Answer:
D
Explanation:
A buffer solution contains 0.345 M acetic acid and 0.377 M sodium acetate . If 0.0613 moles of potassium hydroxide are added to 250 mL of this buffer, what is the pH of the resulting solution ? (Assume that the volume does not change upon adding potassium hydroxide. )
Answer:
pH = 5.54
Explanation:
The pH of a buffer solution is given by the Henderson-Hasselbach (H-H) equation:
pH = pKa + log[tex]\frac{[CH_3COO^-]}{[CH_3COOH]}[/tex]For acetic acid, pKa = 4.75.
We calculate the original number of moles for acetic acid and acetate, using the given concentrations and volume:
CH₃COO⁻ ⇒ 0.377 M * 0.250 L = 0.0942 mol CH₃COO⁻ CH₃COOH ⇒ 0.345 M * 0.250 L = 0.0862 mol CH₃COOHThe number of CH₃COO⁻ moles will increase with the added moles of KOH while the number of CH₃COOH moles will decrease by the same amount.
Now we use the H-H equation to calculate the new pH, by using the new concentrations:
pH = 4.75 + log[tex]\frac{(0.0942+0.0613)mol/0.250L}{(0.0862-0.0613)mol/0.250L}[/tex] = 5.54h-h+cl+cl____2h-cl... calculate the energy needed to break the bond
What change in volume results if 170.0 mL of gas is cooled from 30.0 °C to 20.0 °C? (CHARLES LAW)
Answer:
164.4 L
Explanation:
use charles' law formula Volume 1 over Temp. 1 equaled to Volume 2 over Temp. 2
What is the volume of an object with the mass of 7.9 grams in the density of 2.28g/ml.
Answer:
3.7mL is the volume of the object
Explanation:
To convert the mass of any object to volume we must use density that is defined as the ratio between mass of the object and the space that is occupying. For an object that weighs 7.9g and the density is 2.28g/mL, the volume is:
7.9g * (1mL / 2.28mL) =
3.7mL is the volume of the objectSelect the structure that corresponds
to the name:
3,5,6-trichloro-2-heptanol
Answer:C both
Explanation:
The Structure that correspondsto the name: 3,5,6-trichloro-2-heptanol is C both.
How nomenclature is done in organic compound ? First name the principal carbon chain and also check type of bonds single or double present on the carbon chain. Name the functional group according to Seniority table. Name the substituent alphabetically. Both are isomers∵ all are substituent and OH alcohol is added on the principal carbon chain both names are suggested.
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For a particular reaction at 135.4
°C, Δ=−775.41 kJ/mol
, and Δ=817.91 J/(mol⋅K)
.
Calculate ΔG for this reaction at 12.7
°C.
Answer:
[tex]\Delta G=-675.38 \frac{kJ}{mol}[/tex]
Explanation:
Hello!
In this case, for this problem, it is possible to use the thermodynamic definition of the Gibbs free energy:
[tex]\Delta G=\Delta H-T\Delta S[/tex]
Whereas G, H and S can be assumed as constant over T; thus, we can calculate H at 135.4 °C:
[tex]\Delta H=\Delta G+T\Delta S\\\\\Delta H=-775.41\frac{kJ}{mol}+(135.4+273.15)K*(0.81791\frac{kJ}{mol*K} )\\\\\Delta H=-441.58\frac{kJ}{mol}[/tex]
Now, we can calculate the Gibbs free energy at 12.7 °C as shown below:
[tex]\Delta G=-441.58\frac{kJ}{mol} -(12.7+273.15)K*0.81791\frac{kJ}{mol*K}\\\\\Delta G=-675.38 \frac{kJ}{mol}[/tex]
Best regards!
In which of these two states of matter is water the least dense: solid or liquid?
Answer:
liquid
Explanation:
it is only the thing in what water can disslove
Angus, Hereford, and Holstein are common types of ___
breeds.
NEED HELP NOW
Answer:Cattle
Explanation:Cattle
Why is boiling water a physical change
Answer:
it is cleaning the water and heating it
Answer:
When boiling the water, the water will begin to evaporate and thats the physical change.
The graph below shows distance over time. Which of these situations
could be represented by this graph?
Pls answer quick
Answer:
the second option
Explanation:
look at the distance where the meet up at the house and the go to school
Calculate the molarity of 32.5 g of MgS in 935 mL of solution.
before phase change: molecules move around each other 15. The medicine in the diagram above has molecules that are moving around each other. The doctor needs to slow down the molecules enough to cause a phase change. How will she do this, and how will this affect the medicine? I She transfers energy ... a into the medicine until it is a liquid. b) into the medicine until it is a gas. C out of the medicine until it is a solid. d out of the medicine until it is a liquid. LE 1 21 Illuminate Education, Inc.
Answer:
She transfers energy out of the medicine until it is solid. So the answer would be C.
Explanation:
According to the forces of attraction , molecules can be slowed down by moving out of the medicine until it is a solid , it will decrease the rate of absorption of medicine.
What are forces of attraction?Forces of attraction is a force by which atoms in a molecule combine. it is basically an attractive force in nature. It can act between an ion and an atom as well.It varies for different states of matter that is solids, liquids and gases.
The forces of attraction are maximum in solids as the molecules present in solid are tightly held while it is minimum in gases as the molecules are far apart . The forces of attraction in liquids is intermediate of solids and gases.
The physical properties such as melting point, boiling point, density are all dependent on forces of attraction which exists in the substances.
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Which of the following would make it easier for a plant to do photosynthesis?
O Colorful flowers
O Very large leaves.
Very tall stem.
O Short roots
How do you think our understanding of genes might affect doctors ability to treat or prevent disease in the future?
Answer:
dentifying genetic variants Genome sequencing has the potential to improve the diagnosis of conditions caused by changes in the DNA and indicate what treatments may be most effective. Importantly, it may also red-flag treatments likely to cause adverse reactions.
Explanation:
Answer:
Identifying genetic variants Genome sequencing has the potential to improve the diagnosis of conditions caused by changes in the DNA and indicate what treatments may be most effective. Importantly, it may also red-flag treatments likely to cause adverse reactions.
Explanation:
Equal chemical equations!
H2 + Cl2 ----> HCl
P4 + O2 ----> P4O10
Na + Cl2 ----> NaCl
CH4 + O2 ----> CO2 + H2O
Answer:Na+Cl2---->NaCl
Explanation:
Answer:
I've balanced the equations.
They are in the attached image.
The values in red are the added number to make the equation balanced .
A room is filled with 45.0 kg of Nitrogen gas (N2). If the temperature of the gas is 26.0 degrees C and has a pressure of 794 torr, what is the volume of the room, in gallons? (1 gal = 3.785 L)
Hi this is not a answer but I just wanna warn you so listen to these person just in case u see that scammer
Question 21 of 25
Which of the following best describes an Arrhenius acid-base reaction?
O A. Acid + base = H+ + OH-
B. Acid + base = salt + water
C. Acid + base = conjugate base + conjugate acid
D. Acid + base =
H20
Answer:
B. Acid + base = salt + water
Explanation:
In accordance to the proposal of a scientist called Svante Arrhenius, an acid is a substance that increases the H+ concentration of a solution by dissociating into it while the base increases the OH- concentration of a solution by dissociating into it. Furthermore, Arrhenius stated that this two ions combine in an aqueous solution to give water.
Hence, Arrhenius acid-base reaction is the combination of an acid and base to produce salt and water as products. That is; Acid + base = salt + water.
Explain the difference in percent ionization in the two solutions. Match the words in the left column to the appropriate blanks in the sentences on the right.
a. left.
b. right.
c. larger.
d. smaller.
e. common ion effect.
f. formation of H3O+ by the salt.
g. addition of a weak base.
1. The percent ionization in the potassium formate solution is____than that in pure water because of the____.
2. The equilibrium for the dissociation of formic acid is shifted to the____by this addition, and a____amount of acid dissociates.
Answer:
1. The percent ionization in the potassium formate solution is smaller than that in pure water because of the common ion effect.
2. The equilibrium for the dissociation of formic acid is shifted to the left by this addition, and a smaller amount of acid dissociates.
Explanation:
The common ion effect refers to the effect on equilibrium that is observed when an ion that is already contained in the solution (common ion) is added to a solution. The addition of a common generally results in a shift in equilibrium positiont towards the removal of the common ion from solution. This is according to Le Châtelier's Principle which states that if an equilibrium becomes unbalanced, the reaction will shift to restore the balance.
The common ion effect decreases the ionization of a weak acid as the addition of more of an ion that is a product of this equilibrium will shift equilibrium towards removal of the ion.
Adding a common ion also decreases solubility, as the reaction shifts toward the left in order to annul the constraint of the excess ion in the product side of equilibrium.
The percent ionization in the potassium formate solution is smaller than that in pure water because of the Common ion effect. The equilibrium for the dissociation of formic acid is shifted to the left by this addition, and a smaller amount of acid dissociates.
What is Equilibrium law?Equilibrium law states that if any external effect is applied on the equilibrium state of any chemical reaction, then the equilibrium will shift towards that side where the effect will decrease.
Common ion effect occurs when the already present ion in the solution is further added to the solution which increases the concentration of that ion in the solution and equilibrium will shift towards the side where common ion effect will decreases.
That's why the percentage of ionization in the potassium formate solution is less than the percentage of ionization in pure water. And due to common ion effect equilibrium will shift towards the left side where dissociation decreases and the concentration of ions is also decreases.
Hence correct options are smaller, common ion effect, left and smaller.
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what is the reaction type for Zn(C2H3O2)2 + Na3(PO4)?
Answer: This is a precipitation reaction: Zn 3(PO 4) 2 is the formed precipitate.
Explanation:
Go this Answer form, (chemequations.com)
Im Glad I helped! =)
0.24 moles of a gaseous product from a reaction is collected in a 25.0-L container at a pressure of 300.0 kPa. Determine the temperature (in °C) at which the gas was collected.
Answer:
3428.58 °C
Explanation:
We'll begin by converting 300 KPa to atm. This can be obtained as follow:
101.325 KPa = 1 atm
Therefore,
300 KPa = 300 KPa × 1 atm / 101.325 KPa
300 KPa = 2.96 atm
Next, we shall determine the temperature. This can be obtained as follow:
Number of mole (n) = 0.24 mole
Volume (V) = 25 L
Pressure (P) = 2.96 atm
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =?
PV = nRT
2.96 × 25 = 0.24 × 0.0821 × T
74 = 0.24 × 0.0821 × T
Divide both side by 0.25 × 0.0821
T = 74 / (0.24 × 0.0821)
T = 3755.58 K
Finally, we shall convert 3755.58 K to °C. This can be obtained as followb:
T(°C) = T(K) – 273
T(K) = 3755.58 K
T(°C) = 3755.58 – 273
T(°C) = 3428.58 °C
Thus, the temperature at which the gas was collected is 3428.58 °C
I need to know why the particles at the surface in the image below have surface tension while the particles below the surface do not.
Determine the number of grams of carbon-14 remaining in this sample at 17,100 years.
Answer: I need help
Explanation:
what is fermentation
Fermentation is a metabolic method that creates chemical changes in natural substrates through the action of enzymes.
Explanation: hope this helps :)
Choose the options below that are true. (select all that apply) Select all that apply:
a. The rate law for a given reaction can be determined from a knowledge of the rate-determining step in that reaction's mechanism.
b. The rate laws of all chemical reactions can be determined directly from their net chemical equations.
c. The rate laws of bimolecular elementary reactions are second order overall.
d. The rate law for a given reaction can be determined from its reaction mechanism,
Answer:
a, c are true statements
Explanation:
First statement concludes that only the slower stage or the rate deciding phase of the reaction allows for the rate law to be calculated. This is true
The second declaration is not valid in all regards, because we can not evaluate the correct rate law by just observing the net equation. It needs to be determined experimentally.
In the third statement, most of the bimolecular reactions are second order in general, since two reactants exist. Hence, it is true
The fourth declaration is wrong. To measure the rate of each elemental phase accompanying the response, we must observe the rates
why does the bridge buckle when there isn't a joint?
Is thier any answer choices?
a 75.0 balloon hold 59.3g of neon gas. the gas is released until the balloon volume is 61.8 L. how many grams of neon escaped?
Answer:
A rigid tank holds a 2.91 moles of gas at a pressure of 772 kPa. What will the pressure be if another 1.09 moles of gas is added?
Explanation:
How do I balance coefficient equations
Answer:
In order to balance the chemical equation, you need to make sure the number of atoms of each element on the reactant side is equal to the number of atoms of each element on the product side. In order make both sides equal, you will need to multiply the number of atoms in each element until both sides are equal.
Answer: When you balance a chemical equation, you change coefficients. You never change subscripts. A coefficient is a whole number multiplier. To balance a chemical equation, you add these whole number multipliers (coefficients) to make sure that there are the same number of atoms on each side of the arrow.
Explanation:
Which structure is unique to vertebrates?
limbs
brain
skin
backbone
Answer:
Backbone
Explanation:
Organisms that have backbones are known as vertebrates, while the ones without a backbone are classified as invertebrates.
The structure that is unique to vertebrates is the backbone.
What are vertebrates?Vertebrate, also known as the Craniata. It is the type of animal where it should be predominant of subphylum. Moreover, it contains the backbones. The animal or the organism that have the backbones that we called as the vertebrates however the organism or animal that does not have any backbone is known as the invertebrates
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FOR BRAINLIST!!!
A Student 1
B Student 2
C Student 3
D Student 4
Answer:
Student 2
Explanation:
I am not 100% sure but I would say Student 2
:)
i agree with the other answer
What is a coefficient?
Answer:
in math it's " a numerical or constant quantity placed before and multiplying the variable in an algebraic expression (e.g. 4 in 4x y)."
In physics " a multiplier or factor that measures some property."
Explanation:
hope this is helpful!
Answer:
A coefficient is the number before a variable
Explanation:
A numerical or constant quantity placed before and multiplying the variable in an algebraic expression