What is a homologous series of carbon compounds? List its any two characteristic. Write the name and formula of next higher homologue of HCOOH.

i. Why potato chips manufacturers fill the packet of chips with nitrogen gas?

ii. A student has been collecting silver coins and copper coins. One day she observed a black coating on silver coins and a green coating on copper coins. Which chemical phenomenon is responsible for these coatings? Write the chemical name of black and green coatings.

OR

i. Crystals of copper sulphate are heated in a test for some time.

(a) What is the colour of copper sulphate crystals before heating, and after heating?

(b) What is the source of liquid droplets seen on the inner upper side of the test tube during the heating process?

ii. A metal ‘X’ when dipped in an aqueous solution of aluminium sulphate no reaction is observed whereas when it is dipped in an aqueous solution of ferrous sulphate, the pale green solution turns colourless. Identify metal ‘X’ with reason.

State which of the following chemical reaction will take place, giving a suitable reason for each.

Zn(s)+CuSO₄(aq)→ ZnSO₄(aq) + Cu(s)

Fe(s)+ ZnSO₄(aq) → FeSO₄(aq)+Zn(s)

Zn(s)+ FeSO₄→ ZnSO₄+Fe(s)

Label parts 1 to 6 in the given figure of the brain.

i. Answer the following:

(a) Which hormone is responsible for the changes noticed in females at puberty?

(b) Dwarfism results due to deficiency of which hormone?

(c) Blood sugar level rises due to deficiency of which hormone?

(d) Iodine is necessary for the synthesis of which hormone?

(e) Which hormone controls the metabolism of calcium and phosphorus in human beings?

ii. Give an example of a plant hormone that promotes growth.

Study the given data and answer the questions following the data.

i. What is the term for this type of cross?

ii. What does the data of the column market F₁ indicate?

ii. Express the genotype of the (a) parent (b) F₁ Progeny and (c) F₂ Progeny