Question

Fill in the blanks
1) A cannon after firing recoils due to _______________
2) Magnesium ribbon on burning produces an ash. The colour of the ash is ____________
3) What happens when a solution of sodium sulphate is added to barium chloride___________
4) Akash observed an onion peel under the microscope. The peel was stained and it appeared pink in colour. The stain used is_____________________

Answer 1

1) A cannon after firing recoils due to Force exerted by cannon ball on the cannon.
    A cannon after firing recoils due to Conservation of linear momentum. 
    A cannon after firing recoils due to Newton's third Law of motion.

2) Magnesium ribbon on burning produces an ash. The color of the ash is bright white.
    The powder is Magnesium Oxide (Mg O).

3) Na₂ SO₄ (aqua) + Ba Cl₂ (aqua) -> 2 Na Cl (solid) + Ba SO₄ (solid)
    In solution sodium and sulfate exist as ions. Barium and chloride also dissociate into ions.  Insoluble Barium Sulfate precipitate is formed.  These are white crystals.
   
4) The stain used is perhaps iodine. I am not sure whether iodine results in purple stain or pink.

Answer 2

Due to Newton's third law of motion.
2.Magnesium ribbon on burning produces an ash. The colour of the ash is White.
3.When the solution of sodium sulphate is added to barium chloride we see displacement reaction.And it becomes sodium chloride and barium sulphate.
4. Dont know but i can guess Alcohol.