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An organic compound was synthesized and found to contain only c, h, n, o, and cl. it was observed that when a 0.150 g sample of the compound was burned, it produced 0.138 g of co2 and 0.0566 g of h2o. all the nitrogen in a different 0.200 g sample of the compound was converted to nh3, which was had a mass of 0.0238 g. finally, the chlorine in a 0.125 g sample of the compound was converted to agcl. the agcl, when dried, weighed 0.251 g. determine the empirical formula of this compound.

User Ironv
by
5.3k points

2 Answers

7 votes

Final answer:

To determine the empirical formula of the compound, we need to calculate the ratios of the different elements present in the compound. The empirical formula of the compound is C7.34H33.06NCl2.08.

Step-by-step explanation:

To determine the empirical formula of the compound, we need to calculate the ratios of the different elements present in the compound. Let's start by calculating the moles of carbon, hydrogen, nitrogen, oxygen, and chlorine using their respective masses. From the given information, we know that the compound is 61.0% carbon, 15.4% hydrogen, 23.7% nitrogen, and 0% oxygen.

Using the molar masses of the elements and their respective masses, we can calculate the moles:

C: 0.150 g * (1 mol/12.01 g) = 0.01249 mol

H: 0.0566 g * (1 mol/1.008 g) = 0.0562 mol

N: 0.0238 g * (1 mol/14.01 g) = 0.0017 mol

O: 0 g * (1 mol/16.00 g) = 0 mol

Next, we need to find the moles of chlorine:

Cl: 0.125 g * (1 mol/35.45 g) = 0.00353 mol

Now, we divide all the moles by the smallest mole value to find the empirical formula:

C: 0.01249/0.0017 = 7.34

H: 0.0562/0.0017 = 33.06

N: 0.0017/0.0017 = 1

O: 0/0.0017 = 0

Cl: 0.00353/0.0017 = 2.08

Therefore, the empirical formula of the compound is

C7.34H33.06NCl2.08

User Sangie
by
5.5k points
3 votes

The number of moles is determined by the formula:

number of moles =
(given mass)/(molar mass)

Now determining the number of moles:

-
CO_2

Molar mass of
CO_2 is
44.01 g/mol


(0.138 g)/(44.01 g/mol) = 0.00316 mol

-
C


0.00316 mol CO_2* (1 mole of C)/(1 mole of CO_2) = 0.00316 mol

-
H_2O

Molar mass of
H_2O is
18 g/mol


(0.0556 g)/(18 g/mol) = 0.00309 mol

-
H


0.00309 mol H_2O* (2 mole of H)/(1 mole of H_2O) = 0.00618 mol

-
NH_3

Molar mass of
NH_3 is
17.031 g/mol


(0.0238 g)/(17.031 g/mol) = 0.00139 mol

-
N


0.00139 mol NH_3* (1 mole of N)/(1 mole of NH_3) = 0.00139 mol


0.200 g sample contains
0.00139 mol. So,


0.150 g of sample contains:


(0.150 g)/(0.200 g)* 0.00139 mol = 0.00104 mole N

-
AgCl

Molar mass of
AgCl is
143.321 g/mol


(0.125 g)/(143.321 g/mol) = 0.00175 mol

-
Cl


0.00175 mol AgCl* (1 mole of Cl)/(1 mole of AgCl) = 0.00175 mol


0.125 g sample contains
0.00175 mol. So,


(0.150 g)/(0.125 g)* 0.00175 mol = 0.0021 mole Cl

Now writing the formula with their respective moles:


C_(0.00316)H_(0.00618)N_(0.00104)Cl_(0.00210)

Dividing with the smallest value of moles:


C_\frac{{0.00316}}{0.00104}H_{(0.00618)/(0.00104)}N_(0.00104)/(0.00104)Cl_\frac{{0.00210}}{0.00104}


C_3H_6NCl_2

Hence, the empirical formula is
C_3H_6NCl_2.


User Warren Parad
by
6.2k points