Gram for gram, fats in food have much more chemical energy than sugar. One component of fat is stearic acid, C18H36O2. When a sample of 1.02 g of stearic acid was burned completely in a bomb calorimeter, the temperature of the calorimeter rose by 4.26oC. The heat capacity of the calorimeter was 9.43 kJ/oC. Calculate the molar heat of combustion of stearic acid in kilojoules per mole.

Answers

Answer 1

Answer:

[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]

Explanation:

Given that:

mass (m) of the sample = 1.02 g

number of moles of stearic acid  [tex]=\dfrac{mass}{molar mass}[/tex]

[tex]= \dfrac{1.02 \ g}{284.49 \ g/mol} \\ \\ = 0.000358 \ moles[/tex]

The change in temp. [tex]\Delta T = 4.26^0 \ C[/tex]

heat capacity of the calorimeter (c) = 9.43 kJ/° C

Thus, heat due to reaction = cΔT

= 9.43 kJ/° C × 4.26° C

= 40.17 kJ

The heat in kJ/mol = [tex]\dfrac{40.17 \ kJ}{0.00358 \ mol}[/tex]

= 11204.23 kJ/mol

= 1.12 × 10⁴ kJ/mol

As a result of  the reaction is exothermic, the heat reaction of the  combustion is:

[tex]\mathbf{-1.12 \times 10^4 \ kJ/mol}[/tex]


Related Questions

Question 10
1 pts
Given the following balanced chemical equation:
2C2H10 + 902 +4CO2 + 10H2O
How many grams of C2H10 are needed to produce 150. g of water?
396 g
15.8 g
O 1420
O 56.8 g

Answers

Answer:

56.8 g

Explanation:

Your first conversion factor is the molar mass of H2O to convert from grams of water to moles. Your second conversion factor is the mole ratio of 2 mol C2H10 for every 10 mol H2O. Your last conversion factor is the molar mass of C2H10 to convert from moles back to grams.

150. g H2O • (1 mol H2O / 18.02 g H2O) • (2 mol C2H10 / 10 mol H2O) • (34.1 g C2H10 / 1 mol C2H10) = 56.8 g C2H10

How are cells organized?
A: Organs
B: Organelles
C: Tissues

Answers

Answer:

tissues,organs, organelles

What is the cation in KF?

Answers

Answer:

K, or Potassium

Explanation:

Think

about the physical properties used to identify elements as either metal,non-metals, or metalloids. Write

Imagine that you are asked to classify a group of elements as either metal, non-metals, or metalloids.

Explain how you would use their physical properties to accomplish this task.

Be sure to –Address the prompt, provide support, and conclude your thoughts. Write legibly and concisely.

Answers

Answer:

The elements can be classified as metals, nonmetals, or metalloids. ... Elements are further classified into metals, non-metals, and metalloids based on their properties, ... when they undergo chemical reactions They normally do not accept ... Most metal oxides are basic oxides and dissolve in water to form .

Explanation:

What is the energy of an electron in a Li+ ion when an electron moves from n = 2 to n =3?

Answers

when it gains an electrons is negatively charged so in this case I think it will be. -ion

Which type of substances do you separate into ions when writing the complete ionic equation?
a. Aqueous
b. Liquid
c. Gas
d. Solid

Answers

A.aqueous. Hope this helped:)

Answer:

a. Aqueous

Explanation:

Took the test

A wave travels at 22 m/s and has a wavelength of 11 m. What is its frequency

Answers

The answer is 2Hz

To calculate frequency, divide the number of times the event occurs by the length of time.

Psychology is the study of the human brain. A psychoanalyst is a person who
analyzes people's minds. What does the prefix psycho-mean?
A. Related to the brain
B. Related to studying
C. Related to science
D. Related to analysis

Answers

I think it’s A. Hope this helps
The answer to this question is A, hope you do well!

3.
Why do you suppose internet service costs a lot of money?

Answers

Answer:

Why does internet cost so much? Equipment and installation: One of the main reasons for internet prices to run high is the cost of equipment and installation in new service areas. Fiber optic cables are expensive, so fiber optic internet providers may have higher prices to recoup the costs of installing new lines.Apr 21, 2021Explanation:

Iodine shines like metals but is not metal what is its basis​

Answers

Answer:

Iodine is a non-metal, but it is lustrous (lustrous is the property of metal) in nature.

Which resources are unevenly distributed throughout Earth?

Select all that apply.

oil
soil
iron
oxygen

Answers

Answer:

Some natural resources like sunlight and wind are found everywhere, but other natural resources are unevenly distributed. Resources like oil, coal, and natural gas are only found where conditions were favorable to grow and preserve large quantities of animal or plant matter.

Explanation:

HELP PLEASEEEEEE ASAP

Answers

A condition in which bones become weak and brittle.

The body constantly absorbs and replaces bone tissue. With osteoporosis, new bone creation doesn't keep up with old bone removal.

thus 2) is correct.

a disease in which bone tissue becomes breakable and thin.

if it helps don't forget to like and Mark me

Ali says the climate of a town is rainy because it is raining outside today. Is she correct? In one or two sentences, explain why Ali is or is not correct about the climate of the town.

Answers

Answer:

Ali is incorrect.

Explanation:

Ali is wrong because the climate is a study of the weather pattern over a long period of time. You cannot look outside one day and determine the climate because the climate is long-term.

She could say the weather is rainy, because that is short term, but not the climate.

What would
happen to the
vultures if the
gazelle
decreased?

Answers

the vultures would eventually decrease also because the vultures feed off the dead gazelles

Answer:  If the gazelle population starts to decrease this could lead to some vultures not having enough food to eat

Explanation: This explains the obvious outcome of what would happen.

                     Hope you do well with what your doing :)

                                 Mark as Brainliest please :)

explain what is ment by solvent front​

Answers

Answer:

In paper chromatography, the wet moving edge of the solvent that progresses along the surface where the separation of the mixture is occurring.

Explanation:

I hope this helps and pls mark me brainliest :)

For each process, predict the sign on the entropy change and write a sentence or two to explain how to make this prediction without completing any mathematics. a.A solid melts. b.A vapor is converted into a solid. CH 117 Recitation Name: _________________________________ ~ 196 ~ c.A liquid freezes. d.A solid sublimes e.A vapor condenses to a liquid. f.A liquid boils. g.Dissolving a tablespoon of salt in water. h.Combustion of gasoline.

Answers

Answer: a. A solid melts: [tex]\Delta S=+ve[/tex]

b. a vapor is converted to solid: [tex]\Delta S=-ve[/tex]

c. a liquid freezes:  [tex]\Delta S=-ve[/tex]

d. A solid sublimes:  [tex]\Delta S=+ve[/tex]

e.  a vapor condenses to liquid :  [tex]\Delta S=-ve[/tex]

f. a liquid boils:   [tex]\Delta S=+ve[/tex]

g. dissolving a tablespoon of salt in water:  [tex]\Delta S=+ve[/tex]

h. combustion of gasoline:  [tex]\Delta S=+ve[/tex]

Explanation:

Entropy is the measure of randomness or disorder of a system. If a system moves from  an ordered arrangement to a disordered arrangement, the entropy change is negative and vice versa.

a. A solid melts: The solid is converting to liquid, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

b. a vapor is converted to solid: The gas  is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger Thus the entropy change [tex](\Delta S)[/tex] is negative.

c. a liquid freezes: The liquid is converting to solid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

d. A solid sublimes: The solid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

e.  a vapor condenses to liquid : The gas  is converting to liquid, thus the randomness is decreasing as the molecules are moving close and the intermolecular forces are getting stronger. Thus the entropy change [tex](\Delta S)[/tex] is negative.

f. a liquid boils: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

g. dissolving a tablespoon of salt in water: The solid is converting to ions , thus the randomness is increasing as the ions can move freely. Thus the entropy change [tex](\Delta S)[/tex] is positive.

h. combustion of gasoline: The liquid is converting to gas, thus the randomness is increasing as the molecules are moving away and the intermolecular forces are getting weaker. Thus the entropy change [tex](\Delta S)[/tex] is positive.

Which product will precipitate in the following reaction:
CaCl2 + Na2CrO4 → CaCrO4 + 2 NaCl
A.NaCl
B.CaCrO4
C.Na2CrO4
D.CaCl2

Answers

Answer:

a

Explanation:


Why are half-reactions used in redox reactions?

Answers

Answer:

Because a redox reaction holds for both oxidation and reduction.

One half equation is of oxidation and the other is of reduction.

When these two half equations are combined, we get an overall equation of the redox reaction.

Which combination of atoms is most likely to produce a compound
with ionic bonds?

Answers

Answer: In an ionic bond, one atom donates an electron to another atom. This stabilizes both atoms. Because one atom essentially gains an electron and the other loses it, an ionic bond is polar. In other words, one atom in the bond has a positive charge, while the other has a negative charge. Often, these atoms dissociate into their ions in water. Atoms that participate in ionic bonding have different electronegativity values from each other. If you look at a table of electronegativity values, it is apparent ionic bonding occurs between metals and nonmetals. Examples of compounds with ionic bonds include salt, such as table salt (NaCl).

What is a renewable resource on Earth?

minerals
coal
wind
petroleum

Answers

Answer:

Wind

Explanation:

Wind turbines make energy by the movement of the natural force on earth called 'wind' and renewable resources are resources that can be made from natural and environment-safe objects or things (e.g. Water, Geothermal Heat, The Sun, and Wind)

There is a bottle of KCl solution: the volume is 35 mL; its molarity is 3.0 M.

After diluting it into final volume 200 mL, what is the molarity (in M) now?

Answers

Answer:

0.525 M

Explanation:

As the problem deals with a dilution process, we can use the following formula:

C₁V₁=C₂V₂

Where subscript 1 stands for initial concentration and volume, while 2 stands for the final conditions. Meaning that in this case:

C₁ = 3.0 MV₁ = 35 mLC₂ = ?V₂ = 200 mL

We input the data given by the problem:

3.0 M * 35 mL = C₂ * 200 mL

And solve for C₂:

C₂ = 0.525 M

a freshwater stream flows into the ocean as shown in the diagram which statement correctly describes how the stream affects these salinity of the ocean


A- salinity increases because the stream adds salt to the ocean.

B- salinity decreases because the stream adds freshwater to the ocean

C- salinity increases because of stream adds freshwater to the ocean

D- salinity Remains the Same because the stream adds freshwater to the ocean ​

Answers

D - Salinity remains the same because the stream adds freshwater to the ocean

Which equation represents a double replacement reaction? A) 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g) B) 2Al(s) + 3Cl2(g) - 2AlCl3(s) C) 2AlCl3(s) + 2Al(s) + 3Cl2(g) D) AlCl3(aq) + 3KOH(aq) - Al(OH)3(s) + 3KCl(aq)​

Answers

Answer:

D) AlCl₃(aq) + 3 KOH(aq) → Al(OH)₃(s) + 3 KCl(aq)​

Explanation:

Which equation represents a double replacement reaction?

A) 2 Al(s) + 6 HCl(aq) → 2 AlCl₃(aq) + 3 H₂(g)

No, this is a single replacement reaction, in which Al replaces H in its acid.

B) 2 Al(s) + 3 Cl₂(g) → 2 AlCl₃(s)

No, this is a synthesis reaction, in which two simple substances combine to form a compound.

C) 2 AlCl₃(s) → 2 Al(s) + 3 Cl₂(g)

No, this is a decomposition reaction, in which a compound decomposes into simple substances.

D) AlCl₃(aq) + 3 KOH(aq) → Al(OH)₃(s) + 3 KCl(aq)​

Yes, this is a double replacement reaction, in which both reactants exchange their cations and anions.

A gas under a pressure of 9.86 kPa and at a temperature of 75°C occupies a 500.0L container. How many moles of gas are in the container?​

Answers

Answer:

1.7 mol

Explanation:

This is an ideal gas problem. So many units! That's the tip-off usually.

PV=nRT

First convert kPA to atm 1 atm=101.3 kPA so 9.86/101.3 = .097311 atm

(.097311 atm x 500L) = n · 0821 L·atm/mol·K · 348K

Do your multiplication then divide to get n alone and you should get 1.7 mol

Name (3) ways an animal can use energy from food?

Answers

Answer:

The food chain begins with the sun: plants get their energy by photosynthesizing sunlight into energy, and then herbivores eat those plants to get their energy. Carnivores who then eat the herbivores are getting that sunlight passed along from sun to plant to herbivore to carnivore.

1.
Why are kilometers not a good unit of measurement in space?
T.
2.
What distance measurement unit is used for objects within our solar system?
astronomical
units
3.
How many kilometers are in one astronomical unit?
4.
What distance measurement unit is used for objects outside of our solar
system?
_light
year!
5.
How many kilometers are in one light-year? I
How far away is the nearest star to Earth other than our Sun?
6.
7.
How far away is the center of the Milky Way Galaxy from Earth?
8.
What is the diameter of the Milky Way Galaxy?

Answers

because distances Between large objects in space are not VERY convenient

is pyramidal molecular geometry?

A. N2
B. H2O
C. NH3
D. CCL4

Answers

Answer:

[tex]\color{Blue}\huge\boxed{Question} [/tex]

Is pyramidal molecular geometry?

[tex]\color{Blue}\huge\boxed{Answer} [/tex]

B.H2O
it should be B.H2O!
goodluck please let me know if i’m wrong

The atomic musses of N (99. 64 percent) and 1N (0.36 percent) are 14.00307 amu and 15.0001 amu, respectively. Calculate the average atomic mass of nitrogen. The percentages in parentheses denote the relative abundances C01​?

Answers

Answer:

14.01 amu

Explanation:

Step 1: Given data

Isotope     Atomic mass (am)    Abundance (ab)

 ¹⁴N           14.00307 amu          99.64% (0.9964)

 ¹⁵N           15.0001 amu             0.36% (0.0036)

Step 2: Calculate the average atomic mass (aam) of nitrogen

We will use the following expression.

aam = ∑ am × ab

aam = 14.00307 amu × 0.9964 + 15.0001 amu × 0.0036 = 14.01 amu

Q3: Match the column A with Column B and write answer in Column C

Answers

Answer:

ok

Explanation:

1d

2c

3b

4a

What volume would 75.0g of oxygen gas occupy

Answers

Answer:

Explanation: It is already known that 1 mole of the gas( or 32g of O2) is equivalent to 22.4 Litres of the oxygen gas. So, 8g is equivalent to = (22.4/32) × 8 = 5.6 L of the gas.

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