Page 33 - NCERT Science Class 10 English Medium

Do You Know? Nettle is a herbaceous plant which grows in the wild. Its leaves have stinging hair,
Nature provides neutralisation options

which cause painful stings when touched accidentally. This is due to the methanoic
acid secreted by them. A traditional remedy is rubbing the
area with the leaf of the dock plant, which often grows beside
the nettle in the wild. Can you guess the nature of the dock
plant? So next time you know what to look out for if you
accidentally touch a nettle plant while trekking. Are you aware
of any other effective traditional remedies for such stings?

Table 2.3 Some naturally occurring acids

Natural source Acid Natural source Acid

Vinegar Acetic acid Sour milk (Curd) Lactic acid
Orange Citric acid Lemon Citric acid
Tamarind Tartaric acid Ant sting Methanoic acid
Tomato Oxalic acid Nettle sting Methanoic acid

Q U E S T I O N S

1. You have two solutions, A and B. The pH of solution A is 6 and pH of
solution B is 8. Which solution has more hydrogen ion concentration?
Which of this is acidic and which one is basic?
+
2. What effect does the concentration of H (aq) ions have on the nature of the
solution? ?
+
3. Do basic solutions also have H (aq) ions? If yes, then why are these basic?
4. Under what soil condition do you think a farmer would treat the soil of his
fields with quick lime (calcium oxide) or slaked lime (calcium hydroxide) or
chalk (calcium carbonate)?

2.4
2.4 MORE ABOUT SALMORE ABOUT SALTSTS
ABOUT
SAL
MORE ABOUT SALTS
2.4 MORE
2.4 MORE ABOUT SALTSTS
2.4
In the previous sections we have seen the formation of salts during
various reactions. Let us understand more about their preparation,
properties and uses.
2.4.1 Family of Salts
Activity 2.132.13
Activity 2.13
Activity
Activity 2.13
Activity 2.13
n Write the chemical formulae of the salts given below.
Potassium sulphate, sodium sulphate, calcium sulphate,
magnesium sulphate, copper sulphate, sodium chloride, sodium
nitrate, sodium carbonate and ammonium chloride.

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