Determine el PH y el % de disociación de una solución de ácido débil, sabiendo que se disuelven 20 gramos del ácido (masa molar= 55 grs) en un volumen total de 2100 ml. Ka=1,65 x 10 -8
Answer:
pH = 4.27. Porcentaje de disociación: 0.03%
Explanation:
El pH de un ácido débil, HX, se obtiene haciendo uso de su equilibrio:
HX(aq) ⇄ H⁺(aq) + X⁻(aq)
Donde la constante de equilibrio, Ka, es
Ka = 1.65x10⁻⁸ = [H⁺] [X⁻] / [HX]
Como los iones H⁺ y X⁻ vienen del mismo equilibrio podemos decir:
[H⁺] = [X⁻]
[HX] es:
20g * (1mol/55g) = 0.3636moles / 2.100L = 0.1732M
Reemplazando es Ka:
1.65x10⁻⁸ = [H⁺] [H⁺] / [0.1732M]
2.858x10⁻⁹ = [H⁺]²
5.35x10⁻⁵M = [H⁺]
pH = -log[H⁺]
pH = 4.27El porcentaje de disociacion es [X⁻] / [HX] inicial * 100
Reemplazando
5.35x10⁻⁵M / 0.1732M * 100
0.03%Antara berikut ciri manakah bear tentang cuka?
A. Berasa pahit.
B. Berasa tawar.
C. Nilai pH kurang dari 7
D. Nilai pH ialah 7
Answer:
c. nilai pH kurang dari 7
Explanation:
cuka adalah acid
nilai pH bagi acid adalah
antara 1 hingga 6
what creates an ionic bond?
a: The attraction between neutral ions
b: The checks between similarly charged ions
c: the attraction between oppositely charged ions
d: the attraction between neutral atoms
Answer:c
Explanation: it’s c
a.
Suppose a group of bobcats that normally live and hunt in the tops of mountains, start hunting prey at the base of the
mountain and move into the valley below. Which of the following will most likely happen to the prey in the valley?
Their numbers will soon increase.
b. Their numbers will soon decrease.
C. They will move to the tops of the mountains.
d. They will remain unchanged.
Please select the best answer from the choices provided
Ο Α
OB
C
OD
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Answer:
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What is the oxidation number of Chromium in Cr2O74-?
There are seven oxygen atoms, so the total charge is −2⋅7=−14 . So, two chromium atoms have a total oxidation number of +12 . Since one is not more electronegative than the other, we can divide the number by two to get one chromium's oxidation number. So, a chromium atom here has an oxidation number of +6 .
Hope it helps you I'm from ph❤️
A ball is thrown straight up into the air with a speed of 13 m/s. If the ball has
a mass of 0.25 kg, how high does the ball go? Acceleration due to gravity is g = 9.8 m/s2
A. 9.2 m
B. 8.6 m
C. 10.4 m
D. 9.9 m
Answer:
The total energy, i.e. sum of kinetic and potential energy, is constant.
i.e. E = KE + PE
Initially, PE = 0 and KE = 1/2 mv^2
At maximum height, velocity=0, thus, KE = 0 and PE = mgh
Since, total energy is constant (KE converts to PE when the ball is rising),
therefore, KE = PE
or, 1/2 mv^2 = mgh
or, h = v^2 /2g = 13^2 / (2x9.8) = 8.622 m
Hope this helps.
200 ml of a LiF solution is 5.0M concentration. How many grams of LiF does it have?
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In your OWN words explain how season are formed
Answer: Weather currents change wind tempature and there for change the weather of the seasons.
week 4 learning task 1 science 4th quarter
Answer:
what???
Explanation:
what??????????
can you please solve this
IMK Your answer is option C
24 protons and 29 neutrons
"Para enfriar algo rápidamente se hace una mezcla de hielo con sal o, si tiene precaución, alcohol. El punto de congelación bajará y el hielo se derretirá rápidamente. Pese a aparentar haberse perdido el frío, la mezcla formada estará en realidad a unos cuantos grados bajo cero y será mucho más efectiva para enfriar que los cubos de hielo sólidos". El fenómeno relatado corresponde a una consecuencia de:
La pregunta está incompleta, la pregunta completa es;
"Para enfriar algo rápidamente, haga una mezcla de hielo cd sal o, si
tenga cuidado, alcohol. El punto de congelación bajará y el hielo
derretir rápidamente. A pesar de parecer haber perdido el frío, la mezcla
formado será en realidad unos pocos grados bajo cero y será
mucho más eficaz para enfriar que los cubitos de hielo sólido. "La
fenómeno reportado corresponde a una consecuencia de: *
una. Aumento del punto de ebullición
B. disminución de la presión de vapor
C. aumento de la presión de vapor
D. disminución del punto de congelación
Answer:
D
Explanation:
Esta pregunta recuerda las propiedades coligativas. Las propiedades coligativas son propiedades de sustancias que dependen de la cantidad de sustancia presente.
El punto de congelación es una propiedad coligativa. Se sabe que la presencia de impurezas reduce el punto de fusión y congelación. Esto se llama depresión del punto de congelación.
Por lo tanto, la observación registrada en la pregunta es el resultado de la disminución del punto de congelación.
An opening volumetric cylinder filled with water at volume 0.003m after period of
time the water in the cylinder is just evaporated what is the work done by this process?
Answer:
= - 303.975 Joules
Explanation:
Given that:
The volume of the cylinder = 0.003 m^3
Now, to liters:
The volume = 0.003 *1000 L
= 3 L
For an open cylinder, we mean the atmospheric pressure is at standard condition.
Thus, the workdone = -PΔV
= - 1 atm (3 L)
= - 3 L atm
1 L atm to Joules
= 101.325 Joules
Therefore;
=- 3* 101.325 Joules
= - 303.975 Joules
Suggest two reactants to prepare sodium nitrate by titration
Answer:
HNO3 and NaOH
Explanation:
A neutralization reaction is a reaction that occurs between an acid and a base to form salt and water only.
Neutralization reactions are commonly carried out by method of titration. That is, a measured volume of acid of unknown concentration is made to react with a known volume of standard base solution or vice versa.
Two reactants that could be titrated to obtain sodium nitrate are nitric acid and sodium hydroxide.
The reaction equation is as follows;
HNO3(aq) + NaOH(aq) ----> NaNO3(aq) + H2O
The fur on an arctic polar bear appears white all year. The color of the fur is an example of
O A. an organism exchanging materials with its environment
B. an adaptation helping an organism to survive
C. an organism responding to internal stimuli
o D. metabolism regulating an organism's activities
Answer:
It would be B!
Explanation:
Since white fur is a form of camouflage, B would be the correct answer.
Select the correct answer.
Which atom or lon is the largest?
Answer:urenium
Explanation: because his atomic number is 235
Answer:
We know when the no of protons (+ charge) is greater than the no of electrons (- charge), the nucleus pulls the electrons with greater force, hence making the size smaller. Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
K has 19 protons, 19 electrons
K+ has 19 protons, 18 electrons
Ca has 20 protons, 20 electrons
Ca2+ has 20 protons, 18 electrons
Li has 3 protons, 3 electrons
Clearly, the cations are smaller than the atoms, this largest atom/ion will be Ca.
Explanation:
what is the purpose of environmental regulations on chemicals
Answer: EPA regulates the production and distribution of commercial and industrial chemicals, in order to ensure that chemicals for sale and use in the United States do not harm human health or the environment.
Explanation:
PLEASE HELP THIS IS AN EMERGENCY!!!!
A template of a Venn diagram representing common and differentiating characteristics of covalent and ionic bonds is shown.
Which of the following characteristics can be written only in space A? (5 points)
A.)Formed between atoms of similar electronegativities
B.)Formed between two metal atoms mostly found on the left of the periodic table
C.)Formed between two non-metal atoms mostly found on the right of the periodic table
D.)Formed between an atom that tends to lose electrons and an atom that tends to gain electrons
Answer:
D
Explanation:
Ionic bonds form when a metal and a nonmetal exchange electrons.
A) atoms with relatively similar electronegativities share electrons between them and form covalent bonds
B) the force that holds atoms together in a metallic substance is known as a metallic bond. such a solid consists of closely packed atoms....in short, the valence electrons in metals, unlike those of covalent bonds, are nonlocalized and capable of wandering relatively freely throughout the entire molecule
C) bonds formed between two nonmetals are mainly covalent bonds
.The characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
Ionic bondIonic or electrovalent bonds are bonds formed between oppositely charged ions which are formed by a gain or loss of electrons and these ions are held together by strong electrostatic forces of attraction.
Properties of Ionic bondsThey are formed between oppositely charged ions ionsThey occur as a result of electrostatic forces of attraction between oppositely charged ions They are formed between an atom that tends to lose electrons {usually metals} and an atom that tends to gain electrons {usually non-metals}.Therefore, characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
Learn more about ionic bonds at: https://brainly.com/question/13526463
Explain and describe how the photoelectric effect occurs on an atomic level in terms of protons, neutrons, and electrons
Answer:
The photoelectric effect is the emission of electrons when electromagnetic radiation, such as light, hits a material. Electrons emitted in this manner are called photoelectrons.
Based on the wave model of light, physicists predicted that increasing light amplitude would increase the kinetic energy of emitted photoelectrons, while increasing the frequency would increase measured current.
Example of fundamental units?
Answer:
are the units of the fundamental quantities, as defined by the International System of Units
Explanation:
because
'Synthetic detergents are better than soaps'. Justify this statement
Answer:
Synthetic detergents can be used for washing purposes even when the water is hard, whereas soaps are not suitable for washing with hard water. This is because of the fact that synthetic detergents can lather with hard water. Hence, Synthetic detergents better than soaps.
Synthetic detergents work on both soft and hard water, while soap works only with soft water.
Use the table to answer the question
Calculate the average atomic mass of magnesium
A. 24.984 AMU
B. 24.305 AMU
C. 23.985 AMU
D. 25.982 AMU
Answer:
B
Explanation:
hope the picture helps you to understand:)
5 grams of iron react with 5 grams of oxygen to produce iron 3 oxide. If I produce 5 grams of product what is my percent yield?
Answer:
5 grams of iron react with 5 grams of oxygen to produce iron 3 oxide.
The actual yield of the reaction is--- 5 grams.
What is the percent yield?
Explanation:
The balanced chemical equation of the reaction is:
[tex]4Fe(s)+3O_{2} (g)->2Fe_{2} O_3(s)[/tex]
1)Identify the limiting reagent.
2)Using the limiting reagent calculate the amount of theoretical yield formed.
Identification of limiting reagent:
4 mol of Fe reacts with 3mol. of O2
that is:
4mol(55.84g/mol) of Fe reacts with ---- 3mol (32.0g/mol)
=223.36g of Fe reacts with ---- 96g. of O2
then,
5g of Fe requires how many grams of O2?
[tex]=>5g. of Fe * \frac{96g O2}{223.36g Fe} \\=2.14g. of O_{2} .\\[/tex]
But provided 5g of O2.
So, O2 is present more than required.
Hence, O2 is the excess reagent and the limiting reagent is Fe.
The amount of product formed depends only on the amount of Fe only.
Theoretical yield:
From the balanced chemical equation:
4mol. of Fe forms ----- 2mol. of Fe2O3.
that is
223.36g of Fe forms --- 2(159.68g)of Fe2O3.
=>223.36g of Fe forms --- 319.36g of Fe2O3.
then,
5g of Fe forms ----? grams of Fe2O3
[tex]=>5g of Fe * \frac{319.36g Fe2O3}{223.36g of Fe} \\=7.14g. of Fe2O3\\[/tex]
[tex]%Error =\frac{actual yield}{theoretical yield} * 100\\\\ %error=\frac{5g}{7.14g} * 100\\ %error =70.0[/tex]% error=actual yield/ theoretical yield x 100
%error=5g./7.14g x100
=>%error=70.0
Hence, the answer is 70.0%.
What similarities are there between Beta Radiation and Alpha Radiation
The largest particle, Alpha, has the least penetrative power. Positive charge is carried by alpha particles. Two neutrons and two protons are bound together to form an alpha particle. The helium-4 nucleus was later identified as the alpha particle. Among the three types of radioactive emissions, alpha particles have the most mass. An alpha particle has approximately 8000 times the mass of a beta particle. The penetrative power of an alpha particle is reduced due to its large size.
Beta particles are negative-charged high-energy electrons or positrons. Beta particles have a higher penetrative power than alpha particles due to their smaller size.
Hope this helps and if it does, don't be afraid to give my answer a "Thanks" and maybe a Brainliest if it's correct?
which compounds are an alkanes, CnH2n+2? pls reply fast!
Answer:
Methane
Explanation:
Alkanes have the molecular formula of "CnH2n+2" which means for every carbon molecule there are two hydrogens plus two more. For example when there is one Carbon there are four hydrogens, this molecule is known as "Methane"
1. The science that deals with heredity and the factors affecting the transmission of the characteristics is
2. The trait that is usually hidden and will just come out on the second generation is
3. The appearance of the offspring is referred to as
4. The genetic make-up of the genes of the offspring is
5. Having two identical alleles of a particular gene or genes is called
6. The father of Science of Genetic is
7. It is the trait that is being expressed in an organism.
8. The extent to which something is probable is
9. The offspring of two plants/animals of different species or varieties is called
10. It is the number of times that the genotype would appear in an offspring after a test cross is
11. The relative number of offspring manifesting a particular trait or a combination of traits.
12. Having two different alleles of a particular gene or genes is
Answer:
1-Genetics
2-Alleles
3-Organism's genotype
4-Phenotypes and Genotypes
5-Allele
6-Gregor Mendel
7-Genotype
8-Probability
9-Hybrid
10-Genotypic Ratio
11-Phenotypic ratio
12-Heterozygous
Explanation:
Two billiard balls having masses of 0.2 kg and 0.15kg approach each other. The first ball having a velocity of 2m/s hit the second ball which is at rest. What will be the velocity of the first ball if the second ball travels at 1.5 m/s after collision?
Answer: The velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.
Explanation:
Given: [tex]m_{1}[/tex] = 0.2 kg, [tex]m_{2}[/tex] = 0.15 kg
[tex]v_{1}[/tex] = 2 m/s, [tex]v_{2}[/tex] = 0 m/s, [tex]v'_{1}[/tex] = ?, [tex]v'_{2}[/tex] = 1.5 m/s
Formula used is as follows.
[tex]m_{1}v_{1} + m_{2}v_{2} = m_{1}v'_{1} + m_{2}v'_{2}[/tex]
where,
v = velocity before collision
v' = velocity after collision
Substitute the values into above formula as follows.
[tex]m_{1}v_{1} + m_{2}v_{2} = m_{1}v'_{1} + m_{2}v'_{2}\\0.2 kg \times 2 m/s + 0.15 kg \times 0 m/s = 0.2 kg \times v'_{1} + 0.15 kg \times 1.5 m/s\\0.4 kg m/s + 0 = 0.2v'_{1} + 0.225 kg m/s\\0.2v'_{1} kg = 0.175 kg m/s\\v'_{1} = \frac{0.175 kg m/s}{0.2 kg}\\= 0.875 m/s[/tex]
Thus, we can conclude that the velocity of the first ball is 0.875 m/s if the second ball travels at 1.5 m/s after collision.
You have seen that in most of the packed foodstuff,an expiry date is usually printed.If we use that food-stuff after the expiry date,it gives a bad smell and a bad taste. i) Why does the food give a bad taste and bad smell after the expiry date ii) Write any two methods used by the food industry to prolong the life of packed food.
Explanation:
For (i):The oxidation reaction is defined as the reaction where the gain of oxygen atoms or the loss of hydrogen atoms takes place.
Foodstuff tastes bad and releases A bad odour due to the oxidation of food items and this process is called rancidity.
For (ii):To prevent food from getting rancid, various processes can be used:
Using airtight containers to avoid contact with oxygenUsing anti-oxidation to avoid oxidationInserting nitrogen gas into the packaged food items
Why do ionic compounds have higher electrical conductivity than molecular compounds?
support your answer with an example.
Answer:
Ionic compounds are formed from strong electrostatic interactions between ions, which result in higher melting points and electrical conductivity compared to covalent compounds. Covalent compounds have bonds where electrons are shared between atoms.
A gas has a volume of 1000.0 mL at a temperature of 20.OK and a pressure
of 1.0 atm. What will be the new volume when the temperature is changed
to 40.0K and the pressure is changed to
0.5 atm?
Answer:
4000mL
Explanation:
Using the combined gas law equation;
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (mL)
V2 = final volume (mL)
T1 = initial temperature (K)
T2 = final temperature (K)
According to the information given in this question:
V1 = 1000mL
T1 = 20K
P1 = 1.0atm
V2 = ?
P2 = 0.5atm
T2 = 40K
Using P1V1/T1 = P2V2/T2
1 × 1000/20 = 0.5 × V2/40
1000/20 = 0.5V2/40
50 = 0.5V2/40
50 × 40 = 0.5V2
2000 = 0.5V2
V2 = 2000/0.5
V2 = 4000mL