Answer:
c. 100:1.
Explanation:
Hello,
In this case, considering the Henderson-Hasselbach equation:
[tex]pH=pKa+log(\frac{[A^-]}{[HA]} )[/tex]
And the pH two units above the pKa:
[tex]pH=pKa+2[/tex]
We obtain the required ratio as follows:
[tex]pKa+2-pKa=log(\frac{[A^-]}{[HA]} )\\\\\frac{[A^-]}{[HA]} =10^2=100[/tex]
Which is also a c. 100:1 ratio containing 100 parts of base per 1 part of acid.
Regards.
According to Henderson - Hawelbach equation:
[tex]\to pH = pka + \log (\frac{A^{-}}{HA})...........(a)[/tex]
According to question pH two unit above pka:
[tex]\to pH = pka + 2[/tex]
Put value of PH is equation (a)
[tex]\to pKa+2=pKa+ \log (\frac{A^{-}}{HA})\\\\\to 2= \log (\frac{A^{-}}{HA})\\\\\to (\frac{A^{-}}{HA})= 10^2\\\\\to (\frac{A^{-}}{HA})= 100\\\\[/tex]
So, the ratio is [tex][100 : 1][/tex]
Therefore, 100: 1 Ratio containing 100 part of base per 1 part of acid.
Learn more:
brainly.com/question/3934133
What are different types of measurements in chemistry (make sure it's relevant)?
Answer:
Meters, kilograms, kelvin, candela, mole, ampere, seconds.
Explanation:
These are the seven different types of measurements in chemistry. Hope it helps!
A person's heartbeat is 79 beats per minute. If his/her heart beats 3.1e9 times in a lifetime, how long (in whole years) does the person live?
Answer:
75 years
Explanation:
The heart of the person beats 3.1x10⁹ times. As the heartbeat is 79 beat / min. The minutes the person lives are:
3.1x10⁹ beat * (1min / 79beat) = 3.92x10⁷ min.
1 hour are 60 minutes:
3.92x10⁷ min * (1 hour / 60min) = 6.54x10⁵hours
24 hours are 1 day:
6.54x10⁵hours * (1 day / 24h) = 2.725x10⁴ days.
1 year are 365 days:
2.725x10⁴ days * (1 year / 365 days) = 74.6 years.
In whole years are 75 years
What is observational evidence?
Answer:
evidence you see with your eyes
Explanation:
What is impossible for a machine to do?
A. do a greater amount of work than the amount of work done on the machine
B. apply a force in a direction that is different than the direction of the force applied to the machine
C. move an object a greater distance than the distance that part of the machine was moved
D. apply a force that is less than the force that is applied to the machine
Answer:
CExplanation:
move an object a greater distance than the distance that part of the machine was moved
Answer:
a, sorry for late answer!!Explanation:
Identify the structure of (E)-2-butenal
Answer:
See attached picture.
Explanation:
Hello,
In this case, the E-Z nomenclature for alkenes is also related with the trans-cis ones, being the Z (zusammen) same as cis and E (entgegen) same as trans, therefore, for the structure of the (E)-2-butenal which has the double bond at the second carbon is shown on the attached picture considering it is an aldehyde with the carbonyl group due to the -al- suffix.
Regards.
Identify the precautions to take with exits in the lab.
What is a molarity a measurement
Answer:
Molarity indicates the number of moles of solute per liter of solution and is one of the most common units used to measure the concentration of a solution.
Explanation:
Answer:
concentration
Explanation:
QUESTION 10
A bottle of vitamin water contains 3500 mg of potassium in 591.5g of H 20 What is the concentration of potassium by mass percent?
085.5%
O 5.92%
O 0.59%
O 16.9%
Answer:
[tex]\% m/m=0.59\%[/tex]
Explanation:
Hello,
In this case, since the by mass percent is for potassium in this vitamin is:
[tex]\% m/m=\frac{m_K}{m_K+m_W}*100\%[/tex]
Thus, for 3500 mg of potassium that in grams are 3.5, the by mass percent turns out:
[tex]\% m/m=\frac{3.5g}{3.5g+591.5g}*100\%\\\\\% m/m=0.59\%[/tex]
Best regards.
What two physical properties are used to describe matter?
Answer:
(masa, volumen y temperatura), las cuales miden valores que no sirven en sí para identificar una materia de otra, y otras denominadas Propiedades Características.
Explanation:
Explain why hydrogen and oxygen are transported as liquids rather than gases in a shuttle fuel tank
Answer:
Explanation:
Oxygen takes up less space as a liquid than as a gas, so engineers can fit more oxygen into the same tank.
Hope this helps
plz mark as brainliest!!!!!!!
what is the coefficient of O2 when the equation is balanced?C4H8O2+O2
What is the change in density if a sample goes from 3.21 g/L to 5.43 g/mL?
Answer:
[tex]\Delta \rho =2.22 g/mL[/tex]
Explanation:
Hello,
In this case, since a change in science is widely known to be considered as a subtraction between the the final and initial values of two measured variables and is represented via Δ, here the final density is 5.43 g/mL and the initial one was 3.21 g/mL, therefore, the change in density is:
[tex]\Delta \rho=\rho _f-\rho _i\\ \\\Delta \rho=5.43g/mL-3.21g/mL\\\\\Delta \rho =2.22 g/mL[/tex]
Best regards.
Practice entering numbers that include a power of 10 by entering the diameter of a hydrogen atom in its ground state, dH=1.06×10−10m d H = 1.06 × 10 − 10 m , into the answer box.
Answer:
The diameter of the hydrogen [tex]\mathbf{d =1.0605 \times 10^{-10}\ m}[/tex]
Explanation:
From the given information:
Using the concept of Bohr's Model, the equation for the angular momentum can be expressed as:
[tex]L = \dfrac{nh}{2 \pi}[/tex]
Where the generic expression for angular momentum is:
L = mvr.
replacing the value of L into the previous equation, we have:
[tex]mvr= \dfrac{nh}{2 \pi}[/tex]
[tex]v= \dfrac{nh}{2 \pi mr}[/tex] ----- (1)
The electron in the hydrogen atom posses an electrostatic force which gives a centripetal force.
[tex]\dfrac{ke^2}{r^2} = \dfrac{mv^2}{r}[/tex] ----- (2)
replacing the value of v in equation (1) into (2), and taking r as the subject of the formula, we have:
[tex]\dfrac{ke^2}{r} = m (\dfrac{nh}{2 \pi mr})^2[/tex]
[tex]ke^2=\dfrac{n^2h^2}{4 \pi^2 mr}[/tex]
[tex]r =\dfrac{n^2h^2}{4 \pi^2 mke^2}[/tex]
For ground-state n = 1
[tex]h = (6.625 \times 10^{-34} \ J.s)^2[/tex]
[tex]m =( 9.1 \times 10^{-31} \ kg)(9 \times 10^9 \ N .m^2/C^2)[/tex]
[tex]Ke = (1.6 \times 10^{-19} \ C)^2[/tex]
[tex]r =\dfrac{(1)^2(6.625 \times 10^{-34})^2}{4 \pi^2 (9.1 \times 10^{-31} )(9 \times 10^9 ) (1.6 \times 10^{-19})^2}[/tex]
[tex]r =\dfrac{4.3890625 \times 10^{-67}}{8.27720295 \times 10^{-57}}[/tex]
[tex]\mathbf{r = 5.3025 \times 10^{-11} \ m}[/tex]
Therefore, the diameter of hydrogen d = 2r
[tex]\mathbf{d = ( 2 \times 5.3025 \times 10^{-11} \ m})}[/tex]
[tex]\mathbf{d =1.0605 \times 10^{-10}\ m}}[/tex]
Which best explains why the trend in noble gas boiling points increases down the group?A) increasing dispersion interactions B) increasing dipole-dipole interactions C) increasing ion-dipole interactions D) increasing hydrogen bonding interactions E) increasing ion-ion interactions
Answer:
A) increasing dispersion interactions
Explanation:
Polarizability allows gases containing atoms or nonpolar molecules (for example, to condense. In these gases, the most important kind of interaction produces dispersion forces, attractive forces that arise as a result of temporary dipoles induced in atoms or molecules.
Dispersion forces, which are also called London forces, usually increase with molar mass because molecules with larger molar mass tend to have more electrons, and dispersion forces increase in strength with the number of electrons. Furthermore, larger molar mass often means a bigger atom whose electron distribution is more easily disturbed because the outer electrons are less tightly held by the nuclei.
Because the noble gases are all nonpolar molecules, the only attractive intermolecular forces present are the dispersion forces.
The boiling point of the noble gas increases on moving down the group because of the increase in the dispersion force. Thus, option A is correct.
The noble gas has been consisted of the fully complete octet of the atom and has been less reactive in nature.
On moving down the group, there has been an increase in the number of shells of the atom with the increase in the atomic mass. The bigger molecules tend to have loosely bonded outermost electrons.
In noble gases, the force acting upon the molecule has been the Dispersion force. Since, the noble gas has a complete octet, the energy for removing the electrons and changing the state increase with the increase in the molecular mass.
The only force acting on the noble gases has been the dispersion force, Thus with an increase in the dispersion force, the boiling point increases. Thus, option A is correct.
For more information about the boiling point of the noble gases, refer to the link:
https://brainly.com/question/2289319
The last group on the periodic table is called the noble gases. The elements in this group are
all gases and are unreactive. Which property causes the noble gases to be unreactive?
A. atomic radius
B. atomic weight
C. full valence electron configuration
D. structure of the nucleus
Answer:
C
Explanation:
They are stabil and full of valence electron.
Considering the definition and properties of noble gases, a full valence electron configuration causes the noble gases to be unreactive. (option C)
Noble gasesNoble gases or inert gases are known as the set of chemical elements that constitute group 18 (VIIIA) of the Periodic Table of the elements.
Reactivity of noble gasesNoble gases have a very low chemical reactivity. This is because they have a complete valence shell that gives them a low tendency to capture or release electrons. For this reason they have also received the name of inert gases or rare gases.
In other words, the electronic configuration of the noble gases is that their outermost shell or valence shell is always complete, without the need to accept or give up electrons. Then they are in a state of maximum stability.
Because all chemical transformations involve valence electrons, noble gases do not participate in chemical reactions to form chemical compounds, since they are very stable on their own.
SummaryIn summary, a full valence electron configuration causes the noble gases to be unreactive. (option C)
Learn more about noble gases:
https://brainly.com/question/232282
https://brainly.com/question/13715159
https://brainly.com/question/11960526
#SPJ2
Draw the Lewis structure for (CH3)4NCl, a salt.
Answer:
See attached picture.
Explanation:
Hello,
In this case, for the given compound, since it is a salt, it contains a cation (positive charge) and an anion (negative charge), thus, since chlorine tends to gain electrons, it is negative whereas the nitrogen-containing side is positive, forming the anion and cation respectively. Moreover, for the drawing of its Lewis structure we must know that the chlorine is likely to interact via its seven valence electrons with nitrogen via its five valence electrons wherein four are bonded with four methyl radicals forming the tetramethylammonium chloride as shown on the attached picture.
We must realize that the nitrogen remain positively charged due to the presence of an extra bond with one methyl group (one carbon bonded to three hydrogens) which allow the formation of the salt.
Regards.
The Lewis structure for compound [tex](CH_3)_4NCl[/tex] is attached in the image below as an attachment.
Lewis structures are also called as electron dot structures and can be drawn if the molecular formula of a compound is known. It provides information regarding the nature of bond and the position of atoms .
They are also capable of exhibiting the lone pair if any present in a molecule or compound.Lewis defined a base to be an electron pair donor and an acid to be an electron pair acceptor.
Thus, the Lewis structure for compound [tex](CH_3)_4NCl[/tex] is attached in the image below as an attachment.
Learn more about Lewis structure,here:
https://brainly.com/question/4144781
#SPJ6
Which part of the immune system is a physical barrier?
skin
tears
mucus
stomach acid
Answer:
Which part of the immune system is a physical barrier?
> Skin.
How can individuals in communities prevent the global spread of hepatitis C?
> By avoiding the blood of other people.
A)skin is a physical barrier.
What type of barrier is skin?The physical barrier is incorporating the stratum corneum, corneocytes, and lipid layers, as well as the nucleated epidermis.
The skin provides an effective barrier between the organism and the environment, preventing the invasion of pathogens and fending off chemical and physical assaults, as well as the unregulated loss of water and solutes.
Learn more about physical barriers here: https://brainly.com/question/9162667
#SPJ2
How many mol of butan-1-ol are in 10.0 mL of butan-1-ol?
1) 0.165 mol
2) 0.109 mol
3) 0.943 mol
4) 0.258 mol
Answer:
2) 0.109 mol
Explanation:
The density of butan-1-ol is 0.8098g/mL. And its molar mass is: 74.121g/mol.
First, we need to convert volume of butan-1-ol to mass:
10.0mL * (0.8098g / mL) = 8.098g of butan-1-ol
Now, we need to convert these grams to moles using molar mass:
8.098g * (1mol / 74.121g) = 0.109 moles of butan-1-ol
Right answer is:
2) 0.109 molQuestion 2
Status: Not yet answered Points possible: 1.00
A graduated cylinder contains 10.00 mL water. A 14.74g piece of aluminum is added to the water, and the volume rises to 15.46
mL. What is the density of the aluminum in g/mL?
Type answer
Answer:
[tex]\rho = 2.7g/mL[/tex]
Explanation:
Hello,
In this case, given that the density for a material es defined via its mass and volume:
[tex]\rho =\frac{m}{V}[/tex]
We first need to compute the volume of aluminum in this case, since it comes from the volume of cylinder and the volume of the cylinder with the aluminum:
[tex]V=15.46 mL-10.00mL\\\\V=5.46mL[/tex]
In such a way, the density turns out:
[tex]\rho=\frac{14.74g}{5.46mL}\\ \\\rho = 2.7g/mL[/tex]
Best regards.
An element has two isotopes. 90% of the isotopes have a mass number of 20 amu, while 10% have a mass number of 22 amu. Calculate the Average Atomic Mass of the element
Explanation:
aam= 90%•20amu+10%•22amu/100
aam= 2020/100
aam= 20.2
Taking into account the definition of atomic mass, isotopes and atomic mass of an element, the average mass of the element is 20.2.
First of all, you have to know that atoms are made up of protons and neutrons in a central nucleus, as well as an electronic cloud (the extra-nuclear zone), a place where there is a greater probability of finding electrons orbiting the nucleus of the atom.
Then, it is neccesary to know that the atomic mass (A) is obtained by adding the number of protons and neutrons in a given nucleus.
The same chemical element can be made up of different atoms, that is, their atomic numbers are the same, but the number of neutrons is different. These atoms are called isotopes of the element.
This is, isotopes are atoms whose atomic nuclei have the same number of protons but different numbers of neutrons.
Because the isotopes of an element have different atomic masses, the relative atomic mass or atomic weight is an average of the atomic masses of the different isotopes in a sample taking into account the relative abundance of each of them.
In this case, 90% of the isotopes have a mass number of 20 amu, while 10% have a mass number of 22 amu. Then, the average mass of the element can be calculated as:
20 amu×0.90 + 22 amu×0.10= 20.2
Finally, the average mass of the element is 20.2.
Learn more:
brainly.com/question/14403750?referrer=searchResults brainly.com/question/10043246?referrer=searchResults brainly.com/question/15553207?referrer=searchResultsuppose you are titrating an acid of unknown concentration with a standardized base. At the beginning of the titration, you read the base titrant volume as 2.04 mL. After running the titration and reaching the endpoint, you read the base titrant volume as 20.95 mL. What volume, in mL, of base was required for the titration?
Answer:
18.91 ml
Explanation:
Initial volume of base=2.04 ml
Final volume of base = 20.95 ml
Volume of base used= 20.95 - 2.04 = 18.91 ml
Note that the volume of base used is obtained as the difference between the final and initial volume of base, hence the answer given above.
where is the fulcrum of this lever? circle and label its location on the diagram above
how do you balance the object on the measurement tray?
Answer:
Explanation:
1) A fulcrum is a pivot point that plays a central role (not necessarily located at the center) in a lever. The fulcrum of the attached picture has been circled (in blue).
2) The object placed on this lever's measurement tray is balanced by placing it at the center of the tray. This is the standard way of placing objects on any balance.
The fixed point on the rigid bar around which the machine (lever) can turn is called the fulcrum. It refers to the support that the lever rotates around. For instance, the midway or support is where the rod will pivot in the case of a common balance.
1) A fulcrum is a pivot point that plays a crucial (but not always essential) role in a lever. The accompanying image's fulcrum has been highlighted in blue with a circle.
2) By putting it in the middle of the measurement tray for this lever, the object is balanced. The norm for placing items on any balance is in this manner.
The pivotal point of the beam is known as the fulcrum. A load is applied at the other end of a lever when an effort is exerted on one end of the lever.
The fulcrum can be shown as follows:
To know more about fulcrum, visit;
https://brainly.com/question/29566369
#SPJ6
Whats the atomic radius of tin (Sn)
Explanation:
the atomic radius of ( Sn) is 225pm
The Earth's crust surrounds its
A. Mountains
B. volcanoes
C. mantle
D.valleys
Answer:
C. Mantle
Explanation:
mantle is the inside of the Earth
Answer:
C... i think
Explanation:
how many molecules of O2 are required?
Answer:
Question is incomplete.
which list of elements will behave similarly in a chemical reaction?
Answer:
Since elements in a group have the same number of valence electrons, they behave similarly in chemistry. An example would be the alkali metals (excepting hydrogen. Hydrogen is in this group only because it has one valence electron.
Explanation:
because it is
Given a solution of 5.0% by volume oleic acid in alcohol: Two drops (100 drops/cm3) are placed on a water surface and a continuous, circular film is formed 16.0 cm in diameter after all the alcohol has evaporated and the oil is distributed evenly on the surface. What would be the thickness of the layer of pure oil
Answer:
Thickness = 5.0 * 10^-6 to 1 significant figure
Explanation:
Volume of oleic acid added:
2 drops when there are 100 drops per cm³ means that each drop has a volume of;
2 * 0.01 = 0.02 cm³
A 5% v/v oleic acid in solution will contain:
5/100 * 0.02 = 0.001 cm³ of oleic acid .
Area of circular film on the water surface = πr²
where r, radius = 16 /2 = 8cm, π = 3.14
Area = 3.14 * 8²
Area = 201 cm²
Since volume = area * height or thickness
Thickness = volume/area
Thickness = 0.001 cm³ / 201 cm²
Thickness = 0.00000498 or 4.98 * 10^-6 cm
Thickness = 5.0 * 10^-6 to 1 significant figure
How many atoms of Oxygen are in 5H2PO3? A. 15 B. 8 C. 12
Please help!!
Answer:
15 atoms
Explanation:
plz mark as brainliest
what is the ability to transfer thermal energy to something else
Answer:
.Heat energy can be transferred from one object to another. The transfer or flow due to the difference in temperature between the two objects is called heat.
Explanation:
The transfer of thermal energy is called heat. In this process, thermal energy moves through a substance. For example, an ice cube has heat energy and so does a glass of lemonade.
Peptides can be separated using an ion-exchange column based on their isoelectric (pl) values. At which pH values would two different peptides, one with a pl of 5.0 and the other with a pi of 9.4, bind to a caution- and anion-exchange column? Each peptide may be capable of binding to each column at more than one pH value. anion-exchange column at pH = 3.0__________pH = 7.1__________ pH = 10.1_____________ cation-exchange column at pH = 3.0____________ pH = 7.1___________pH = 10.1___________
Answer:b
Explanation:
