Question

metal (M) reacts vigorously with water to form a solution (S) and a gas (G). The solution S turns red

litmus to blue whereas gas G is very light gas and burns with a pop sound. Metal M has a low melting point and

is used as a coolant in nuclear reactors.

Now choose the correct options:

19(i) Identify the metal M?

a) Calcium b) Potassium c) Sodium d) Magnesium
19(ii) Which of the following statements is true about metal M?

I) It can be cut with a knife III) It is present in first group of periodic table

II) It is an inert element IV) Its valency is +2

a) I and II b) I and III c) I, II and III d) Only IV

19(iii) The gas G is:

a) Colourless and odourless b) Used as rocket fuel c) Is an inert gas d) Both a and b

19(iv) If we add phenolphthalein in S, what will happen?

a) The solution turns pink c) The solution remains colourless

b) The solution turns blue d) the solution becomes green​

Answer 1

Answer:

19  .(i)  (c)Sodium

      (ii) (a) I and II

     (iii) (d) Both a and b

     (iv) (a)The Solution turns pink