The mole (unit)?

Question

how many molecules in 7g of N2?

how many nitrogen atoms are there in this substance?

Answer 1

Molar mass N2 = 28g

28 g contains 6.02*1023 molecules.

7g N2 contains 1/4 of this number. (28/7)

Answer: 1.505*10^23 molecules in 7g N2

1 molecule of N2 contains 2 atoms N. Therefore 7g N2 contains 1.505*2 = 3.01*10^23 atoms.

Answer 2

As 1 dozon = 12 in number  

         1 mole=6.023x10^23

molecular weight of any substance contains 1 mole which is this number of it.

thus, 28 is mol.wt. of N2 and it contains

                                                        6.023x10^23 N2 molecules

then 7g of it =1.505x10^23 molecules

As each molecule of N2 is having two atoms, these many molecules will have double the number of atoms

i.e. 2x 1.505x10^23= 3.012x10^23.

Answer 3

in order to find the mole , you divide 7 by 14 ( N2= 14)

1 mole contain 6.023x10^23 atoms , so we will have 6.023 x 10^23 x 7 / 14  atoms

Answer 4

14 x 2 g(because 2 atoms are there in one molecule of Nitrogen).=6.022 x 10^23

28g=6.022 x 10^23

1g=(6.022 x 10^23)/28

7g=(6.022 x 10^23)/28  x  7=(6.022 x 10^23)=1.505 x 10^23 molecules

As there are 2 atoms in 1 molecule of N

1.505 x 10^23 molecules has atoms=2x 1.505x10^23= 3.012x10^23.

Answer 5

molecular weight of N2 is 28 and there are 6.02x10^23 molecules in 28g of nitrogen.

in 7 g there will be 6.02x10^23/4 molecules.

in 28g of nitrogen there are 2x6.02x10^23 atoms so there will be 2x6.02x10^23/4 atoms in 7g

Answer 6

i think it's 1.505 x 10^23 molecules of N2..

do u mean Nitrogen as in N. or nitrogen gas, which is N2..

if it's nitrogen gas.. there's 2 atoms..

if it's nitrogen (N) then there's 1 atom..

i havent done chemistry since months ago..