1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
yaroslaw [1]
3 years ago
10

You perform a combustion analysis on a 255 mg sample of a substance that contains only C, H, and O, and you find that 561 mg of

CO2 is produced, along with 306 mm of H2O.
if the substance contains only C, H, and O, what is the empirical formula
if the molar mass of the compound is 180 g/mol what is the molecular formula of the compound
Chemistry
2 answers:
alexgriva [62]3 years ago
6 0

Answer:

molecular formula of compound =C₉H₂₄O₃

Explanation:

The compound contains only C,H and O

The combustion equation for carbon is:

C+O_{2}-->CO_{2}

Thus if we are obtaining 44g of carbon dioxide it means the amount of carbon is 12g.

If we are getting 1g of carbon dioxide, it means the amount of carbon = \frac{12}{44}g

If we are getting 561mg of carbon dioxide, it means the amount of carbon=\frac{12X561}{44}=153mg

So the mass of carbon in the given sample = 153mg

Percentage of carbon = \frac{massofcarbonX100}{massofsample}=\frac{153X100}{255}=60

The combustion equation for hydrogen is:

H_{2}+0.5O_{2}-->H_{2}O

Thus if we are obtaining 18g of water it means the amount of hydrogen is 2g.

If we are getting 1g of water, it means the amount of hydrogen = \frac{2}{18}g

If we are getting 306mg of water, it means the amount of hydrogen=\frac{2X306}{18}=34mg

So the mass of hydrogen in the given sample = 34mg

Percentage of hydrogen = \frac{massofhydrogenX100}{massofsample}=\frac{34X100}{255}=13.33

Percentage of oxygen=100-(60+13.33)=26.67%

The moles of each element in 100g of sample will be

moles of carbon = \frac{mass}{atomicmass}=\frac{60}{12}=5

moles of hydrogen = \frac{mass}{atomicmass}=\frac{13.33}{1}=13.33

moles of oxygen = \frac{mass}{atomicmass}=\frac{26.67}{16}=1.67

Let us divide all the moles with 1.67

moles of carbon = 3

moles of hydrogen = 8

moles of oxygen = 1

So the empirical formula of the compound would be:C₃H₈O

The empirical mass = 60

molar mass = 180g

So the molecular formula will be = \frac{180}{60}Xempiricalformula

molecular formula=C₉H₂₄O₃

zhuklara [117]3 years ago
5 0
The combustion of an organic compound is mostly written as,
                        CaHbOc + O2 --> CO2 + H2O
where a, b, and c are supposed to be the subscripts of the elements C, H, and O in the compound. Determining the number of moles of C and H in the product which is the same as that in the compound,
   (Carbon, C)   :   (561 mg) x (12/44) = 153 mg x (1 mmole/12 mg) = 12.75
   (Hydrogen, H) :  (306 mg) x (2/18)  = 34 mg x (1 mmole/1 mg) = 34 
   Calculating for amount of O in the sample,
(oxygen, O) = 255 - 153 mg - 34 mg = 68 mg x (1mmole/16 mg) = 4.25 
The empirical formula is therefore,
                        C(51/4)H34O17/4
                           C3H8O1
The molar mass of the empirical formula is 60. Therefore, the molecular formula of the compound is,
                                C9H24O3
You might be interested in
HELP ME PLEASE ASAP. I'LL MARK YOU BRAINLIEST <br> ITS NUMBER 23.
Ivanshal [37]

Answer:

The answer is A

Explanation:

5 0
3 years ago
True or false. elements in the same period have the same number of valence electrons
saul85 [17]
False. elements in the same period have the same number of shells while elements in the same group have the same number of valence electrons.
4 0
3 years ago
4. How many moles of KBr are found in 3 Liters of 0.4 M solution?
Allisa [31]

There are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.

<h3>HOW TO CALCULATE NUMBER OF MOLES?</h3>

The number of moles of a substance can be calculated by multiplying the molarity by the volume.

No. of moles = Molarity × volume

According to this question, 3L of a KBr solution are contained in a 0.4M.

no. of moles = 3L × 0.4M = 1.2moles

Therefore, there are 1.2 moles of KBr found in 3 Liters of 0.4 M solution.

Learn more about no. of moles at: brainly.com/question/14919968

4 0
2 years ago
If 26.2 grams of a pure compound contain 8.77 × 1022 molecules, what is the molecular weight of this compound? Answer in units o
Nataly [62]

Answer:

Mw = 179.845 g/mol

Explanation:

  • Mw [=] g/mol

∴ w = 26.2 g

∴ 1 mol = 6.02 E23 molecules.......Avogadro's number

⇒N° moles = 8.77 E22 molecules * ( mol / 6.02 E23 molecules ) = 0.146 mol

⇒ Mw = 26.2 g / 0.146 mol = 179.845 g/mol

3 0
3 years ago
GIVING BRAINLISTED
Mice21 [21]

Answer: one molecule of O2.

Explanation: sweet i just took a guess but I believe that if 3 o2 molecules - 2 h2 molecules I think that its just basic maths and it is C because 3-2 = 1 and its o2 remaining, sorry if I’m wrong.

6 0
3 years ago
Other questions:
  • Which statement most accurately describes the behavior of a catalyst?
    14·1 answer
  • which planet has the presence of liquid water, a period of rotation equal to 24 hours, and a solid inner core
    9·1 answer
  • Choose the most appropriate reagent(s) for producing the β-ketoester intermediate by alkylation of ethyl acetoacetate with 1-bro
    8·1 answer
  • What is the scientific notation of 38,802,000
    8·1 answer
  • Problem PageQuestion Ammonia will decompose into nitrogen and hydrogen at high temperature. An industrial chemist studying this
    5·1 answer
  • Which reacts with metals to form H2 gas
    15·1 answer
  • If the neutral solution was boiled to dryness, what would be the formula of the resulting salt.
    5·1 answer
  • How does a hydroelectric power plant convert energy?
    9·2 answers
  • A team of geologists is surveying on a mountain. They come across a newly formed stream. The stream is flowing at an average rat
    12·1 answer
  • Can bacteria reproduce
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!