21
Which of the following substance will not give carbon dioxide on treatment with dilute acid?
Answer: Lime
Questions
22
Which one of the following can be used as an acid–base indicator by a visually impared student?
Answer: Vanilla essence
23
The pH of the gastric juices released during digestion is
Answer: less than 7
24
To protect tooth decay we are advised to brush our teeth regularly. The nature of the tooth paste commonly used is
Answer: basic
25
One of the constituents of baking powder is sodium hydrogencarbonate, the other constituent is
Answer: tartaric acid
26
What happens to the smell of vanilla or onion in the presence of Acids?
Answer: A small increase in smell
27
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: 16 mL
32
Large crystals of raw salt from the deposits of solid salts are of which colour, in general?
Answer: Brown
35
Why does dry HCl gas not change the colour of the dry litmus paper?
Answer: Because dry HCl gas does not ionize to produce H+ ions
37
What are Olfactory Indicators?
Answer: Substances whose odour changes in acidic or basic media
38
Blue litmus paper turns into which colour in basic conditions?
Answer: No change
39
Which of the following is the milk of magnesia?
Answer: Magnesium hydroxide (Mg(OH)2)
40
When acids are dissolved in water they produce ions which help in conducting the electricity. This process is known as
Answer: Dissociation
