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
iogann1982 [59]
3 years ago
9

Find the boiling point temperature at 760 torr of an isomer of octane, c8h18, if its enthalpy of vaporization is 38,210 j mol-1

and its vapor pressure at 110.0°c is 638.43 torr.
Chemistry
1 answer:
mixas84 [53]3 years ago
7 0

According to Clausius-Clayperon equation,

ln(\frac{P_{1} }{P_{2} }) = \frac{delta H_{vap} }{R} (\frac{1}{T_{2} }-\frac{1}{T_{1} }   )

P_{1}is the vapor pressure at boiling point = 760 torr

P_{2} is the vapor pressure at T_{2} =638.43 torr

TemperatureT_{2} = 110.0^{0}C + 273 = 383 K

ΔH_{vap} = 38210 J/mol

Plugging in the values, we get

ln(\frac{P_{1} }{P_{2} }) = \frac{delta H_{vap} }{R} (\frac{1}{T_{2} }-\frac{1}{T_{1} }   )

ln\frac{760 torr}{638.43 torr} =\frac{38210 J/mol}{8.314 J/(mol.K)} (\frac{1}{383 K}-\frac{1}{T_{1} }

T_{1} = 389 K

Therefore, the boiling point of octane = 389 K - 273 = 116^{0}C

You might be interested in
Which element will chemically combine with fluorine to combine salt?
Natali5045456 [20]

Answer:

When an atom of sodium and an atom of fluorine combine to form the salt, sodium fluoride, an ionic bond, is formed.

Explanation:

8 0
2 years ago
Complete combustion of 7.40 g of a hydrocarbon produced 22.4 g of CO2 and 11.5 g of H2O. What is the empirical formula for the h
cluponka [151]
<span>C2H5 First, you need to figure out the relative ratios of moles of carbon and hydrogen. You do this by first looking up the atomic weight of carbon, hydrogen, and oxygen. Then you use those atomic weights to calculate the molar masses of H2O and CO2. Carbon = 12.0107 Hydrogen = 1.00794 Oxygen = 15.999 Molar mass of H2O = 2 * 1.00794 + 15.999 = 18.01488 Molar mass of CO2 = 12.0107 + 2 * 15.999 = 44.0087 Now using the calculated molar masses, determine how many moles of each product was generated. You do this by dividing the given mass by the molar mass. moles H2O = 11.5 g / 18.01488 g/mole = 0.638361 moles moles CO2 = 22.4 g / 44.0087 g/mole = 0.50899 moles The number of moles of carbon is the same as the number of moles of CO2 since there's just 1 carbon atom per CO2 molecule. Since there's 2 hydrogen atoms per molecule of H2O, you need to multiply the number of moles of H2O by 2 to get the number of moles of hydrogen. moles C = 0.50899 moles H = 0.638361 * 2 = 1.276722 We can double check our math by multiplying the calculated number of moles of carbon and hydrogen by their respective atomic weights and see if we get the original mass of the hydrocarbon. total mass = 0.50899 * 12.0107 + 1.276722 * 1.00794 = 7.400185 7.400185 is more than close enough to 7.40 given rounding errors, so the double check worked. Now to find the empirical formula we need to find a ratio of small integers that comes close to the ratio of moles of carbon and hydrogen. 0.50899 / 1.276722 = 0.398669 0.398669 is extremely close to 4/10, so let's reduce that ratio by dividing both top and bottom by 2 giving 2/5. Since the number of moles of carbon was on top, that ratio implies that the empirical formula for this unknown hydrocarbon is C2H5</span>
3 0
3 years ago
Compare which element would have larger first ionization energy: an alkali metal in Period 2 or an alkali metal in Period 4?
maria [59]

Answer:

An alkali metal present in period 2 have larger first ionization energy.

Explanation:

Ionization energy:

The amount of energy required to remove the electron from the atom is called ionization energy.

Trend along period:

As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction. The electrons are pull towards the nucleus and valance shell get closer to the nucleus. As a result of this greater nuclear attraction atomic radius decreases and ionization energy increases because it is very difficult to remove the electron from atom and more energy is required.

Trend along group:

As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased.

As the size of atom increases the ionization energy from top to bottom also  decreases because it becomes easier to remove the electron because of less nuclear attraction and as more electrons are added the outer electrons becomes more shielded and away from nucleus.  Thus alkali metal present in period 2 have larger ionization energy because of more nuclear attraction as compared to the alkali metal present in period 4.

6 0
3 years ago
According to the Bohr model of an atom, what happens when an electron moves from the second energy level to the third energy lev
kati45 [8]
<span>Energy is absorbed and then released to form an emission line.

When electrons absorb energy they increase there energy level. This is only temporary and the excited electron then relaxes back down to its original energy level releasing energy.

The energy is released in form of EM radiation of a specific frequency depending on the element and how many energy levels the electron relaxes. 
This forms an emission line.</span><span />
4 0
3 years ago
Read 2 more answers
How do weather models predict the weather?
strojnjashka [21]

Answer:

<em>Weather forecasters often discuss the models they use to help predict the weather. ... Weather observations (pressure, wind, temperature and moisture) obtained from ground sensors and weather satellites are fed into these equations. The observations are brought into the models in a process known as data assimilation.</em>

Explanation:

<h2><em>I </em><em>hope</em><em> this</em><em> helps</em><em>!</em></h2>
4 0
2 years ago
Other questions:
  • How many moles are in 15 grams of calcium
    5·2 answers
  • The attraction of like water molecules to each other is called _________.
    15·1 answer
  • Which of the following is correctly balanced redox half reaction? Group of answer choices A. 14H+ + 9e- + Cr2O72- ⟶ Cr3+ + 7H2O
    13·1 answer
  • What is the pH of a 0.1 M phosphate buffer (pKa = 6.86) that contains equal amounts of acid and conjugate base?
    5·1 answer
  • The concentration of iodide ions in a saturated solution of lead (ii) iodide is __________ m. the solubility product constant of
    11·1 answer
  • Suppose now that you wanted to determine the density of a small crystal to confirm that it is sulfur. From the literature, you k
    14·1 answer
  • Which phrase describes the mass of an ice cube? a. amount of space that the cube occupies
    10·2 answers
  • The results of an investigation are the<br> (Blank)
    14·1 answer
  • 8 bananas weigh 1pound and sale price is 4 pounds for $5. How much it cost me to buy 25 bananas?
    6·1 answer
  • Carbonate oxidation number
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!