QI. Give one word for each of the following :
1) The acidic liquid injected into our body on ant sting .
2) A new substance formed on neutralization .
3) The acid present in lemon juice.
4) The rain containing excess of acids .
5) The most commonly used natural indicators.
Ans:
1) Formic acid 2) Salt 3) Citric 4) Acid rain 5) Litmus .
QII. Give two examples for each of the following:
1. Neutral solution
Ans: Sugar solution, common salt solution .
2. Gaseous pollutants responsible for acid rain.
Ans: Carbon dioxide (CO2), Sulphur dioxide (SO2) .
3. Natural Indicators .
Ans: Litmus, Turmeric .
4. Natural substances which are acidic .
Ans: Lemon, Orange .
Q.III Match the items in Column I with Column II :
Column I Column II
1. Formic acid a) Vinegar
2. Lactic acid b) Salt
3. Hydrochloric acid c) Antacid
4. Sodium chloride d) Antacid
5. Acetic acid e) Curd
6. Milk of magnesia f) Indigestion in stomach
Ans:
1) c 2) e 3) f 4) b 5) a 6) d .
Q.IV Answer the following questions :
1. Why does a turmeric stain on white shirt is turn red when it is washed with soap?
Ans: Turmeric stain turns red because soap solution is basic in nature.
2. Name two basic substances that we use in our everyday life.
Ans: The two basic substances are soap/detergent and baking soda .
3. State the effect of acid rain.
Ans: Acid rain can cause damage to buildings, historical movements, plants and animals.
4. Why should we take care while handling laboratory acids and bases.
Ans: We should take care while handling laboratory acids and bases because they are corrosive in nature, irritating and harmful to the skin.
5. State the colour change when phenolphthalein is an a) acid b) base .
Ans:
a) solution remains colourless .
b) solution turns to pink colour .