- Acetic acid is a key component in _______ used as a preservative and flavouring agent.
Answer- Vinegar
Explanation- Vinegar contains acetic acid which acts as a preservative and also imparts a sour flavour.
Question- Oxalic acid is found in vegetables like _______.
Answer- Spinach
Explanation- Spinach, along with some other vegetables and fruits, contains oxalic acid, a naturally occurring organic acid.
Question- Lactic acid in curd is formed during the _______ of milk.
Answer- Fermentation
Explanation- During the fermentation process, bacteria convert lactose present in milk to lactic acid, which helps in setting the curd.
Question- Sodium hydroxide and potassium hydroxide are used in the manufacture of _______.
Answer- soaps and detergents
Explanation- Both sodium hydroxide and potassium hydroxide are strong bases used in saponification to produce soaps and detergents.
Question- Calcium hydroxide is present in _______.
Answer- lime water
Explanation- Lime water is a dilute solution of calcium hydroxide, used in various applications including water treatment.
Question- Magnesium hydroxide is used to neutralise _______.
Answer- stomach acid
Explanation- Magnesium hydroxide acts as an antacid, helping to neutralise stomach acid and alleviate symptoms of indigestion and heartburn.
Question- Litmus paper turns _______ in the presence of a basic solution.
Answer- blue
Explanation- When exposed to a basic solution, litmus paper turns blue, signifying the basic nature of the solution.
Question- Neutral substances do not change the colour of either red or blue _______ paper.
Answer- litmus
Explanation- Neutral substances maintain the colour of litmus paper, as they do not have acidic or basic properties.
Question- In distilled water, litmus shows a _______ colour.
Answer- mauve (purple)
Explanation- Distilled water is neutral, and thus, when litmus is introduced, it shows a mauve (purple) colour, indicating neutrality.
Question- Turmeric paper is made by applying a paste of turmeric powder and _______ on blotting paper or filter paper.
Answer- water
Explanation- A simple paste made of turmeric powder and water is applied on blotting paper or filter paper to prepare turmeric paper.
Question- Turmeric paper reacts primarily to _______ substances by changing colour.
Answer- basic
Explanation- Turmeric paper is sensitive to basic (alkaline) substances, resulting in a colour change when exposed to them.
Question- In the presence of a neutral substance like sugar, turmeric paper shows _______ change.
Answer- no
Explanation- Since neutral substances like sugar do not have alkaline properties, they do not react with turmeric paper, leaving the colour unchanged.
Question- China Rose indicator is prepared using China rose petals and _______.
Answer- warm water
Explanation- China rose petals are mixed with warm water to extract the colour-changing properties of the petals, creating the China Rose indicator.
Question- When the China Rose indicator is added to acidic solutions, the solution turns _______.
Answer- dark pink or magenta
Explanation- The acidic nature of a solution reacts with the China Rose indicator, resulting in a dark pink or magenta colour change.
Question- Neutral solutions may _______ show significant colour changes when China Rose indicator is added.
Answer- not
Explanation- Neutral solutions, like those of sugar, don’t react significantly with the China Rose indicator, leaving the colour largely unchanged.
Question- In the presence of dilute nitric acid, litmus paper turns _______.
Answer- Red
Explanation- Litmus paper turns red when exposed to acids like dilute nitric acid, indicating the acidic nature of the solution.
Question- When sodium hydroxide is tested, turmeric paper turns _______.
Answer- Red
Explanation- Turmeric paper is sensitive to basic substances like sodium hydroxide, undergoing a colour change to red upon contact.
Question- In the presence of bases, the China Rose solution turns _______.
Answer- Green
Explanation- Bases cause a colour change in the China Rose solution, turning it green, which signifies the presence of a basic substance.
Question- In the presence of phenolphthalein, a neutral solution will have a _______ colour.
Answer- Colourless
Explanation- Phenolphthalein remains colourless in neutral solutions as there are no excess hydrogen or hydroxide ions to trigger a colour change.
Question- During a neutralisation reaction, an acid and a base react to form _______ and a salt.
Answer- Water
Explanation- A neutralisation reaction between an acid and a base typically yields water and a salt as the products.
Question- In an acidic solution, phenolphthalein appears _______.
Answer- Colourless
Explanation- In acidic solutions, phenolphthalein remains colourless because the environment does not facilitate the structural change needed for the compound to absorb and emit colour.
Question- During neutralisation, the acid and base react to form _____ and _____.
Answer- Salt, Water
Explanation- A typical neutralisation reaction involves the reaction of an acid and a base to form salt and water as products.
Question- The container feels _____ due to the evolution of heat during neutralisation.
Answer- Warm
Explanation- The release of heat during a neutralisation reaction causes the container to feel warm, as it is an exothermic process.
Question- In a neutralisation reaction, the nature of the resulting salt can be _______, _______, or neutral.
Answer- Acidic, Basic
Explanation- The salt produced in a neutralisation reaction can exhibit acidic, basic, or neutral characteristics based on the participating reactants.
Question- In cases of indigestion, the consumption of antacids helps in the formation of water and _______.
Answer- Magnesium chloride
Explanation- Antacids often contain magnesium, which reacts with stomach acid to produce magnesium chloride and water, aiding in neutralising stomach acidity.
Question- To neutralise an ant bite, a basic solution like _______ or calamine can be applied.
Answer- Baking soda
Explanation- Baking soda is a common remedy that, due to its basic nature, helps in neutralising the acidic effect of an ant bite.
Question- In managing factory wastes, basic substances are added to acidic wastes to neutralise them, protecting _______ life.
Answer- Aquatic
Explanation- Neutralising acidic factory wastes with basic substances before disposal helps in preserving aquatic life by preventing water pollution and maintaining a balanced pH in water bodies.
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