##### A compound is composed of only C and I It contains 5.935 C by mass and has a

label Chemistry
account_circle Unassigned
schedule 1 Day
account_balance_wallet \$5

A compound is composed of only C and I.  It contains 5.935 % C by mass and has a molar mass of 809.44 g/mol. What is its molecular formula?

Need help, step by step...i need to understand this!

Oct 9th, 2015

element                   C                                                    I

Moles                     5,935/ 12                                    94.065/126.9

=                               0.4946                                       0.74125

mole ratio     0.4946/0.4946               :                     0.74125/0.4946

1                                        :            1.5

(C1 I 1.5)n = 809.44

12n + 190.35n = 809.44

202.35 n = 809.44

n = 809.44/202.35

n= 4

formula will be

(C1 I 1.5)4

= C4 I 6

MOLECULAR FORMULA IS THUS  C4 I 6

Oct 9th, 2015

what does n mean?

where did 190.35 come from?

where did 202.35 come from?

Oct 9th, 2015

Once we get the mole ration we get  what we call the emprical formula which will be

C1 I 1.5

now to get the molecular formula we we get a constant n which when multuplid by the molar masses of atoms in empirical formula will give us the molecular weight

(C1 I 1.5)n = 809.44

molar mass of C = 12

MOLAR mass of I = 126.9

thus replacing in above equation we get

(12)n + 12.96*1.5*n = 809.44

12n + 190.35n = 809.44

n = 809.44/202.35

n= 4

once we get n we multiply the emprical formula by n to get molecular formula

C I1.5) 4

= C4 I6

Oct 9th, 2015

...
Oct 9th, 2015
...
Oct 9th, 2015
Sep 23rd, 2017
check_circle