Answer:
mirar respuesta abajo
Explanation:
Muy bien. Antes de responder lo que piden en el problema, vamos a calcular la concentración inicial de la solución A:
1) Concentración de la solución A:
En este caso, se sabe que se usaron 3,5 g de la sal, se puede calcular los moles usando el peso molecular y la masa:
n = m/PM (1)
Aplicando tenemos:
n = 3,5 / 98 = 0,0357 moles
Conociendo los moles, podemos calcular la concentración:
M = n/V (2)
Aplicando la formula tenemos:
M = 0.0357 / 0.200 = 0.1785 M
Esta es la concentración del ácido etiquetado como "Solución A".
Ahora podemos ver la concentración de la solución B, para luego calcular las concentraciones molares de los iones en solución y sus respectivos pH.
2) Concentración del ácido en la solución B:
Con la concentración de "A", se puede determinar la concentración de la solución B. Aqui podemos esperar que sea un valor mas bajo, puesto que es una dilución la que estamos haciendo. Por lo tanto.
Si se toma 5.5 mL de la solución A, entonces:
n = 0.1785 * 0.0055 = 0.00098 moles
Con esto, se calcula la nueva concentración:
M = 0.00098 / 0.070 = 0.014 M
Esta es la concentración de la solución B. Ahora para calcular pH y concentraciones de los iones en equilibrio, hay que plantear la reacción acido base en equilibrio. Como es el mismo compuesto, usaremos la misma ecuación.
3) pH de las soluciones A y B:
Planteamos la reacción de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb
Calculando el Kb, sería asi:
Kb = Kw/Ka
Kb = 1x10⁻¹⁴ / 1.8x10⁻⁵ = 5.56x10⁻¹⁰
Ahora reescribimos la ecuación y hacemos una tabla de equilibrio:
CH₃COO⁻ + H₂O <------> CH₃COOH + OH⁻ Kb = 5.56x10⁻¹⁰
i) 0.1785 x x
eq) 0.1785-x x x
Kb = [OH⁻] [CH₃COOH] / [CH₃COO⁻]
Reemplazando nos queda:
5.56 * 10⁻¹⁰ = x² / (0.1785-x)
Y como Kb es muy pequeño, se asume que el valor de x será también pequeño, asi que podemos redondear la resta a simplemente 0.1785, quedando tan solo:
5.56 * 10⁻¹⁰ = x² / (0.1785)
x² = 5.56*10⁻¹⁰ * 0.1785
x = √9.9246*10⁻¹¹
x = 9.96*10⁻⁶ M
Esta es la concentración de [OH⁻] y [CH₃COO⁻] en la solución A.
Aplicando lo mismo para la solución B (Cambiando solo el dato de concentración) nos queda:
x = √5.56*10⁻¹⁰ * 0.014
x = 2.79x10⁻⁶ M = [OH⁻] = [CH₃COO⁻]Finalmente, para calcular pH, se calcula primero el pOH y luego el pH:
pH = 14 - pOH
pOH = -log[OH⁻]
Para la solución A:
pOH = -log(9.96*10⁻⁶) = 5
pH = 14 - 5
pH = 9En el caso de la solución B:
pOH = -log(2.79*10⁻⁶) = 5.55
pH = 14 - 5.55
pH = 8.45Espero te ayude
Volcanic belts form along
a.
islands in the Pacific Ocean.
b.
North American mountain ranges.
c.
the boundaries of Earth’s plates.
d.
the coast of Antarctica.
Please select the best answer from the choices provided
1 pc
Calculate the volume of a an object that has a height of 14.3cm, length or
25.2cm, width of 6.7cm. *
46.2cm
2414.412 cm
0.085 cm
53.785 cm
Answer:0.085
Explanation:
Which change would increase the pressure exerted by a gas?
removing gas molecules from the container
transferring the gas to a larger container
raising the temperature of the gas
reducing the force of the molecules hitting the container
Answer:
C - raising the temperature of a gas
Explanation:
as you raise temperature, kinetic energy rises, and so does pressure
Answer:
C.
raising the temperature of the gas
Explanation:
Edg. 2020
Other guy is right i got 100%
Is this actually right
Answer:
what?????????i don't see a question
Answer:
Yes
Explanation:
Which of the following best describes how Thomson
concluded that electrons are present in all atoms.
a
The charge-to-mass ratio of electrons is always the
same constant, no matter which substances are
used in the cathode ray tube.
b The cathode ray was able to turn a wheel.
The cathode ray always bent toward a negatively
charged plate.
d
The charge-to-mass ratio is unique to each different
element.
Answer: A
Explanation:
The charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube.
Explanation:
Thomson in his model of atom discussed that the atom consists of a negative charge particle termed electron randomly distributed in the positively charged sphere to balance the negative charge.His model of the atom was also known as the Plum pudding model of the atom. In which electrons are embedded in positive soup.He discovered electrons by conducting an experiment with cathode rays in which cathode rays emerging from the cathode were observed to be deflected towards the positively charged plate.He also conducted the same experiment with different metals (for anode and cathode) and gases and found out that the charge to mass ratio of the electron was regardless of the metals or gases used in the experiment.With this, he landed on the conclusion that these particles of cathode rays are the universal component of matter.So, from this, we can conclude that the charge-to-mass ratio of electrons is always the same constant, no matter which substances are used in the cathode ray tube describes Thomson's conclusion that electrons are present in all atoms.
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If water does break down by electrolysis to form new substances, what might be formed?
What is the mass of 4.49 x 10º carbon dioxide, CO2, molecules?
What is an atomic theory?
What is an isotope?
How is the atomic mass of an element calculated?
Answer:
Atomic theory is the scientific theory that matter is composed of particles called atoms.
isotopes are variants of a particular chemical element which differ in neutron number, and consequently in nucleon number.
to calculate the atomic mass of a single atom of an element, add up the mass of protons and neutrons.
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thanks babe!
Explanation:
how many elements belong to the Halogen family? list the member element by thier symbol.
Answer: six elements
Explanation: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (As), and tennessine (Ts)
Answer:
there are six elements
How many protons, electrons and neutrons do A nitrogen atom with atomic number 7 and mass number 14
Answer:
p =7
e = 7
n = 7
Explanation:
proton = atom number
electron = atom number - muatan
neutron = mass nimber - atomic number
is ice forming and then melting back into water a physical change
yes it isssss abcdefghijk
Water can undergo a change of state when its energy changes at specific temperatures. Solid water, or ice, changes into liquid water when its energy increases at its melting point. a. Describe this process. b. Explain how the energy changes with each state.
Answer: The solid turns into liquid during melting.
Explanation:
a. The process of a solid turning into liquid is called melting. The solid ice turns into a liquid during the melting process. The solid molecules gain energy and flow as a liquid.
b. The energy of the molecules increases in the liquid state. When the ice turns into a liquid the energy of the molecules increases. The application of heat or excess temperature increases the energy of the molecules.
Which electron configuration represents the electrons in an atom of sulfur in an excited state? 2 – 8 – 6
2 – 7 – 7
2 – 8 – 7
2 – 7 – 8
The relations of the quantum numbers allow to find that the correct answer for the configuration of the excited state is:
2 - 7 - 7
The electronic configuration of the elements is the distribution of electrons and different levels and sublevels fulfilling the relationships between quantum numbers.
The principal quantum number (n) goes from 0 to infinity The orbital quantum number (l) goes from 0 to n-1, in general it is represented by lera s, p, d, f The magnetic quantum number ([tex]m_l[/tex]) ranges from -l to l The spin quantum number ([tex]m_s[/tex]) can have two values + ½ and - ½
In the base configuration Sulfur of the periodic table is 2 - 8 - 6
This is at the lowest energy configuration, when the atom acquires energy, an electron from its shell must be promoted to the next level.
That is, an electron from level n = 2 that is full is promoted to level n = 3 since in this shell there is still room for two electrons, the configuration of the excited state is:
2- 7 - 7
Let's examine the different alternatives:
1) 2 - 8 -6
False, this is the configuration of the base state
2) 2 - 7 - 7
True. An electron is promoted to the next level due to the excitation of the atom
3) 2 - 8 -7
False, in this configuration the atom becomes an ion
4) 2 - 7 - 8
False, there is an electron transfer between two levels, but there is an extra electron that turns that atom into an ion
In conclusion using the relationships of quantum numbers we can find that the correct answer for the excited state configuration is:
2 - 7 - 7Learn more here: brainly.com/question/16762037
Which of the following is true about pure substances? A. A pure substance has the same chemical properties throughout. All pure substances are unable to be separated by any means. c. A pure substance can only be made up of one kind of atom. D. A pure substance can always be separated by physical means.
Answer:first one
Explanation:
A pure substance has same chemical properties throughout , it cannot be separated by any means and it is made up of one kind of atom.
What are chemical properties?
These properties are defined as those properties which become evident during or after a chemical reaction after the identity of the substance is changed during chemical reaction.
These properties cannot be determined externally just by viewing the substance ,these change immensely after a substance undergoes a chemical change.These are used for identification of unknown substances and for building up chemical classifications.
The major chemical properties are flammability,toxicity,reactivity,acidity and heat of combustion.For a chemical property to be apparent , it is necessary that the structure of the substance is altered.
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Where do rivers usually begin?
at the ocean
at groundwater outlets
in mountainous regions
in lakes and larger rivers
Answer:
in mountainous regions
Explanation:
The rivers usually begins in mountainous regions. A river's source is typically located in a high area, such a mountain or a hill. A river may have several sources. Some rivers start where an underground natural spring discharges water.
What is a mountain ?A mountain is an elevated area of the crust of the Earth, typically with steep sides that reveal a substantial amount of bedrock that has been exposed.
Although definitions vary, a mountain is often taller than a hill, rising normally at least 300 meters above the surrounding terrain, and differs from a plateau in having a constrained peak region.
Every river has a beginning place where the water flow starts. We refer to this source as a headwater. Some rivers have their beginnings in hills or mountains, where rainwater or snowmelt gathers and creates little channels.
It is possible for the headwater to originate from mountain snowmelt or rainfall, but it is also possible for it to bubble up from the ground or develop at the edge of a lake or big pond.
Thus, option C is correct.
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32 N of Force. 37 N force. How strong is the net force and in which direction?
how many atoms can you fit on the head of a pin
Answer:
According to google, "About five million million hydrogen atoms could fit. Some factors would affect that number like the area of the head and the size of atoms (as well as attractions between atoms). Some atoms are larger than others." Is this accurate? I'm not sure. Good luck! :)
Which particle is NOT made up of quarks?
A: a proton
B: a neutron
C: an electron
Answer: C: an electron
Explanation:
Answer:
C: electrons
Explanation:
How is a substance’s solubility in another substance determined?
A. Add solvent till no more will dissolve
B. Add solvent stepwise till no more will dissolve
C. Add solute until no more will dissolve in a fixed amount of solvent
D. Cool the solvent
Answer:
b
Explanation:
now explanation because that is answer
This picture shows a model if a cell. What is the main function of the part labeled Z in the model?
Answer:
store water so b
Explanation:
labeled Z in the model refers to store food and other material in the cell.
what is cell?
cell can be defined as the basic unit of the living cell, it can be unicellular or multicellular. unicellular organism are prokaryote and some of the unicellular eukaryotes whereas multicellular organisms are eukaryotes like plants and animals.
a basic component of cell are cell membrane, cytoplasm, nucleus, mitochondria, lysosome, golgi body, endoplasmic reticulum.
cell wall only present in plant cell and prokaryotic cell while it is absent in animal cell, the function of cell wall is to provide protection
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Protons have a __________________ charge and are found in the area of an atom called ________________________.
Answer:
Positive
Nucleus
Explain how you would dilute a 1 mol/dm solution to one-tenth of its original
concentration.
Answer:
13.123.
Explanation:
What metal is Potassium (K)?
Explanation:
Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure
Answer:
alkali metalExplanation:
Potassium is a chemical element with symbol K and atomic number 19. Classified as an alkali metallist the elements symbols for the elements that are designated with neon green
Answer:
h,c,n,o,p those are the elements
why does the moon shine
Answer:
The moon reflects light from the sun making it appear bright in the sky.
Explanation:
Answer: Its a reflection of the sun's light
Explanation: the light from the sun bounces off of the moon
In Ernest Rutherford's gold foil experiments, some alpha particles were deflected from their original paths, but most passed through the foil with no deflection. Which statement about gold atoms is supported by these experimental observations?
Gold atoms consist mostly of empty space.
Gold atoms are similar to alpha particles.
Alpha particles and gold nuclei have opposite charges.
Alpha particles are less dense than gold atoms.
Answer:
A
Explanation:
Which statements about scientific explanations are true?
I. Scientific explanations must prove that a hypothesis is true.
II. Scientific explanations should be based on evidence or data.
III. Scientific explanations must have logical and consistent arguments.
IV. Scientific explanations should use scientific principles, models, and theories.
Answer:
The statement that is true is:
II. Scientific explanations should be based on evidence or data.
~Lylliara Jackson~
You put a drop of food coloring into a container of room temperature water and watched as the color spread out in the water. Describe what caused the color to spread. (You do NOT stir it)
Answer:the dye is heavier than the water so the substances fuse together instead of sitting at the top much like the phenomenon with oil and water combination
Have a good day!
Why are the coefficients before a chemical symbol important?F. They show the number of elements in each molecule.G. They indicate the number of molecules of each substance.H. They describe the number of times each molecule reacts.J. They explain the order in which the reaction takes place
Answer:They indicate the number of molecules of each substance
Explanation:
When we write chemical reaction equations, we usually put a number before the symbol of each reactant.
These coefficient shows the number of molecules of that specie that is involved in the balanced reaction equation for the reaction.
These coefficients are important because they are used in carrying out stoichiometric calculations.
The diagram shows a model of an animal cell. Explain how you'd modify the model to show the structures in a plant cell.
Answer:to show the structures of a plant cell,add a cell wall around the membrane and increase the size of the vaculoe insidethe cell, draw green ovals to represent chloroplasts.
Explanation: