2125 Match the description to the amounts AE Description 21

21-25 Match the description to the amounts A-E Description 21. Which sample has the least mass? 22. Which sample has the greatest mass? 23. Which sample has the least atoms? 24. Which sample has the most atoms? Samples A) 1 mole of Ne B) 2 moles of Ar C) ¼ mole of Br2 D) 1/4 mole of Hg E) 4 mole of He 25, Which sample has the greatest volume at STP? 26-30. Match the following descriptions to the amounts given as A-E

Solution

Masses :)

A) 1*20 = 20gm = 1*Avagadro number(N)=6.023*10^23atoms

B) 2*40=80 gm=2*N atoms

C)1/4 *2*80 = 40gm =1/4*Natoms

D)1/4 *200 = 50 gm= 1/4*N

E)4*4 = 16 gm=4*N atoms

21)E

22)B

23)C,D

24)E

25)Eone mole of any gas occupies 22.4 litre volume at stp

Therefore 4 moles of He occupies 4*22.4 litres of volume