Answer:
Dissociated state is the predominant one
Explanation:
When a molecule with pKa of 4.52 is in an aqueous solution at pH = 4.0, follows the H-H equation, thus:
pH = pKa + log₁₀ [A⁻] / [HA]
Where [A⁻] is the dissociated state and [HA] represents the protonated state
Replacing:
4.0 = 5.2 + log₁₀ [A⁻] / [HA]
-1.2 = log₁₀ [A⁻] / [HA]
0.063 = [A⁻] / [HA]
[HA] = 16 [A⁻]
That means you have 16 times more [HA] than [A⁻] and the dissociated state is the predominant one
The temperature of a 350. mL sample of gas increases from 27 °C to 227 °C. What is the final volume of the sample of gas, if the pressure and amount of gas in the container is kept constant?
Group of answer choices
Answer:
[tex]V_2=583.3mL[/tex]
Explanation:
Hello,
In this case, for the given constant amount and pressure of the, we apply the Charles' law which allows us to understand the volume-pressure behavior as a directly proportional relationship:
[tex]\frac{V_1}{T_1} =\frac{V_2}{T_2}[/tex]
Thus, since we need to compute the volume after the temperature increase (which must be expressed in absolute Kelvins), we obtain V2 as:
[tex]V_2=\frac{V_1T_2}{T_1} =\frac{350.0mL*(227+273.15)K}{(27+273.15)K}\\ \\V_2=583.3mL[/tex]
Best regards.
The Earth's mantle is
A.
hotter than the crust but cooler than the core.
B.
hotter than both the crust and the core.
C.
cooler than both the crust and the core.
D.
cooler than the crust but hotter than the core.
Answer:
C. cooler than both the crust and the core
Explanation:
It is observed that at the mantle, temperatures range from estimatedly 200 °C (392 °F) around the upper boundary with the crust to approximately 4,000 °C (7,230 °F) at the core-mantle boundary.
So we can say the mantle is cooler than both the crust and the core.
What is the hydrogen ion concentration [H+] of a HCl solution if the pH is measured to be 2.0?
Answer:
.01
Explanation:
H30+=10^-pH
- Hope that helps! Please let me know if you need further explanation.
Please help! BRAINLIEST to correct answer!!!!
Answer:
Exothermic ProcessExplanation:
Porosities can have merits and demerits during manufacturing procedures of dental materials. Clarify this statement.
Answer:
The porosities in dental materials can be of merit and not merit since some dental materials need to be porous in order to reduce their weight and improve their properties and functions, whereas in those (which are the majority) porosities are not Merit, see the properties of the material, the function and can even influence dental rehabilitation.
An example of this is the use of vitreous ionomers, which is a dental material, where when it is spatulated it remains porous, it can give recurrence of infectious caries, since its permeability increases, the best cariogenic microorganisms are filtered and porosity works as a retentive site for these microorganisms that make up the dental biofilm.
In summary, the world of dental materials is very wide, some are resins, other cements, others have metallic claims, etc. To say that the presence of porosity is merit or demerit would be ideal because for some materials this is favorable and for others unfavorable since they are very versatile, with different qualities, different degrees of porosity, different molecules, different coefficients of thermal expansion, some do not set, others do not, some are light-cured, others do not, some withstand more mechanical forces and have more elastic modulus and less porosity, while others do not, and thus with many more variables.
Explanation:
In the manufacture of dental materials, much attention is always paid to what the manufacturer indicates in these indications that come on the reverse side of the material or on a paper inside the material container.
This is important to know, because the manufacturer is the one that indicates the mode of use and working time according to the trademark and the chemical composition of the dental material.
That a dental material in its manufacture is more or less porous, makes its density, weight and volume possibly be affected, there are materials that seek to increase porosity for a certain purpose, while others seek the opposite, depending on the function that is applied, will have more or less pores.
The example we gave above about the vitreous ionomer is an example that indicates that in the case of restorative dental materials where the function is to SEAL the porosity is almost nil, since otherwise it will not seal the cavity that was formed with caries and not the infectious problem would be solved.
On the other hand, in the surgical field of dentistry there are bone grafts or porous macroparticles that are for the purpose of bone replacement, which in order to be integrated need blood vessels that run over these pores, irrigating the area of bone neoformation well, in this case the merit of porosity if necessary and it is essential that they be very porous.
4. A burning candle is an example of a chemical reaction taking place. What i
can be inferred about this reaction? Choose the correct answer."
A.Mass is not conserved.
B. The reaction absorbs energy. C.The reaction releases energy
D.There are reactants but no products,
Answer:
C
Explanation:
heat is energy
What is the concentration of a solution in which 0.99 g of KOH are dissolved in 500 mL?
Answer:
.00352mol/L
Explanation:
molarity (concentration) = number of moles / volume of solvent (in L)
M = .99g / 56.108g/mol / .5L
M = .0176mol / .5L
M = .00352mol/L
Using Boyle's Law solve the following: An unknown gas has a volume of 200.0 mL and a pressure of 350.0 torr, pressure were increased to 700.0 torr, what is the resulting volume?
Answer:
400 mL
Explanation:
Boyle's Law: [tex]P_1*V_1 = P_2*V_2[/tex]
Let x = the resulting volume
350 (200) = 700 (x)
x = 400 mL
If an insufficient amount of liquid unknown had been used, how would this have effected the value of the experimental molar mass
Answer:
Actual yield reduces the more.
Explanation:
An actual yield of the course of a chemical reaction is the mass of a product actually obtained from the reaction.
In practice you see it and It is usually less than the theoretical yield.
Various reasons may come up to explain this away but here is one:
• incomplete reactions, simply put here some of the reactants do not react to form the product.
The same applies in the question about the actual yield will reduce significantly in molar mass now that insufficient amount of reagent are used.
What is the ideal pH level for your blood?
Lewisite (2-chloroethenyldichloroarsine) was once manufactured as a chemical weapon, acting as a lung irritant and a blistering agent. During World War II, British biochemists developed an antidote which came to be known as British anti-Lewisite (BAL) (2,3-disulfanylpropan-1-ol). Today, BAL is used medically to treat toxic metal poisoning. Complete the reaction between Lewisite and BAL by giving the structure of the organic product and indicating the coefficient for the number of moles of HCl produced in the reaction.
Answer:
2 HCl
Explanation:
Please kindly check attachment for the step by step solution of the given problem.
Considering the limiting reactant, what is the mass of zinc sulfide produced from 0.250 g of zinc and 0.750 g of sulfur? Zn(s)+S(S) ZnS(s)
Answer:
The mass of zinc sulfide produced is [tex]M_{ZnS} = 0.76 \ g[/tex]
Explanation:
From the question we are told that
The mass of zinc is [tex]m_z = 0.750 \ g[/tex]
The mass of sulfur is [tex]m_s = 0.250 \ g[/tex]
The molar mass of [tex]Zn_{(s)}[/tex] is a constant with value 65.39 g /mol
The molar mass of [tex]S_{(s)}[/tex] is a constant with value 32.01 g/mol
The molar mass of [tex]ZnS_{(s)}[/tex] is a constant with value 97.46 g/mol
The reaction is
[tex]Zn_{(s)} + S_{(s)} ------> ZnS_{(s)}[/tex]
So from the reaction
1 mole of [tex]Zn_{(s)}[/tex] react with 1 mole of [tex]S_{(s)}[/tex] to produce 1 mole of [tex]ZnS_{(s)}[/tex]
This implies that
65.39 g /mol of [tex]Zn_{(s)}[/tex] react with 32.01 g/mol of [tex]S_{(s)}[/tex] to produce 97.46 g/mol of [tex]ZnS_{(s)}[/tex]
From the values given we can deduce that the limiting reactant is sulfur cause of the smaller mass
So
0.250 g of [tex]Zn_{(s)}[/tex] react with 0.250 of [tex]S_{(s)}[/tex] to produce [tex]x \ g[/tex] of [tex]ZnS_{(s)}[/tex]
So
[tex]x = \frac{97.46 * 0.250}{32.01}[/tex]
[tex]x = 0.76 \ g[/tex]
Thus the mass of the mass of zinc sulfide produced is
[tex]M_{ZnS} = 0.76 \ g[/tex]
CH³C⁴HCOCH³ how many atoms of each element are in one molecule of 2-heptanone
Answer:
- 7 carbon atoms.
- 14 hydrogen atoms.
- 1 oxygen atom.
Explanation:
Hello,
In this case, for the given compound, heptanone, whose chemical formula is:
[tex]CH_3COCH_2CH_2CH_2CH_2CH_3[/tex]
We can write the molecular formula showing the present atoms of each element:
[tex]C_7H_{14}O[/tex]
In such a way we have:
- 7 carbon atoms.
- 14 hydrogen atoms.
- 1 oxygen atom.
Best regards.
A sample of gas at occupies 10m3 at a pressure of 120 kPa. If the volume of the sample is changed to 3m3, what is the new pressure of the gas?
Answer:
400 kPa
Explanation:
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
Answer:
400 kPa
The answer is right since its from ck12
How is a niche different than a habitat?
A habitat is more than a physical place; it's a species' role in a specific place and it can change from niche to niche.
A niche is more than a physical place; it's a species' role in a specific place and it can change from habitat to habitat.
A niche and a habitat are the same.
A niche is just a physical place; a habitat is a species' role in a specific place.
Answer:
A niche is more than a physical place; it's a species' role in a specific place and it can change from habitat to habitat.
Explanation:
Niche: In biology, the term "niche" is described as a process through which different organisms tends to fit-in into a specific ecosystem or an ecological community. However, a niche is considered as the "evolutionary result" of a specific species behavioral, morphological, and physiological adaptations associated with its surroundings.
Habitat: In biology, the term "habitat" is described as an environmental or ecological area that is being inhabited by a specific species of plants, animals, or other organisms.
Therefore, a niche is entirely different from a habitat because an organism's niche tends to explain every different aspect of its life whereas its habitat explains the place it lives.
What is the concentration of a solution if 0.450 mol of NaCl dissolved in 750 mL of water?
Answer:
.6mol/L
Explanation:
molarity = number of moles / volume of solvent (in L)
750mL / 1000mL/L = .75L
M = .450mol / .75L
M = .6mol/L
2. What happens to the pH when you add more H+ ions to a solution that has no buffers?
How many kilograms of solvent (water) must 0.71 moles of KI be dissolved in to produce a 1.93 m solution?
Answer: kg= 0.37
Explanation:
Use the molality formula.
M= m/kg
How many grams do 4.8 x 1026 atoms of silicon
weigh?
Answer in units of g.
2. What are the similarities between law of triads and law of octaves?
Answer:
The similarities are the groups, triads law is a law where they are in groups or three, the octaves law is the 'best' law, is the one who every atom wants, they do everything to be in groups of eight.
Explanation:
Which statements describe inorganic compounds? Check all that apply
Inorganic compounds contain carbon
Inorganic compounds usually lack carbon
Inorganic compounds are not associated with or made from living things,
Inorganic compounds include fruits and vegetables,
Inorganic compounds include salt and water
Answer:
b, c, e
Explanation:
Inorganic compounds usually lack carbon.
Inorganic compounds are not associated with or made from living things.
Inorganic compounds include salt and water.
Answer:
yes the answer id bce
Explanation:
Which of the following will increase the boiling point of water?
Adding more water
Adding sugar
Removing some of the water
None of the above
Answer:
Explanation:
Adding sugar
Prepare a flow diagram for extraction of 2-chlorobenzoic acid and 1,4-dichlorobenzene.
Answer:
See explanation below
Explanation:
To do aflow diagram for extraction of these two components of a sample, we need to analize both reagents so we can make a great diagram and separate both reagents.
First, let's see the acid. The 2-chlorobenzoic acid is a relativel strong acid, so, in order to separate this from a sample we need to use a base to do so. However, it's very important the use of the base here, we cannot use any base to do it, for the main reason that the sample has other component, and this component may react too with the base and the separation will not be succesfull. So, as the chlorobenzoic acid is a relatively strong acid, if we use a strong base such as NaOH, this will react with the acid, but it will also react with the 1,4-dichlorobenzene forming a Sn2 product and a salt like this.
C₆H₄Cl₂ + NaOH ---------> C₆H₅OCl + NaCl
This is the reason which we cannot use NaOH, because it's a strong base that may react with other compounds in the sample.
To solve this, we can use a weak base such as NaHCO₃. This weak base has the strength enough to react with the benzoic acid, but not strong enough to react with the dichlorobenzene.
So, the first step is dissolve the sample in an organic solvent like ether. The next step is mixing the sample with NaHCO₃. This will cause the layer to divide into two layers. One aqueous layer that will have the product of the acid with the base, and an organic layer with the dichlobenzene. Afterward, we just need to use a strong acid like HCl, but dilluted in the aqueous layer to regenerate the acid, and in the organic layer, just heat the solution til the whole solvent evaporates completely.
The flow diagram is below in the attached picture.
Describe an autopsy table
After the body is cleaned, the body is weighed and measured before being placed on the autopsy table for reexamination. The autopsy table is typically a slanted, aluminum table with raised edges that has several faucets and drains used to wash away collecting blood during the internal investigation.
Answer:
A table used to scientifically determine the cause of death of a human or animal
Explanation:
A chemist wants to increase the solubility of a solid in water. Which of the
following will NOT help? *
-increase the temperature
-decrease the particle size
-Increase stirring
-increase pressure
Answer:
- Increase pressure .
Explanation:
Hello,
In this case, during the dissolution process, the solute's molecules rearrange in order to get together with the solvent's molecules, in this case water.
Now, since we are talking about a solid whose particles are intimately held together, the only way to separate them is by increasing the temperature because the molecules start moving so they can join water's molecules, decreasing particle size since they will be more likely to separate to each other and increasing stirring since the applied energy will break the solid's intramolecular forces.
In such a way, since pressure significantly affects gases and slightly affects liquid, it is not able to modify a solid, just extreme pressures such as it needed to produce diamonds, is able to affect a solid. For that reason, increasing the pressure will not increase the solid's solubility.
Best regards.
the diagram above represents a reflex arc in a human. This pathway responds when someone touches something that causes pain, such as a hot stove. Which of the following shows the correct order of the body systems involved in this response?
A) Integumentary, respiratory, digestive
B) Circulatory, respiratory, nervous
C) Integumentary, nervous, muscular
D) Circulatory, digestive, nervous
Answer:
C) Integumentary, nervous, muscular
Explanation:
When a human body touches a hot stove , our sense organ which is integumen first of all receives the impulse of heat . The impulse is transformed into electrical signal which is transmitted to brain which is a part of nervous system . Then brain processes it and command signal is sent to muscle of hand to move it away from that place . Hence the order is
Integumentary, nervous, muscular .
A crystal of table salt (NaCl) is dissolved in water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?
A crystal of table salt (NaCl) is dissolved in water. Which of the following statements explains why the dissolved salt does not recrystallize as long as the temperature and the amount of water stay constant?
Na+ and Cl- ions lose their charges in the water.
Water molecules surround the Na+ and Cl- ions.
Na+ and Cl- ions leave the water through vaporization.
Water molecules chemically react with the Na+ and Cl- ions.
Your answer: -
Answer: B - Water molecules surround the Na+ and Cl- ions.
A child shivers in a cold rain but does not feel cold, what is the biochemistry behind it
Due to prokaryote
Explanation:
Which picture shows how the moon from earth when it’s in the position
Explanation:
This picture shows how the moon from earth when it is in position
Why did the Mt. Pinatubo eruption result in global temperatures dropping almost two degrees?
Answer:
In the case of Mount Pinatubo, the result was a measurable cooling of the Earth's surface for a period of almost two years. Because they scatter and absorb incoming sunlight, aerosol particles exert a cooling effect on the Earth's surface.
Explanation:
Temperature measures the average kinetic energy of particles of the substances. Therefore, the Mt. Pinatubo eruption result in global temperatures dropping almost two degrees.
What is temperature?Temperature is used to measure degree or intensity of heat of a particular substance. Temperature is measured by an instrument called thermometer.
Temperature can be measured in degree Celsius °c, Kelvin k or in Fahrenheit. Temperature is a physical quantity. Heat always flow from higher temperature source to lower temperature source.
We can convert these units of temperature into one another. The relationship between degree Celsius and Fahrenheit can be expressed as:
°C={5(°F-32)}÷9
The Mt. Pinatubo eruption result in global temperatures dropping almost two degrees because they scatter and absorb incoming sunlight, aerosol particles exert a cooling effect on the Earth's temperature.
Therefore, the Mt. Pinatubo eruption result in global temperatures dropping almost two degrees.
To know more about temperature, here:
https://brainly.com/question/13694966
#SPJ6
