Class 10 Chemistry
Acid Base and Salt
NCERT Exercise Solution - Part I
Write word equations and then balanced equations for the reaction taking place when
- Dilute sulphuric acid reacts with zinc granules.
Answer: Sulphuric acid + Zinc → Zinc sulphate + Hydrogen
Zn + H2SO4 ⇨ ZnSO4 + H2
- Dilute hydrochloric acid reacts with magnesium ribbon.
Answer: Hydrochloric acid + Magnesium → Magnesium chloride + Hydrogen
Mg + 2HCl ⇨ MgCl2 + H2
- Dilute sulphuric acid reacts with aluminium powder.
Answer: Suphuric acid + Aluminium → Aluminium sulphate + Hydrogen
2Al + 3H2SO4 ⇨ Al2(SO4 )3 + 3H2
- Dilute hydrochloric acid reacts with iron filings.
Answer: Sulphuric acid + Iron → Ferric chloride + Hydrogen
2Fe + 6HCl ⇨ 2FeCl3 + 3H2
A solution turns red litmus blue, its pH is likely to be
Answer: (d) 10
A solution reacts with crushed egg-shells to give a gas that turns lime-water milky. The solution contains
Answer: (b) HCl
10 mL of a solution of NaOH is found to be completely neutralised by 8 mL of a given solution of HCl. If we take 20 mL of the same solution of NaOH, the amount HCl solution (the same solution as before) required to neutralise it will be
Answer: (d) 16 mL
Which one of the following types of medicines is used for treating indigestion?
Answer: (c) Antacid
Compounds such as alcohols and glucose also contain hydrogen but are not categorised as acids. Describe an Activity to prove it.
Answer: Following activity can be done for this:
- Take solutions of glucose, alcohol, hydrochloric acid, sulphuric acid, etc.
- Fix two nails on a cork, and place the cork in a 100 mL beaker.
- Connect the nails to the two terminals of a 6 volt battery through a bulb and a switch, as shown in figure.
- Now pour some glucose solution in the beaker and switch on the current.
- Repeat with alcohol solution and hydrochloric acid.
It is observed that bulb does not glow using glucose or alcohol solution. While if a solution of acid is used instead of glucose or alcohol solution, bulb glows.
Bulb glows when the solution of hydrochloric acid is used, because it dissociates hydronium ion in aqueous solution. But glucose and alcohol do not dissociate hydronium ion in the water, which is responsible for the conduction of electricity. Hence solution of glucose and alcohol do not conduct electricity.