Si tenemos una solución de ácido láctico 0.025M con un pH = 2.75. ¿Cuál es la constante de equilibrio Ka?

Answers

Answer 1

Answer:

La constante de equilibrio Ka del ácido láctico es 1.38x10⁻⁴.

Explanation:

El ácido láctico es un ácido débil cuya reacción de disociación es la siguiente:

CH₃CHOHCOOH + H₂O ⇄ CH₃CHOHCOO⁻ + H₃O⁺   (1)

0.025M - x                                        x                     x                    

La constante de acidez del ácido es:        

[tex] Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]} [/tex]

Sabemos que la concentración del ácido inicial es:

[CH₃CHOHCOOH] = 0.025 M    

Y que a partir del pH podemos hallar [H₃O⁺]:

[tex] pH = -log[H_{3}O^{+}] [/tex]

[tex] [H_{3}O^{+}] = 10^{-pH} = 10^{-2.75} = 1.78 \cdo 10^{-3} M [/tex]

Debido a que el ácido se disocia en agua para producir los iones CH₃CHOHCOO⁻ y H₃O⁺ de igual manera (según la reacción (1)), tenemos:

[CH₃CHOHCOO⁻] = [H₃O⁺] = 1.78x10⁻³ M

Y por esa misma disociación, la concentración del ácido en el equilibrio es:

[tex] [CH_{3}CHOHCOOH^{-}] = 0.025 M - 1.78 \cdo 10^{-3} M = 0.023 M [/tex]

Entonces, la constante de equilibrio Ka del ácido láctico es:

[tex] Ka = \frac{[CH_{3}CHOHCOOH^{-}][H_{3}O^{+}]}{[CH_{3}CHOHCOOH]} = \frac{(1.78 \cdo 10^{-3})^{2}}{0.023} = 1.38 \cdot 10^{-4} [/tex]          

 

Espero que te sea de utilidad!  


Related Questions

Please help me!!!!!!!!! :-]

Answers

its Aaaaaaaaaaaa....

A chemical equation representing the reaction of water (HOH) and hydrochloride acid (HCI) is shown.
HOH + HCl + Cl + H2O
Which of the following statements best explains the chemical action of the reactants in the equation?

Answers

Answer:

That is Hydrolysis reaction.

[tex]HCl _{(aq)} \: + \: _{(aq)} \: - - > \: H ^{ + }_{(aq)} \: + \: Cl {}^{ - } _{(aq)}[/tex]

PLEASE HELP!!!!
Which bond would be the least polar?
1) H-Br (hydrogen-bromine)
2) H-F (hydrogen-fluorine)
3) H-H (hydrogen-hydrogen)
4) H-O (hydrogen-oxygen)

Answers

Answer:

[tex]\boxed {\boxed {\sf 3. \ H-H}}[/tex]

Explanation:

To determine the polarity of a bond, we use the electronegativities of the individual atoms. The greater the difference, the more polar the bond.

1. H-Br

Hydrogen: 2.2 Bromine: 3.0

3.0-2.2=0.8

2. H-F

Hydrogen: 2.2 Fluorine: 4.0

4.0-2.2=1.8

3. H-H

Hydrogen: 2.2

2.2-2.2=0.0

4. H-O

Hydrogen: 2.2Oxygen: 3.4

3.4-2.2=1.2

As we can see, the lowest difference is in hydrogen hydrogen at 0.0. You may also recognize that because they are 2 atoms of the same element, the electronegativity is the same for both, so it will equal 0. Since the electronegativity is 0, this is a nonpolar bond.

The diagram below shows a group of water molecules.



The water molecules in the diagram are attracted to each other by

Answers

Answer:

hydrogen bonds, the positive and negative charges of the hydrogen and oxygen atoms that make up water molecules makes them attracted to one another.

The total pressure is distinct from the individual partial pressures of a mixture.
A. True
B. False

Answers

i believe it correct answer is true

Answer:

the answer is true :)

Study the map. Then use the drawing tool to create a model of how the two air masses look when they interact at front 1.

Answers

Answer: Picture

Explanation: I got it right

Answer:

2 and 3 look like a cold front in front of 1.

Explanation:

3 is an occluded front which occurs when a cold air mass devours a warm air mass and then collides with another cold mass. 2 is a warm air mass, and 1 is a cold air mass.

the minister in change of religious and charititable patreonage was known as

Answers

Answer:

sadr

Explanation:

Pls give brainlist

What charge is mobile within atoms and can be transferred between atoms?

Answers

Answer:

For example, when atoms lose or gain electrons they become charged particles called ions. Three ways electrons can be transferred are conduction, friction, and polarization. In each case, the total charge remains the same. This is the law of conservation of charge.

Explanation:

Scientists create models for all of the following reasons, EXCEPT

A - because a model can represent objects too large to comprehend

B - because a model can help to communicate their ideas

C - because a model is the only way to conduct an experiment

D - because a model is the only way to represent objects too small to see

Answers

A, B, and D are all valid uses of a model. C is incorrect; experiments can certainly be conducted wholly apart from models.

Thus, the correct answer choice here would be C.

Hydrogen is an element.
True
False

Answers

Answer:

True

Explanation:

Hydrogen is one of the most abundant elements in the universe so yes

Answer:

true

Explanation:

Hydrogen is an chemical element

what is a fossil? and what can a fossil tell us about an organism

Answers

Fossils are the geologically altered remains of a once-living organism and/or its behaviour. There are two main types: body fossils represent all or part of the organism's body, and trace fossils show evidence of the organism's behaviour. ... Scientists who study fossils are called paleontologists
a fossil is a peice of ancient things

Two hydrogen atoms covalently bond to form a hydrogen molecule.
What is true about the hydrogen molecule?

A-The hydrogen molecule can have more or less energy than the hydrogen atoms.

B-The hydrogen molecule has less energy than the two atoms.

C-The hydrogen molecule has the same energy as the two atoms.

Answers

Answer:

B

Explanation:

the energy of two separate hydrogen atoms decreases as they approach each other, and the single electrons on each atom are shared to form a covalent bond.

A sample of 1.00 moles of oxygen at 50°C and 98.6 kPa, occupies what volume?

Answers

Answer:

27.22 dm³

Explanation:

Given parameters:

number of moles = 1 mole

temperature= 50°C, in K gives 50+ 273 = 323K

Pressure= 98.6kpa in ATM, gives 0.973 ATM

Solution:

Since the unknown is the volume of gas, applying the ideal gas law will be appropriate in solving this problem.

The ideal gas law is mathematically expressed as,

Pv=nRT

where P is the pressure of the gas

V is the volume

n is the number of moles

R is the gas constant

T is the temperature

Input the parameters and solve for V,

0.973 x V = 1 x 0.082 x 323

V= 27.22 dm³

what is elastic energy ​

Answers

Answer:Elastic energy is energy stored in an object for temporary strain. It is basically potential energy.

In order to develop ideas for a new tennis racket, a design team visits three different sporting goods stores. What part of the desining process is this?

Answers

Answer:

Generate concept.

Explanation:

The process of designing includes many processes out of which the process of developing the idea for a new product is called Generate concept.

Product idea( concept) generation is a act that begins with a list of criteria set by the client regarding his necessities and preferences. Based on the criteria, concept generation aims to pinpoint a range of potential ideas and solutions that addresses those needs.

Great Sand Dunes National Park in Colorado is famous for its giant sand dunes. Sand dunes are landforms that are found in deserts and on beaches. Visitors to the park can surf down the dunes on sleds or boards.

Which process causes the shape of these giant dunes?

A. deposition
B. erosion
C. weathering
D. waves

Answers

either b or c :), i’m not quite sure

Please help me out here please

Answers

I believe it’s g also, when plates diverge (meaning they separate) And they go away from each other so as they push apart magma from the core of the earth rises and that’s how volcanoes are formed

What quantity of copper is deposited by the same quantity of electricity that deposited 9g of aluminum

Answers

Answer:

Mass of copper deposited = 31.75 g

Explanation:

According to Faraday's second law of electrolysis, when the same quantity of electricity is passed through different electrolytes, the relative number of moles of the elements deposited are inversely proportional to the charges on the ions of the elements.

From this law, it can be seen that the higher the charge, the lower the number of moles of a given element deposited.

Number of moles of aluminium in 9 g of aluminium = mass / molar mass

Molar mass of aluminium = 27 g

Number of moles of aluminium = 9/27 = 1/3 moles

Charge on aluminium ion = +3

3 moles of electrons will discharge 1 mole of aluminium,

1 mole of electrons will discharge 1/3 moles of aluminium

Number of moles of electrons involved = 1 mole of electrons

Charge on copper ion = +2

1 mole of electrons will discharge 1/2 moles of copper.

Mass of 1/2 moles of copper = number of moles × molar mass of copper

Molar mass of copper = 63.5 g

Mass of copper deposited = 1/2 × 63.5 = 31.75 g

An eraser is an example of —

Group of answer choices

an insulator

a closed circuit

a conductor

an open circuit

Answers

Answer:

Insulator

Explanation:

An eraser can't conduct electricity, which makes it an insulator.

What is the mass of 8.23 x 10^23 atoms of Ag

Answers

Answer:

[tex]\boxed {\boxed {\sf Approximately \ 147 \ g\ Ag}}[/tex]

Explanation:

Convert Atoms to Moles

The first step is to convert atoms to moles. 1 mole of every substance has the same number of particles: 6.022 ×10²³ or Avogadro's Number. The type of particle can be different, in this case it is atoms of silver. Let's create a ratio using this information.

[tex]\frac{6.022*10^{23} \ atoms \ Ag}{1 \ mol \ Ag}[/tex]

We are trying to find the mass of 8.23 ×10²³ silver atoms, so we multiply by that number.

[tex]8.23 *10^{23} \ atoms \ Ag *\frac{6.022*10^{23} \ atoms \ Ag}{1 \ mol \ Ag}[/tex]

Flip the ratio so the atoms of silver cancel. The ratio is equivalent, but places the other value with units "atoms Ag" in the denominator.

[tex]8.23 *10^{23} \ atoms \ Ag *\frac{1 \ mol \ Ag}{6.022*10^{23} \ atoms \ Ag}[/tex]

[tex]8.23 *10^{23} *\frac{1 \ mol \ Ag}{6.022*10^{23} }[/tex]

Condense into one fraction.

[tex]\frac{8.23 *10^{23} }{6.022*10^{23} } \ mol \ Ag[/tex]

[tex]1.366655596 \ mol \ Ag[/tex]

Convert Moles to Grams

The next step is to convert the moles to grams. This uses the molar mass, which is equivalent to the atomic mass on the Periodic Table, but the units are grams per mole.

Ag: 107.868 g/mol

Let's make another ratio using this information.

[tex]\frac {107.868 \ g \ Ag}{1 \ mol \ ag}[/tex]

Multiply by the number of moles we calculated.

[tex]1.366655596 \ mol \ Ag*\frac {107.868 \ g \ Ag}{1 \ mol \ ag}[/tex]

The moles of silver cancel out.

[tex]1.366655596 *\frac {107.868 \ g \ Ag}{1 }[/tex]

[tex]1.366655596 * {107.868 \ g \ Ag}[/tex]

[tex]147.4184058 \ g\ Ag[/tex]

Round

The original measurement of atoms has 3 significant figures, so our answer must have the same. For the number we calculated, that is the ones place.

147.4184058

The 4 in the tenths place tells us to leave the 7 in the ones place.

[tex]147 \ g\ Ag[/tex]

8.23 ×10²³ silver atoms are equal to approximately 147 grams.

PLEASE HELP AND FAST!! How many grams of NH4OH are in 0.125L of a 1.4 M solution of NH4OH?

Answers

Answer:

6.132

Explanation:

distinguish between electron and neutron​

Answers

Answer:

Explanation:

Electrons are a type of subatomic particle with a negative charge

Neutrons are a type of subatomic particle with no charge (they are neutral)

When a reaction is balanced we know that the number of _______ is the same on both sides of the reaction.

Answers

Answer:

Atoms I think

Explanation:

When an equal number of atoms of an element is present on both sides of a chemical equation, the equation is balanced.

The equilibrium constant for the reaction shown below is Kc=0.0091. If the equilibrium concentrations of A and B are 0.031 M and 0.0823 M, respectively, what is the equilibrium concentration of C?

Answers

Answer:

[tex][C]=0.0221M[/tex]

Explanation:

Hello there!

In this case, according to the given chemical reaction at equilibrium:

[tex]3A\rightleftharpoons 3B+2C[/tex]

It is possible for us to set up the equilibrium expression as shown below:

[tex]Kc=\frac{[B]^3[C]^2}{[A]^3}[/tex]

Whereas Kc, [A] and [B] are known as 0.0091, 0.031M and 0.0823M and it is required to calculate [C]; thus, we solve for it as follows:

[tex][C]^2=\frac{[A]^3Kc}{B]^3}[/tex]

[tex][C]=\sqrt{\frac{(0.031)^3*0.0091}{(0.0823)^3}}[/tex]

[tex][C]=0.0221M[/tex]

Best regards!

How does the volume of water change the solubility of sodium chloride in simple words?

Answers

Answer:

When sodium chloride dissolves in water to make a saturated solution there is a 2.5 per cent reduction in volume. ... The solubility of salt does not change much with temperature, so there is little profit in using hot water.

Summer happens in Vermont when the sun's rays hit it less or more directly than any other time of year .

Answers

Answer:

More directly.

Explanation:

Summer happens in Vermont when the sun's rays hit it more directly than any other time of year because this direct angle causes more warm environment. In the winter season, the angle of sun is about 45° due to which the place receives less solar radiation and the environment is cold while on the other hand, in the summer season the angle of the sun is about 90° due to which direct sunlight occurs on the region that causes warm and hot environment.

I NEED THIS ASAP

A truck was carrying a substance in a tank. The molecules of that substance were moving away from each other. The truck parked overnight in a place where energy transferred out of the substance. In the morning, the substance was a gas. How were the molecules moving in the morning? Explain why the molecules were moving that way after energy was transferred out of them.

Answers

Answer:

1. In the morning the molecules were moving away from each other with a smaller speed than when the truck was carrying the substance.

2. The reason is that the molecules contain less average kinetic energy, thus their average speed is lower.

Explanation:

Our model of the state (phases) of the substances describes the molecules of solids as not moving away from each other, they are relatively fixed with respect to each other, just vibrating; the molecules of liquids as free to slide pass each other, which permits they to flow, but not moving away from each other; and the the molecules of the gases as moving away from each other, which is the cause of them occupying the whole space of the container that holds them.

According to that, the substance that the truck was carryng was a gas, because the molecules were moving away from each other.

After parking overnight, where energy transferred out of the substance, in the morning, the substance was a gas. Hence, the molecules were moving away from each other too. This answer the first question.

Since energy was transferred out of the substance, in the morning the temperature of the substance decreased (but no enough to make it a liquid). The average kinetic energy of the gases depends only on the temperature. So, the average kinetic energy of the molecules in the morning was smaller than when the truck was carrying the substance. Since the kinetic energy is proportional to the square of the speed of the molecules, the smaller average kinetic energy means that the average speed of the molecules was smaller too. Hence, in the morning the molecules were moving away from each other with a lower speed than when the truck was carrying the substance.

Average kinetic energy is the average sum of all kinetic energy of all the molecules of gases. Therefore, molecules will move at a lesser speed as average kinetic energy will become small.

What is kinetic energy?

It is a energy which is possess by a moving object. It is very difficult to find the correct value of kinetic energy so we find average kinetic energy. Which is very easy to calculate as compared to calculating kinetic energy. It is not dependent on the type of gases or mass of gases.

Mathematically, the formula for kinetic energy can be given as

K.E=1/2mv²

Where,

m= mass of object

v= velocity of object

Molecules will move at a lesser speed as average kinetic energy will become small.

Therefore, molecules will move at a lesser speed as average kinetic energy will become small.

Learn more about the average kinetic energy, here:

https://brainly.com/question/22174271

#SPJ2

how does salt alter the boiling point and freezing point of water

Answers

Answer:

adding salt is like adding an impurity therefore the boiling point might increase from 100°c to maybe 102°c

If Lead (II) nitrate reacted with iron (III) acetate what would the balanced formula be?

Answers

Answer:

Explanation:

3Pb(ii)(NO3)2 + 2Fe(iii) ( C2H3O2 )3   ===> 3Pb( C2H3O2)2 + 2Fe(NO3)3

I know you have likely been given this as a homework assignment, but in real life I doubt you would be able to see any reaction taking place. The products are likely both soluble and both ionize, so I don't think you will get any kind of reaction taking place.

The equation however is balanced.

Which is the correct result of mitosis and
meiosis?

Answers

B. Two diploid cell (2n) and 4 haploid cell (n). Mitosis for somatic cell but meiosis for gametes

Answer:

[tex]\boxed {\boxed {\sf B. \ 2 \ diploid \ cells \ and \ 4 \ haploid \ cells}}[/tex]

Explanation:

Mitosis is a type of cell division. It occurs in somatic cells, which are basically any cells other than sex cells. A cell replicates the genetic material then undergoes one division to create 2 identical cells, both with a complete set of chromosomes. These are known as diploid cells.

Meiosis is another type of cell division, but it occurs only in sex cells, called gametes. The cell replicates the genetic material and the chromosomes cross over, which creates completely unique cells. The cell divide to create 2 cells, but then they divide again to create 4 cells. They each have half of the chromosomes of a somatic cell, so they are haploid cells

So, mitosis results in 2 diploid cells and meiosis forms 4 haploid cells.

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