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
Andrew [12]
3 years ago
13

Methanol, ethanol, and n−propanol are three common alcohols. When 1.00 g of each of these alcohols is burned in air, heat is lib

erated as indicated. Calculate the heats of combustion of these alcohols in kJ/mol.
Chemistry
1 answer:
KengaRu [80]3 years ago
5 0

Answer:

<u>For methanol:</u> Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)

<u>For ethanol: </u>Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)

<u>For propanol: </u>Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)

Explanation:

Given:

Mass of Methanol = 1.0 g

Mass of ethanol = 1.00 g

Mass of n-propanol = 1.00 g

<u>For methanol:</u>

2 CH₃OH + 3 O₂ ----> 2 CO₂ + 4 H₂O, ∆H₀ = -22.6 kJ/g  (negative sign signifies release of heat)

1 g of methanol on combustion gives 22.6 kJ of energy

Calculation of moles of methanol:

moles=\frac{Mass(m)}{Molar\ mass (M)}

Molar mass of methanol = 32.04 g/mol

Thus moles of methanol = 1 g/ (32.04 g/mol) = 0.0312 moles

Hence energy in kJ/mol:

<u>Heat of combustion = -22.6 kJ / 0.0312 moles = -724.3590 kJ/mol (negative sign signifies release of heat)</u>

<u></u>

<u>For ethanol:</u>

C₂H₅OH + 3 O₂ ----> 2 CO₂ + 3 H₂O, ∆H₀ = -29.7 kJ/g  (negative sign signifies release of heat)

1 g of ethanol on combustion gives 29.7 kJ of energy

Calculation of moles of ethanol:

moles=\frac{Mass(m)}{Molar\ mass (M)}

Molar mass of ethanol = 46.07 g/mol

Thus moles of ethanol = 1 g/ (46.07 g/mol) = 0.0217 moles

Hence energy in kJ/mol:

<u>Heat of combustion = -29.7 kJ / 0.0217 moles = -1368.6636 kJ/mol (negative sign signifies release of heat)</u>

<u></u>

<u>For propanol:</u>

2 C₃H₇OH + 9 O₂ ----> 6 CO₂ + 8 H₂O, ∆H₀ = -33.4 kJ/g , (negative sign signifies release of heat)

1 g of methanol on combustion gives 33.4 kJ of energy

Calculation of moles of methanol:

moles=\frac{Mass(m)}{Molar\ mass (M)}

Molar mass of methanol = 60.09 g/mol

Thus moles of methanol = 1 g/ (60.09 g/mol) = 0.0166 moles

Hence energy in kJ/mol:

<u>Heat of combustion = -33.4 kJ / 0.0166 moles = -2012.0482 kJ/mol (negative sign signifies release of heat)</u>

You might be interested in
Which of the following is not an example of a science? a.geology b.astrology c.astronomy d.ecology
Rasek [7]
I think it is b.astrology

6 0
3 years ago
the two stages that take place during distillation are. a.evaporation is folloeed by condensation. b.condensation followed by ev
ValentinkaMS [17]

Answer:

evapiration followed by condensation

3 0
2 years ago
Interpreting the periodic table
Goryan [66]

Here is an image of the periodic table. Hope this helps.

6 0
3 years ago
Scientists use what properties to help them identify and classify matter
Volgvan
Scientists use the physical and chemical properties to help them identify and classify matter. These physical and chemical properties are in a macro-perspective, in which these matter contains compounds, elements and atoms. Hence, matter can be classified in various ways, <span><span>
1.    </span>Atomic number either atomic mass each element has</span> 
<span><span>2.    </span>By substance of that matter either pure substance or mixed substance</span> <span>
3.    If they cannot reduce a certain substance into a much smaller quantified atomic structure then they they’ll use (2) to identify and classify it.</span>
5 0
3 years ago
Select the correct answer.
almond37 [142]

Answer:

D. 5 moles

Explanation:

C3H8 + 5O2 → 4H2O + 3CO2

            5 mol                 3 mol

So, to make 3 mol CO2    5 mol O2 are needed.

3 0
3 years ago
Other questions:
  • Sodium carbonate (NaCO3) is sometimes used as a water-softening agent. Suppose that a worker prepares a 0.730 M solution of NaCO
    8·1 answer
  • Nitroglycerin (c3h5n3o9) is a powerful explosive. its decomposition may be represented by 4c3h5n3o9 → 6n2 12co2 10h2o o2 this re
    6·2 answers
  • Which of the following best defines weather?
    11·1 answer
  • The temperature of the shadows of your increases with altitude because of the presence of?
    7·1 answer
  • Water initially present in a state where molecules are far apart. During a chnge of state, its molecules slow down. Which change
    8·1 answer
  • a laboratory procedure calls for making 510.0 mL of a 1.6 M KNO3 solution. How much KNO3 in grams is needed
    8·1 answer
  • What is the energy of one photon of red light that has a wavelength of 678 nm?
    13·1 answer
  • What is represented in each block of the periodic tables?
    7·1 answer
  • Miscible liquids that have different boiling points can be separated by _______.
    12·1 answer
  • Region where electrons are located within an atom, what is it??
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!