An organic compound containing 78.5% carbon, 13.1% nitrogen, 8.4% hydrogen. If the molar mass of the compound is 107 g/mol, what is the empirical and molecular formulas?

Md Ariful Islam

0 like 0 dislike
1 views
Share with your friends

1 Answers

Md Ariful Islam

Call

With all these problems, we assume a mass of $100*g$ and divide the individual elemental masses thru by the , i.e.

$C:$ $(78.5*g)/(12.011*g*mol^-1)=6.54*mol.$

$H:$ $(8.4*g)/(1.00794*g*mol^-1)=8.33*mol.$

$N:$ $(13.1*g)/(14.01*g*mol^-1)=0.935*mol.$

We divide thru by the smallest molar quantity, that of nitrogen, to get an empirical formula of $C_7H_9N$. The hydrogen ratio took a bit of rounding up.

Now the $"molecular formula"$ is always a multiple of the $"empirical formula"$. So we solve for $n$ in the equation $nxx(7xx12.011+9xx1.00794+1xx14.01)*g*mol^-1=107*g*mol^-1.$

Clearly, $n=1$, and the $"molecular formula"$ $-=$ $C_7H_9N$.

0 like 0 dislike
1 views
Talk Doctor Online in Bissoy App
An unknown compound has a percent composition of 52.10% potassium, 15.8% carbon, and 32.1% oxygen. The molar mass of the compound is 150.22 g/mol. What is the empirical formula and the molecular formula of this compound?

As is typical with these questions, we assume $100*g$ of unknown compound, and work out the MOLAR quantities of each element present: $" moles of C":$ $(15.8*g)/(12.011*g*mol^-1)=1.32*mol$ $" moles of...

1 Answers 1 views
A compound containing only carbon and hydrogen has a carbon-to-hydrogen mass ratio of 11.89. Which carbon-to-hydrogen mass ratio is possible for another compound composed only of carbon and hydrogen?

Trying to present a possible Answer We know that the molar mass of carbon and hydrogen are $C=12"g/mol" and H = 1"g/mol"$ When Carbon Hydrogen mass ratio is 11.89 The...

1 Answers 1 views
The given percent composition of an organic compound is $48.76% "C"$ and $8.04% "H"$. Its molecular mass is $"74 g/mol"$. What are its empirical and chemical formulas?

Refer to the comments. The given percent composition of an organic compound is $48.76% "C"$ and $8.04% "H"$. The remaining $43.20%$ is oxygen. Since the percentages add up to $"100%"$,...

1 Answers 1 views
A compound that contains only nitrogen and oxygen is 30.4% N by mass; the molar mass of the compound is 92 g/mol. What is the empirical formula and the molecular formula of the compound?

In $100* g$ of this there are $30.4* g$ $N$, and the balance $O$. We divide thru by the atomic masses in order to approach the empirical formula: $(30.4*g)/(14.01*g*mol^-1)$ $=$...

1 Answers 1 views
A 5.325 g sample of methyl benzoate, a compound in perfumes, was found to contain 3.758 g of carbon, 0.316 g of hydrogen, and 1.251 g of oxygen. What is the empirical formula? If its molar mass is about 136 g/mol, what is its molecular formula?

I propose an interesting alternative to the classic approach of finding the empirical formula first, then using the molar mass to find the molecular formula. More specifically, we will find...

1 Answers 1 views
A sample of a compound contains 7.89 g potassium, 2.42 g carbon, and 9.69 g oxygen. What is the empirical and molecular formulas of this compound, which has a molar mass of 198.22 g/mol?

Let the molecular formula be $K_mC_nO_p$ The weight of the sample is $m=7.89+2.42+9.69=20g$ The number of moles of each element is Potassium $=7.89/39.1=0.2 $ Carbon $=2.42/12=0.2$ Oxygen $=9.69/16=0.6$ Divide...

1 Answers 1 views
A sample of a compound weighs 200 grams and contains only carbon, hydrogen, oxygen, and nitrogen. By analysis, it contains 97.56 grams of carbon, 52.03 g of oxygen and the rest is nitrogen. How do you its empirical formula?

You haven't given us the constituent percentage of hydrogen. Would you review the question? Once we have $%H$ we can address the question.

1 Answers 1 views
An organic compound contains 20.0 % Carbon, 6.66% Hydrogen, 47.33% Nitrogen and the rest was Oxygen. Its molar mass is 60 gm. The molecular formula of the compound is? (A) $CH_4 N_2 O$ (B) $CH_2 NO_2$ (C) $C_2H_6 NO$ (D) $CH_18 NO$

With all these empirical formula problems, we assume that there are $100*g$ of unknown compound, and work out the empirical formula appropriately: $"Moles of carbon:"=(20.0*g)/(12.011*g*mol^-1)=1.67*mol.$ $"Moles of hydrogen:"=(6.66*g)/(1.00794*g*mol^-1)=6.61*mol.$ $"Moles of...

1 Answers 1 views
A compound with a molar mass of 180 g is made of carbon, hydrogen and oxygen. When it is burned, the products are 44.0 g of $CO_2$, and 8 g of $H_2O$. Based on this, what are the empirical formula and the molecular formula of the compound?

To solve this problem, we look at the amount of products. 44 g of $CO_2$ is one mole of this compound, and so, contains one mole of carbon atoms and...

1 Answers 1 views
Microanalysis of an organic compound containing carbon, hydrogen, and oxygen, gives $62.6%*C$, and $4.21%*H$. What is the empirical formula of the compound?

We assume a $100*g$ mass of compound, and thus.... $"Moles of carbon"=(62.6*g)/(12.011*g*mol^-1)=5.21*mol*C$ $"Moles of hydrogen"=(4.21*g)/(1.00794*g*mol^-1)=4.16*mol*H$ $"Moles of oxygen"=(33.3*g)/(15.999*g*mol^-1)=2.08*mol*H$ In each case, we have divided the mass of element by the...

1 Answers 1 views
X