A solution turns red litmus blue; its pH is likely to be?

1

(a)

1

(b)

4

(c)

5

(d)

10

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 of HCl solution required to neutralise it will be 

1

(a)

4 ml

(b)

8 ml

(c)

12 ml

(d)

16 ml

Sodium carbonate is a basic salt because it is a salt of

1

(a)

Strong acid and strong base

(b)

weak acid and weak base

(c)

strong acid and weak base

(d)

weak acid and strong base

If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?

1

(a)

Wash the hand with saline solution

(b)

Wash the hand immediately with plenty of water and apply a paste od sodium hydrogen carbonate

(c)

After washing with plenty of water apply solution of solution hydroxide on the hand

(d)

Neutralise the acid with a strong alkali

The pH of the gastric juices released during digestion is

1

(a)

less than 7

(b)

more than 7

(c)

equal to 7

(d)

equal to 0

Which one of the following can be used as an acid-base indicator by a visually impaired student?

1

(a)

Litmus

(b)

Turmeric

(c)

Vanilla essence

(d)

Petunia leaves

Which among the following is not a base?

1

(a)

NaOH

(b)

KOH

(c)

\(NH_4OH\)

(d)

\(CH_2H_5OH\)

Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper.  What would be the colour obtained?

1

(a)

Red

(b)

Yellow

(c)

Yellowish green

(d)

Blue

Which of the following is (are) true when HCl (g) is passed through water?

(i) It does not ionise in the solution as it is a covalent compound.

(ii) It ionises in the solution

(iii) It gives both hydrogen and hydroxyl ion in the solution

(iv) It forms hydronium ion in the solution due to the combination of hydrogen ion with water molecule

1

(a)

(i) only

(b)

(iii) only

(c)

(ii) and (iv)

(d)

(iii) and (iv)

Which of the following statement is true for acids?

1

(a)

Bitter and change red litmus to blue

(b)

Sour and change red litmus to blue

(c)

Sour and change blue litmus to red

(d)

Bitter and change blue litmus to red

The pH value of three solutions A, B, and C having equal molar concentration are respectively 2.0, 7.0, and 13.0 at 298 K.  Which of the three solutions represents an acid solution?

1

(a)

A represents an acid solution.  This is because the pH value of A is 2.0 and the pH value of an acids lies between 1 and 6.

(a) Give Arrhenius definition of an acid and a base.
(b) Choose strong acid and strong base from the following:
 \(CH_3COOH,\ NH_4OH,\ KOH,\ HCl\)

1

(a)

(a) According to Arrhenius theory, acids are substances that produce \(H^+\) ions when mixed with water.  On the other hand, based are substances that produce \(OH^-\) ions when mixed with water.
(b) \(NH_4OH\) is a weak base and HCl is a strong acid.

Dry ammonia gas has no action on litmus paper, but a solution of a ammonia in water turns red litmus paper blue, why is it so?

1

(a)

A solution of ammonia in water results in the formation of ammonium hydroxide \((NH_4OH).\)  Ammonium hydroxide is basic in nature and turns red litmus blue.

Name the acid present in ant sting.

1

(a)

Formic acid(Methanoic acid) HCOOH.

Which gas is usually liberated when an acid reacts with a metal?

1

(a)

Hydrogen gas.

Which is a stronger acid, with pH = 5 or with pH = 2 ?

1

(a)

pH = 2 (lower the pH, stronger the acid).

What is the effect of an increase in the concentration of H⁺ ions? 1M HCl or 1M CH₃COOH.

1

(a)

1 M HCl has a higher concentration of H⁺  ions because when HCl dissolves in water it dissociates completely into ions while CH₃COOH is a weak acid and does not dissociate into ions completely.