Question

Pls Help ..I am having exam tomorrow Q19​

Answer 1

Hi, here is your answer

a) X= magnesium since atomic no. is given to be 12

Y=Oxygen Since, 1/40 mole =1 g

therefore 1 g =40 g

compound mass becomes 40 g

mass of mg= 24............ 40-24=mass of y

=> 16g=Y (oxygen)

b) E.C of mg=2,8,2.........=> valency=2

Similarly valency of oxygen=2

c)40 g of compound=6.022*10²³ molecules

=>1 g of compound=6.022*10²³/40

d)No. of protons in X (magnesium)=12 (no. of protons= atomic no.)

No. of neutrons in X (magnesium)=Mass no. -No.of protons

=>24-12

=>12

Similarly it can be calculated for Oxygen

now add the both no.of protons to get no.of protons in the compound and repeat the same with atomic numbers.

Hope this answer is helpful and all the best for exam