Answer:
Benzoic acid= 37.16%
Naphthalene = 24.43%
3-Nitroaniline= 29.38%
Explanation:
Data given:
percentage recovery of benzonic acid = 9.75/26.24 * 100 = 37.16%
Percentage recovery of napthalene = 6.41/26.24 * 100 = 24.43%
Percentage recovery of 3-nitroaniline = 7.71/26.24 * 100 = 29.38%
The concentration ratio of conjugate acid to conjugate base for a 20 mM solution at pH 7.0 of an amino acid is 20:1.
Required:
a. What is the pK of the side chain?
b. What amino acid might this be?
Answer:
a. 8.3= pKa of the aminoacid
b. Cysteine
Explanation:
The pH of an acid can be obtained using the H-H equation:
pH = pKa + log [A-] / [HA]
Where pH is the pH of the buffer = 7.0
pKa is the pka of the conjugate acid = ?
[A-] / [HA] is the ratio between conjugate base and conjugate acid. As the ratio of conjugate acid to conjugate base = 20:1, the [A-] / [HA] = 1/20
Replacing:
7 = pKa + log 1/20
7 = pKa - 1.30
7+1.30 = 8.3 = pKa of the aminoacid
The only aminoacid with a side chain with pKa = 8.3 is:
Cysteine. Allowing its identification.
The speed of light_____ meters per second
☛ 299,792,458 meters per second.
The majority of metals are found within
The majority of metals are found in ores.
But a few such as copper, gold, platinum, and silver frequently occur in the free state because they do not readily react with other elements.
Nitrogen and hydrogen react to form ammonia, like this:N2(g)+3H2(g)→2NH3(g)Use this chemical equation to answer the questions below.Suppose 135, mmol of N₂ and 405, mmol of H₂ are added to an empty flask, How much N₂ will be in the flask at equilibrium? a. Noneb. Some, but less than 135, mmol.c. 135,mmold. More than 135, mmol.Suppose 235, mmol of NH₃ are added to an empty flask, How much N₂ will be in the flask at equilibrium? a. Noneb. Some, but less than 118, mmol.c. 118,mmold. More than 118, mmol.
Answer:
Option A is correct, there will be no N2 left in the flask
Explanation:
Step 1 : Data given
Number of moles of N2 = 135 mmol = 0.135 mol
Number of moles of H2 = 405 mmol = 0.405 mol
Step 2: The reaction
N2(g)+3H2(g)→2NH3(g)
Step 3:
For 1 mol N2 we need 3 moles H2 to produce 2 moles NH3
Both will completely react. There is no limiting reactant.
There will be produce 0.270 moles NH3.
Option A is correct, there will be no N2 left in the flask
Fill in the blanks with each titration term with its definition.
a. Solution of an unknown concentration that has another solution slowly added to it ________________
b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them ______________
c. A reagent added to the analyte solution that changes color when the reaction is complete ______________
d. Glassware that allows a solution to be precisely and slowly added to another solution _____________
e. Solution of known concentration that is slowly added to a solution of unknown concentration ________________
f. When the required amount of one solution has been added to the second solution to complete the reaction ____________
Answer:
Fill in the blanks with each titration term with its definition.
a. Solution of an unknown concentration that has another solution slowly added to it ________________
b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them ______________
c. A reagent added to the analyte solution that changes color when the reaction is complete ______________
d. Glassware that allows a solution to be precisely and slowly added to another solution _____________
e. Solution of known concentration that is slowly added to a solution of unknown concentration ________________
f. When the required amount of one solution has been added to the second solution to complete the reaction ____________
Explanation:
a. Solution of an unknown concentration that has another solution slowly added to it is called analyte.
b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them is called titration.
c. A reagent added to the analyte solution that changes color when the reaction is complete is called an indicator.
d. Glassware that allows a solution to be precisely and slowly added to another solution is called a pipette.
e. Solution of known concentration that is slowly added to a solution of unknown concentration is called titrant.
f. When the required amount of one solution has been added to the second solution to complete the reaction is called neutralization.
Question 5: Energy Sources (12 points)
A. There are many ways to produce electricity. List two energy sources that generate electricity via a chemical reaction, and explain what kind of reaction each uses. (6 points)
B. Ethane is a common component of energy sources. Write the chemical formula for ethane. (2 points)
C. Write and balance the chemical equation for the combustion reaction of ethane. (4 points)
Answer:
See explanation
Explanation:
It is possible to generate electricity through a chemical reaction in two ways;
I) use of a voltaic cell where spontaneous chemical processes produce electrical energy.
ii) use of an electrolytic cell where non spontaneous chemical processes produce electrical energy.
The chemical formula of ethane is C2H6
The balanced chemical equation for the combustion of ethane is as follows;
C2H6 + 7/2 O2 ------> 2CO2 + 3H2O
Arrange aluminum, boron, nitrogen, and phosphorous in order of increasing electronegativity.
a. Al < N < P < B
b. Al < B < P < N
c. N < P < B < Al
d. B < Al < N < P
Answer:
Option b.
Al < B < P < N
Explanation:
Electronegativity is the capacity of an atom to attract electrons.
Usually, if we look at the periodic table, the elements in the left are the ones with the least electronegativity, and as we go to the right, the electronegativity increases (this is not really exact)
There are a lot of tables of electronegativity that can be used here, we can find that:
element: electronegativity:
N 3.04
B 2.04
P 2.19
Al 1.61
So, the order from least to greatest is:
Al, B, P, N
Then the correct option is:
b: Al < B < P < N
A Bronsted-Lowry acid is defined as a substance that ________. A Bronsted-Lowry acid is defined as a substance that ________. increases Ka when placed in H2O increases [OH-] when placed in H2O acts as a proton donor acts as a proton acceptor decreases [H ] when placed in H2O
Answer: A Bronsted-Lowry acid is defined as a substance that acts as a proton donor.
Explanation:
A substance that is able to donate a proton or hydrogen ion to another substance is a Bronsted-Lowry acid.
For example, HCl is a Bronsted-Lowry acid as it dissociates to give a hydrogen ion.
[tex]HCl \rightleftharpoons H^{+} + Cl^{-}[/tex]
Thus, we can conclude that a Bronsted-Lowry acid is defined as a substance that acts as a proton donor.
Which of the following is the correct way to balance the following chemical question:
2SnO2 + 4H2 -> 2Sn + 4H2O
SnO2 + 2H2 -> Sn + 2H2O
a. Both equation I and II are balanced, but equation I is the correct way to write the balanced equation.
b. Can you divide equation II by another factor and still have it be correct? Why or why not?
c. In a complete sentence, write down a method you could use to determine if an equation is written in the correct way.
Answer:
i have no answer for part A
part B
the one that has a 4 can be divided by 2 because reducing
part c
you can determine if an equation is written in the correct way by balancing the equation as if it had not been done already.
CAN YOU PLEASE HELP ME
When Pt electrodes are used in the electrolysis of Kl(aq), a number of reactions are possible at the electrodes. Using a standard reduction potentials table predict which reaction is most likely to occur at the anode
anode is oxidation
so look at the reduction potential for Pt and Kl
the one with the smaller reduction potential will undergo oxidation
the one with the larger reduction potential will undergo reduction
you have to flip the equation that undergoes oxidation because the reduction table always gives reduction equations
8.7 Two products are formed in the following reaction in a 50:50 mixture. Would the resulting solution be optically active
Answer:
Yes. The solution would be optically active.
Explanation:
Diastereomer are defined as the image that is non mirror and non -identical. It is made up of two stereoisomers. They are formed when the two stereoisomers or more than two stereoisomers of the compound have the same configuration at the equivalent stereocenters.
In the given context, as the product given is a diastereomeric mixture, the product would have an optical activity in total.
So the answer is Yes.
ype the correct answer in the box.
Calculate the density of the substance.
A sample of a substance has a mass of 4.2 grams and a volume of 6 milliliters. The density of this substance is grams/milliliter.
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Explanation:
here is your answer. Hope it helps
1.Using the absorbance of the spinach extract and the equation of the trendline, determine the concentration of the extract solution. Report the concentration in moles/L (M).
2. Calculate the number of rams of chlorophyll-a in the 25ml, spinach solution.
3. Calculate the concentration of the chloropyhll-a soultion in spinach (mg chlorophyll-a/g spinach)
Trendline: y=1609x + .0055
Absorbance spinach extract lamda max: .329
Absorbacne spinach extract, 750 nm: .023
Corrected absorbance: .306
Mass of Spinach: .1876g Total Volume of spinach: 25mL
Answer:
Explanation:
From the given information:
We are to make use of the spinach absorbance extract which is the corrected absorbance (y) = 0.306
And also the trendline equation:
y = 1609x + 0.0055
where,
x = absorbance of the spinach extract.
∴
0.306 = 1609x + 0.0055
collecting the like terms
0.306 - 0.0055 = 1609x
0.3005 = 1609x
x = 0.3005/1609
x = 1.8676 × 10⁻⁴
x ≅ 0.0002 M
No. of grams for the chlorophyll can be computed as follows:
recall that:
molar mass of chlorophyll = 893.5 g/mol
the volume = 25ml = (25/1000) L = 0.025 L
∴
In spinach solution, the no. of grams for the chlorophyll:
= (0.0002) mol/L × (893.5 g/mol) × (0.025) L
= 0.0044675 g
≅ 0.0045 g
In the spinach, the concentration of chlorophyll = no of grams of chlorophyll/ mass of the spinach
= 4.5 mg/0.1876 g
= 23.987 mg/g
≅ 24 mg/g
From the given information:
We are to make use of the spinach absorbance extract which is the corrected absorbance (y) = 0.306ChlorophyllChlorophyll is any member of the class of the green pigments involved in the photosynthesis process.
And also the trendline equation:
y = 1609x + 0.0055
where,
x = absorbance of the spinach extract.
so 0.306 = 1609x + 0.0055
collecting the like terms
0.306 - 0.0055 = 1609x
0.3005 = 1609x
x = 0.3005/1609
x = 1.8676 × 10⁻⁴
x ≅ 0.0002 M
2. No.of grams for the chlorophyll can be computed as follows:
recall that:
molar mass of chlorophyll = 893.5 g/mol
The volume = 25ml = (25/1000) L = 0.025 L
Therefore:
In spinach solution, the no. of grams for the chlorophyll:
= (0.0002) mol/L × (893.5 g/mol) × (0.025) L
= 0.0044675 g
≅ 0.0045 g
3. In the spinach, the concentration of chlorophyll = no of grams of chlorophyll/ mass of the spinach
= 4.5 mg/0.1876 g
= 23.987 mg/g
≅ 24 mg/g
Read more about chlorophyll here:
https://brainly.com/question/3529377
How is each triglyceride different from the others?
Each triglyceride is different from the others on the basis of presence of fatty acids in it.
What are triglycerides?Triglycerides is a kind of fat and derivative of ester which is formed by the combination of glycerol and three fatty acids.
So in the triglyceride molecule three sub divided parts are present due to the presence of three fatty acids groups and these fatty acids will make difference in each triglyceride molecules.
Hence of fatty acids in triglyceride molecule makes it different from other.
To know more about triglyceride, visit the below link:
https://brainly.com/question/1147557
Answer:
It has different fatty acids.
Explanation:
This is a signature of triglycerides
State two conditions necessary for an esterification reaction to take place
Explanation:
Esterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.
Answer:
The Esterification ProcessThe Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.
The Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.Once the -OH has been removed, the hydrogen on the alcohol can be removed and that oxygen can be connected to the carbon. Because the oxygen was already connected to a carbon, it is now connected to a carbon on both sides, and an ester is formed.
The Esterification ProcessEsterification occurs when a carboxylic acid reacts with an alcohol. This reaction can only occur in the presence of an acid catalyst and heat. It takes a lot of energy to remove the -OH from the carboxylic acid, so a catalyst and heat are needed to produce the necessary energy.Once the -OH has been removed, the hydrogen on the alcohol can be removed and that oxygen can be connected to the carbon. Because the oxygen was already connected to a carbon, it is now connected to a carbon on both sides, and an ester is formed.The methyl acetate that was formed is an ester. In this image, the green circle represents what was the carboxylic acid (in this case acetic acid), and the red circle represents what was the alcohol (in this case methanol):
This reaction lost an -OH from the carboxylic acid and a hydrogen from the alcohol. These two also combine to form water. So any esterification reaction will also form water as a side product.
Liquid ethyl mercaptan, C2H6S, has a density of 0.84 g/mL. Assuming that the combustion of this compound produces only CO2 , H2O, and SO2 , what masses of each of these three products would be produced in the combustion of 3.15 mL of ethyl mercaptan
Answer:
Mass CO2 = 3.75 grams
Mass H2O = 2.30 grams
Mass SO2 = 2.73 grams
Explanation:
Step 1: Data given
Density of Liquid ethyl mercaptan, C2H6S = 0.84 g/mL
Volume of ethyl mercaptan = 3.15 mL
Step 2: The reaction
2C2H6S + 9O2 → 4CO2 + 6H2O + 2SO2
Step 3: Calculate mass of ethyl mercaptan
Mass = Volume * density
Mass ethyl mercaptan = 3.15 mL * 0.84 g/mL
Mass ethyl mercaptan = 2.646 grams
Step 4: Calculate moles ethyl mercaptan
Moles = mass / molar mass
Moles ethyl mercaptan = 2.646 grams / 62.13 g/mol
Moles ethyl mercaptan = 0.04259 moles
Step 5: Calculate moles of other products
For 2 moles ethyl mercaptan we need 9 moles O2 to produce 4 moles CO2, 6 moles H2O and 2 moles SO2
For 0.04259 moles we need 0.1917 moles O2 to produce:
2*0.04259 = 0.08518 moles CO2
3*0.04259 = 0.1278 moles H2O
1*0.04259 = 0.04259 moles SO2
Step 6: Calculate mass produced
Mass = moles * molar mass
Mass CO2 = 0.08518 moles * 44.01 g/mol
Mass CO2 = 3.75 grams
Mass H2O = 0.1278 moles * 18.02 g/mol
Mass H2O = 2.30 grams
Mass SO2 = 0.04259 moles * 64.07 g/mol
Mass SO2 = 2.73 grams
What mass of NaOH would need to be dissolved in 500.0 mL of water to produce a solution with a pH of 12.40
Answer:
0.5024 g
Explanation:
Step 1: Calculate the concentration of H⁺
We will use the definition of pH.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog -12.40 = 3.981 × 10⁻¹³ M
Step 2: Calculate the concentration of OH⁻
We will use the ionic product of water expression.
[H⁺] [OH⁻] = 10⁻¹⁴
[OH⁻] = 10⁻¹⁴/[H⁺] = 10⁻¹⁴/3.981 × 10⁻¹³ = 0.02512 M
Step 3: Calculate the initial concentration of NaOH
NaOH is a strong base and the molar ratio of NaOH to OH⁻is 1:1. Thus, the initial concentration of NaOH is 1/1 × 0.02512 M = 0.02512 M.
Step 4: Calculate the moles of NaOH
We will use the definition of molarity.
M = moles of NaOH/liters of solution
moles of NaOH = M × liters of solution
moles of NaOH = 0.02512 mol/L × 0.5000 L = 0.01256 mol
Step 5: Calculate the mass of 0.01256 moles of NaOH
The molar mass of NaOH is 40.00 g/mol.
0.01256 mol × 40.00 g/mol = 0.5024 g
when a polar bond is formed between 2 atoms which atom receives a partial positive charge
Answer:
The less electronegative atom
Explanation:
Water contains polar bonds. Water is made up of oxygen and hydrogen. Oxygen is more electronegative then hydrogen so it is partial negative (because electron spend more time around oxygen in the polar bond), whereas, hydrogen has a partial positive charge as it is less electronegative (electrons spend less time around hydrogen in this polar bond).
How much would the freezing point of water decrease if 4 mol of sugar were added to 1kg of water?
Answer:
7.44 C is the answer of the question.
Explanation:
All of the orbitals in the 3d subshell have a principal quantum number value of 3, an angular momentum quantum number of:_____.
Answer:
According to the four quantum numbers; magnetic quantum number is the same as angular momentum quantum number. so the answer is 5
Explanation:
for d subshell angular momentum "d" is assigned a value of : m= 2(range from negative to positive i.e, -2 to 2) so we have [ -2, -1 ,0, 1 , 2] which concludes to 5.
Give your familiarity for following terms
1. roasting 2. smelting 4. zone refining 5. polling
Answer:
The roasting process is a delicate combination of art and science . Roasters are familiar with how the beans look and the smells Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests .Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests.Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals.In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining. In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. ... For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining.Polling is the process where the computer or controlling device waits for an external device to check for its readiness or state, often with low-level hardware. For example, when a printer is connected via a parallel port, the computer waits until the printer has received the next character.Explanation:
hope it heloed
How many grams of h2o are needed to produce 45g of NO
Perform the following operation and express the answer in scientific notation.
7.296×10² ÷ 9.6×10^-9
Answer:
7.6×10¹⁰
Explanation:
7.296×10²÷9.6×10⁻⁹
To solve such problem,
We group the whole number ans solved seperately and also group the indices and solve the seperately
Step1 : 7.296/9.6 = 0.76
Step 2: applying the law of indices,
10²÷10⁻⁹ = 10⁽²⁺⁹⁾ = 10¹¹
Therefore,
7.296×10²÷9.6×10⁻⁹ = 0.76×10¹¹ = 7.6×10¹⁰
Answer the following questions: (Questions about titration)
a. Why is it important to keep the NaOH solution covered at all times?
b. How will the molarity of NaOH solution be affected by its continued exposure to the atmosphere?
c. The pale pink color of the titration solution at the end point will fade to colorless after several minutes when exposed to the atmosphere. Account for this color change.
d. What volume (in mL) of 0.293 M Ba(OH)2 is required to neutralize 25.00 mL of 0.200M HNO3?
Answer:
Following are the solution to the given question:
Explanation:
For question a:
It is prevented that the atmospheric [tex]CO_2[/tex] through dissolving in the solution and make carbonic acid [tex](H_2CO_3)[/tex] which reacts with the [tex]NaOH:[/tex]
[tex]CO_2+ H_20\to H_2CO_3\\\\H_2CO_3 + NaOH \to NaHCO_3 +H_2O\\\\H_2CO_3 + 2 NaOH \to Na_2CO_3 + 2H_2O\\\\[/tex]
For question b:
For this, the [tex]NaOH[/tex] reacts with the dissolved [tex]CO_2[/tex] so, the molarity of the [tex]NaOH[/tex] will be decreased.
For question C:
In this, the Phenolphthalein is pink in the basic solution[tex](high \ pH)[/tex] and colorless throughout the acidic solution[tex](low\ pH)[/tex].
if the solution is exposed from the atmosphere, the [tex]CO_2[/tex] is from the air dissolving in the solution, and making the [tex]H_2CO_3[/tex] that gives the [tex]H^{+}\ ions[/tex]
[tex]\to[/tex] lower pH.
[tex]\to[/tex] colorless phenolphthalein
For question D:
[tex]Ba(OH)_2 + 2 HNO_3 \to Ba(NO_3)_2+ 2H_2O\\\\[/tex]
Calculating the moles of[tex]HNO_3 = volume \times \text{concentration of} HNO_3\\\\[/tex]
[tex]= \frac{25}{1000} \times 0.200\\\\= 0.005\ mol\\\\[/tex]
Calculating the moles of [tex]Ba(OH)_2= \frac{1}{2} \times\text{moles of}\ HNO_3\\\\[/tex]
[tex]=\frac{1}{2} \times 0.005\\\\= 0.0025 \ mol\\\\[/tex]
Calculating the volume of [tex]Ba(OH)_2=\frac{moles}{concentration\ of\ Ba(OH)_2}[/tex]
[tex]=\frac{0.0025}{0.0293}\\\\=0.08532\ L\\\\= 85.32 \ mL\\\\= 85.3\ mL[/tex]
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One main difference between the heating of gases on the one hand and solids or liquids on the other is that ___________________. One main difference between the heating of gases on the one hand and solids or liquids on the other is that ___________________. heating of gases depends not only on the temperature difference, but also on the process as well as the amount of gas present. heating of gases depends on temperature difference as well as the amount of gas present. specific heat is not defined for gases. heat cannot be exchanged with gases.
Answer:
heating of gases depends not only on the temperature difference, but also on the process as well as the amount of gas present.
Explanation:
The work done when a gas is heated does not only depends on the initial and final states of the gas but also on the process used to achieve the change of state of the gas.
Several processes can be applied in changing the state of a gas such as; adiabatic process, isobaric process, isochoric process and isothermal process.
Hence, the heating of a gas, depends not only on the temperature difference, as well as the amount of gas present according to the ideal gas laws but also on the process used to achieve the change of state.
One of the students in lab decided to use two fractionating columns (one on top of the other) instead of just one. How would this:_________.
a) affect the separation between hexane and heptane?
b) affect the yield of recovered pure hexane?
c) affect the yield of recovered pure heptane.
Explain your reasoning.
Answer:
See detailed explanation.
Explanation:
Hello there!
In this case, according to the given description, it turns out possible for us to infer that the second fractionating column on top of the first one will favor the light product, in this case hexane as it has the lowest boiling point and molar mass; in such a way, we can tell the following:
a) The separation between hexane and heptane will be increased as a purer hexane-rich product will be obtained on the top of the second column.
b) Will be increased as well, because the second column will remove more heptane.
c) Also, more pure heptane will be obtained on the bottom of the two columns, yet the most favored yield will be that of hexane.
All of the aforementioned is possible due to the fact that the second column will remove the amount of heptane that could not be removed on the top of the first column by taking the vapor-liquid equilibrium further from the first column's maximum separation, which is known as distillation sequences.
Regards!
Select the statement that best answers the following question What effect does the anion of an ionic compound have on the appearance of the solution?
a. The anion affects the intensity of the color more than the color of the solution.
b. The anion affects the color of the solution more than the intensity of the color.
c. The anion does not affect the color or color intensity of the solution.
d. The anion only affects the intensity of the color in a solution.
Answer:
b. The anion affects the color of the solution more than the intensity of the color.
Explanation:
An ionic compound is one that is made up of ions held together by electrostatic forces. The ions are made up of positively charged ions known as cations and negatively charged ions known as anions. In compounds with a high ionic attribute, anions produce colorless compounds. But compounds that have less ionic attributes produce deeper colors like black and red. When in solutions, ionic compounds take on color and this is because of the anion that absorbs infrared light energy.
Para formar bronce, se mezclan 150g de cobre a 1100°C y 35g de estaño a 560°C. Determine la temperatura final del sistema.
Dato: Ce Cu: 0,093 cal/gºC; Ce Sn: 0,060 cal/gºC
URGENTEEEE
Answer:
La temperatura final del sistema es 1029,346 °C.
Explanation:
Asumamos que el sistema conformado por el cobre y el estaño no tiene interacciones con sus alrededores. Por la Primera Ley de la Termodinámica, el cobre cede calor al estaño con tal de alcanzar el equilibrio térmico. El cobre se encuentra inicialmente en su punto de fusión, mientras que el estaño está por encima de ese punto, de modo que la transferencia de calor es esencialmente sensible:
[tex]m_{Cu}\cdot c_{Cu}\cdot (T-T_{Cu}) = m_{Sn}\cdot c_{Sn}\cdot (T_{Sn}-T)[/tex]
[tex](m_{Cu}\cdot c_{Cu} + m_{Sn}\cdot c_{Sn})\cdot T = m_{Sn}\cdot c_{Sn}\cdot T_{Sn} + m_{Cu}\cdot c_{Cu}\cdot T_{Cu}[/tex]
[tex]T = \frac{m_{Sn}\cdot c_{Sn}\cdot T_{Sn}+m_{Cu}\cdot c_{Cu}\cdot T_{Cu}}{m_{Cu}\cdot c_{Cu}+m_{Sn}\cdot c_{Sn}}[/tex] (1)
Donde:
[tex]m_{Sn}[/tex] - Masa del estaño, en gramos.
[tex]m_{Cu}[/tex] - Masa del cobre, en gramos.
[tex]c_{Sn}[/tex] - Calor específico del estaño, en calorías por gramo-grados Celsius.
[tex]c_{Cu}[/tex] - Calor específico del cobre, en calorías por gramo-grados Celsius.
[tex]T_{Sn}[/tex] - Temperatura inicial del estaño, en grados Celsius.
[tex]T_{Cu}[/tex] - Temperatura inicial del cobre, en grados Celsius.
Si sabemos que [tex]m_{Cu} = 150\,g[/tex], [tex]m_{Sn} = 35\,g[/tex], [tex]c_{Cu} = 0,093\,\frac{cal}{g\cdot ^{\circ}C}[/tex], [tex]c_{Sn} = 0,060\,\frac{cal}{g\cdot ^{\circ}C}[/tex], [tex]T_{Sn} = 560\,^{\circ}C[/tex] y [tex]T_{Cu} = 1100\,^{\circ}C[/tex], entonces la temperatura final del sistema es:
[tex]T = \frac{(35\,g)\cdot \left(0,060\,\frac{cal}{g\cdot ^{\circ}C} \right)\cdot (560\,^{\circ}C)+(150\,g)\cdot \left(0,093\,\frac{cal}{g\cdot ^{\circ}C} \right)\cdot (1100\,^{\circ}C)}{(35\,g)\cdot \left(0,060\,\frac{cal}{g\cdot ^{\circ}C} \right)+(150\,g)\cdot \left(0,093\,\frac{cal}{g\cdot ^{\circ}C} \right)}[/tex]
[tex]T = 1029,346\,^{\circ}C[/tex]
La temperatura final del sistema es 1029,346 °C.
Calculate the percent dissociation of benzoic acid C6H5CO2H in a 1.3M aqueous solution of the stuff. You may find some useful data in the ALEKS Data resource. Round your answer to 2 significant digits.
Answer:
the percent dissociation is 0.69 %
Explanation:
Given the data in the question;
benzoic acid C₆H₅CO₂H
C₆H₅COOH[tex]_{(aq)[/tex] ⇔ C₆H₅COO[tex]_{-(aq)[/tex] + H[tex]_{+(aq)[/tex]
Ka = [C₆H₅COO- ][ H+ ] / [ C₆H₅COOH ] = 6.28 × 10⁻⁵
given that it dissociated in a 1.3 M aqueous solution.
so Initial concentration is;
[ C₆H₅COOH ] = 1.3
[C₆H₅COO- ] = 0
[ H+ ] = 0
Change in concentration
[ C₆H₅COOH ] = -x
[C₆H₅COO- ] = +x
[ H+ ] = +x
Concentration equilibrium
[ C₆H₅COOH ] = 1.3 - x
[C₆H₅COO- ] = +x
[ H+ ] = +x
Hence,
x² / ( 1.3 - x ) = 6.28 × 10⁻⁵
6.28 × 10⁻⁵( 1.3 - x ) = x²
8.164 × 10⁻⁵ - 6.28 × 10⁻⁵x = x²
x² + 6.28 × 10⁻⁵x - 8.164 × 10⁻⁵ = 0
solve for x
ax² + bx - c = 0
x = [ -b ± √( b² - 4ac ) ] / [ 2a ]
we substitute
x = [ -6.28 × 10⁻⁵ ± √( (6.28 × 10⁻⁵)² - (4 × 1 × -8.164 × 10⁻⁵ ) ) ] / [ 2 × 1 ]
x = [ -6.28 × 10⁻⁵ ± 0.01807 ] / [ 2]
x = [ -6.28 × 10⁻⁵ - 0.01807 ] / [ 2] or [ -6.28 × 10⁻⁵ + 0.01807 ] / [ 2]
x = -0.0090664 or 0.0090036
so x = 0.0090036
hence
[ H+ ] = +x = 0.0090036 M
[C₆H₅COO- ] = +x = 0.0090036 M
Initial concentration of [ C₆H₅COOH ] = 1.3 M
concentration of C₆H₅COOH dissociated = 0.0090036 M
percent dissociation of C₆H₅COOH will be;
⇒ ( 0.0090036 M / 1.3 M ) × 100 = 0.69 %
Therefore, the percent dissociation is 0.69 %