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
vovikov84 [41]
2 years ago
11

Stearic acid (C18H36O2) is a fatty acid, a molecule with a long hydrocarbon chain and an organic acid group (COOH) at the end. I

t is used to make cosmetics, ointments, soaps, and candles and is found in animal tissue as part of many saturated fats. In fact, when you eat meat, you are ingesting some fats containing stearic acid. ( of C18H36O2 = –948 kJ/mol, CO2=-393.5kJ/mol, H2O=-241.826kJ/mol).
Calculate the heat (q) released in kcal when 2.831 g of stearic acid is burned completely.
Chemistry
1 answer:
aev [14]2 years ago
6 0

The molar mass of stearic acid is 18*AC+36*AH+2*AO=18*12+36*1+16*2=284g/mol.

n=m/M=2.831/284=0.01 moles

C18H36O2+27O2-->18CO2+18H2O

we have 18*0.01=0.18 moles of CO2

18*0.01=0.18 moles of H2O

0.01*948=9.48kJ from stearic acid

0.18*393.5=70.83kJ from CO2

0.18*241.826=43.52kJ from H2O

9.48+70.83+43.52=123.83kJ

123.83*4.184=518.10kcal

You might be interested in
Is the largest of Saturn's moons, Charon, larger than Mercury?​
vazorg [7]

Answer:

no, Charon is significantly smaller than Mercury

4 0
1 year ago
Arterial blood contains about 0.25 g of oxygen per liter at 37°C and standard atmospheric pressure. Under these conditions, the
Olin [163]

Firstly we need to determine the partial pressure of O2:

\begin{gathered} P_{O_2}=X\times P_T \\ P_{O_2}:partial\text{ }pressure \\ X:mole\text{ }fraction \\ P_T:total\text{ }pressure \\  \\ P_{O_2}=0.209\times0.35\text{ }atm \\ P_{O_2}=0.073\text{ }atm \end{gathered}

We will now use the Henry's Law equation to determine the solubility of the gas:

\begin{gathered} c=K_H\times P_{O_2} \\ c:solubility\text{ }or\text{ }concentration\text{ }of\text{ }the\text{ }gas(M) \\ K_H:Henry^{\prime}sLawconstant=3.7\times10^{-2}M\text{ }atm^{-1} \\ P_{O_2}:partial\text{ }pressure\text{ }of\text{ }the\text{ }gas=0.073atm \\  \\ c=3.7\times10^{-2}M\text{ }atm^{-1}\times0.073 \\ c=2.7\times10^{-3}M \end{gathered}

Answer: Solubility is 2.7x10^-3 M

6 0
8 months ago
In the absence of sodium methoxide, the same alkyl bromide gives a different product. Draw an arrowpushing mechanism to account
hoa [83]

Answer:

See explanation below

Explanation:

The question is incomplete, cause you are not providing the structure. However, I found the question and it's attached in picture 1.

Now, according to this reaction and the product given, we can see that we have sustitution reaction. In the absence of sodium methoxide, the reaction it's no longer in basic medium, so the sustitution reaction that it's promoted here it's not an Sn2 reaction as part a), but instead a Sn1 reaction, and in this we can have the presence of carbocation. What happen here then?, well, the bromine leaves the molecule leaving a secondary carbocation there, but the neighbour carbon (The one in the cycle) has a more stable carbocation, so one atom of hydrogen from that carbon migrates to the carbon with the carbocation to stabilize that carbon, and the result is a tertiary carbocation. When this happens, the methanol can easily go there and form the product.

For question 6a, as it was stated before, the mechanism in that reaction is a Sn2, however, we can have conditions for an E2 reaction and form an alkene. This can be done, cause the extoxide can substract the atoms of hydrogens from either the carbon of the cycle or the terminal methyl of the molecule and will form two different products of elimination. The product formed in greater quantities will be the one where the negative charge is more stable, in this case, in the primary carbon of the methyl it's more stable there, so product 1 will be formed more (See picture 2)

For question 6b, same principle of 6a, when the hydrogen migrates to the 2nd carbocation to form a tertiary carbocation the methanol will promove an E1 reaction with the vecinal carbons and form two eliminations products. See picture 2 for mechanism of reaction.

3 0
3 years ago
Why do all the elements in Group 16 share similar properties?
geniusboy [140]
D. They all have the same number of valence electrons.
5 0
3 years ago
It takes 49.0J to raise the temperature of an 11.5g piece of unknown metal from 13.0?C to 24.3?C. What is the specific heat for
svet-max [94.6K]

Answer:

c = 0.377 J/g.°C

c = 0.2350 J/g.°C

J = 27.3 J

Explanation:

We can calculate the heat (Q) absorbed or released by a substance using the following expression.

Q = c × m × ΔT

where,

c: specific heat

m: mass

ΔT: change in the temperature

<em>It takes 49.0J to raise the temperature of an 11.5g piece of unknown metal from 13.0°C to 24.3°C. What is the specific heat for the metal? Express your answer numerically, in J/g.°C</em>

Q = c × m × ΔT

49.0 J = c × 11.5 g × (24.3°C - 13.0°C)

c = 0.377 J/g.°C

<em>The molar heat capacity of silver is 25.35 J/mol.°C. How much energy would it take to raise the temperature of 11.5g of silver by 10.1°C? Express your answer numerically, in Joules. What is the specific heat of silver?</em>

<em />

The molar mass of silver is 107.87 g/mol. The specific heat of silver is:

\frac{25.35J}{mol.\° C} .\frac{mol}{107.87g} =0.2350J/g.\° C

Q = c × m × ΔT

Q = (0.2350 J/g.°C) × 11.5 g × 10.1°C = 27.3 J

5 0
3 years ago
Other questions:
  • A solution is prepared by dissolving 33.0 milligrams of sodium chloride in 1000. L of water. Assume a final volume of 1000. lite
    7·1 answer
  • Which of the following requires the most energy to get started?
    14·1 answer
  • Given the following equation: 4 NH3 (g)5 O2 (g) &gt;4 NO (g) + 6 H20 (I) How many moles of NH3 is required to react with 25.7 gr
    8·1 answer
  • Which values are written in proper scientific notation? Check all that apply.
    10·2 answers
  • What branch of chemistry is most concerned with the study of carbon compounds
    13·1 answer
  • If a substance has a high hydronium concentration, the substance has a ____ pH.
    15·1 answer
  • Enthalpy of reaction described for 3Mg+N2----&gt;Mg3N2?
    6·1 answer
  • Easy points if you actually try :)<br> How's your day going today?<br><br> Stay great! &lt;3
    14·2 answers
  • 02. Two great pe birds are morati Both birth have a ne
    10·2 answers
  • The total pressure in a container is 37.9 psi. There are two gases in the container. Gas A exerts a pressure of 18.4 psi. What i
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!