Need help on two questions (electron configuration and stoichiometry

In summary: The smallest ratio for each element will give you the empirical formula.In summary, the original compound analyzed in this conversation contains H, N, O, and C, with an original sample weight of 1.3957 grams. When burned in excess oxygen, it forms 2.24 grams of CO2 and 0.04 grams of H are evaluated in the original sample. The grams of oxygen in the original sample can be found by subtracting the weights of N, C, and H from the original sample weight. The original compound contains 28.84% N, which is equivalent to 0.0403 grams. To find the grams of C, you can convert the grams of CO2 to moles and then
  • #1
roxy6
1
0
A compound is analyzed and it contains H,N,O and C. The original sample is 1.3957 grams. The sample is burned in excess oxygen to form 2.24 grams of CO2. 0.04 grams H is evaluated in the original sample.

a. What are the grams of oxygen in the original sample?
b. The original compound contains 28.84% N, how many grams of N are there?
c. How many grams of C are in the original compound?
d. What is the empirical formula for this compound?

How would you do this step by step and what are the solutions?

I was only able to get part B which was .0403 grams i believe?

I have a midterm tomorrow and need urgent help.

Thank you
 
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  • #2
roxy6 said:
A compound is analyzed and it contains H,N,O and C. The original sample is 1.3957 grams. The sample is burned in excess oxygen to form 2.24 grams of CO2. 0.04 grams H is evaluated in the original sample.

a. What are the grams of oxygen in the original sample?
b. The original compound contains 28.84% N, how many grams of N are there?
c. How many grams of C are in the original compound?
d. What is the empirical formula for this compound?

How would you do this step by step and what are the solutions?

I was only able to get part B which was .0403 grams i believe?

I have a midterm tomorrow and need urgent help.

Thank you

b- correct
c- how many moles of C are in 2.24 grams of CO2? What is that in grams?
a- Subtract b, c, and 0.04 grams H from the original sample weight. That gives you the amount of oxygen in the original compound.
d-after you find everything in grams you can covert it to moles. Find the ratios between each government.
 
  • #3
for reaching out for assistance with your questions. I am happy to help guide you through the problem-solving process and provide solutions.

a. To determine the grams of oxygen in the original sample, we need to use stoichiometry. First, we need to determine the number of moles of CO2 formed in the reaction. We know that 2.24 grams of CO2 was formed, and the molar mass of CO2 is 44.01 g/mol. Using this information, we can calculate the number of moles of CO2 formed:
2.24 g CO2 x (1 mol CO2/44.01 g CO2) = 0.0509 mol CO2

Next, we need to use the balanced chemical equation for the combustion of the compound to determine the moles of oxygen consumed in the reaction. The balanced equation is:
C x H y N z O a + O2 → CO2 + H2O + N2

From the equation, we can see that for every 1 mole of CO2 formed, 1 mole of oxygen is consumed. Therefore, the number of moles of oxygen consumed is also 0.0509 mol.

Now, we can use the molar mass of oxygen (16.00 g/mol) to calculate the grams of oxygen in the original sample:
0.0509 mol O2 x (16.00 g O2/1 mol O2) = 0.8144 g O2

Therefore, there were 0.8144 grams of oxygen in the original sample.

b. As you correctly calculated, the grams of hydrogen in the original sample is 0.0403 g. To determine the grams of nitrogen in the original sample, we can use the percent composition given (28.84%). This means that 28.84% of the original sample is nitrogen, and the remaining 71.16% is made up of the other elements. We can set up the following equation to solve for the grams of nitrogen:
0.0403 g H x (100%/28.84%) = 0.1398 g N

Therefore, there were 0.1398 grams of nitrogen in the original sample.

c. To determine the grams of carbon in the original sample, we can use the same approach as in part b. The percent composition of carbon can be calculated by subtracting the percentages of the other elements
 

Related to Need help on two questions (electron configuration and stoichiometry

1. What is electron configuration?

Electron configuration refers to the arrangement of electrons in an atom's energy levels or orbitals. It is represented using a series of numbers and letters that indicate the energy level, sublevel, and number of electrons in each sublevel.

2. How do you determine the electron configuration of an atom?

The electron configuration of an atom can be determined by using the Aufbau principle, Hund's rule, and the Pauli exclusion principle. The Aufbau principle states that electrons fill the lowest energy orbitals first, while Hund's rule states that electrons will occupy separate orbitals within the same sublevel before pairing up. The Pauli exclusion principle states that each orbital can hold a maximum of two electrons with opposite spins.

3. What is stoichiometry?

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. It involves using mathematical calculations to determine the amount of reactants needed or the amount of products formed in a chemical reaction.

4. How do you calculate the stoichiometric ratio?

The stoichiometric ratio is calculated by dividing the number of moles of one substance by the number of moles of another substance in a balanced chemical equation. This ratio can then be used to determine the amount of each substance needed or produced in the reaction.

5. What is the difference between theoretical and actual yield in stoichiometry?

Theoretical yield is the maximum amount of product that can be formed in a chemical reaction based on the stoichiometric calculations. Actual yield, on the other hand, is the amount of product that is actually obtained in a laboratory experiment. The actual yield is often less than the theoretical yield due to factors such as incomplete reactions, side reactions, or human error.

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