In Dumas' method of estimation of nitrogen 0.35 g of an organic compound gave 55 mL of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be (Aqueous tension at 300 K = 15 mm) ?

Yogesh Mangal Chemistry 09 Jan, 2018 1 Answer 853 views








A person with unknown blood group under ABO system, has suffered much blood loss in an accident and needs immediate blood transfusion. His one friend who has a valid certificate of his own blood type, offers for blood donation without delay. What would have been the type of blood group of the donor friend?

Nikita Shah Biology 04 Jan, 2018 1 Answer 186 views



A man X has 7 friends, 4 of them are ladies and 3 are men. His wife Y also has 7 friends, 3 of them are ladies and 4 are men. Assume X and Y have no common friends. Then the total number of ways in which X and Y together can throw a party inviting 3 ladies and 3 men, so that 3 friends of each of X and Y are in this party, is?

Devendra Yadav Maths 03 Jan, 2018 2 Answer 402 views









The colour of the X2 molecules of group 17 elements changes gradually from yellow to violet down the
group. This is due to


[A] the physical state of X2 at atom temperature changes from gas to solid down the group


[B] decrease in HOMO-LUMO gap down the group


[C] decrease in  gap down the group


[D] decrease in ionization energy down the group

Rahul Kumar Chemistry 30 Dec, 2017 1 Answer 469 views