Question

What do you observe when
A Potassium reacts with cold water
i Calcium reacts with cold water
iii) Ammonium dichromate is heated
iv) a crystalline hydrated salt is exposed
to the atmosphere, which is efflorescent
v) A metalic sulphide is made to react
with dilute sulphuric acid
Each part is of 1 marks​

Answer 1

Answer:

A) when potassium reacts with cold water to form a dense fume of hydrogen gas.

1) it causes an exothermic reaction forming bubbles of hydrogen gas.

3)it loses its orande colour and leaves reddish brown gas of nitrogen when heated.

4) the crystalline hydrated salt becomes dehydrated by losing its water to atmosphere. the salt becomes white.

5) the reaction occurs but there are some yellow particles of sulphur in the solution.