Answer:
The types of cells at work in the human body
Explanation:
Rudolf Virchow was a German physician who is known as the father of modern pathology. He contributed to the development of the cell theory by concluding that all cells come from preexisting cells. This led to the conclusion that diseases occur at the cellular level, which allowed scientists to diagnose diseases more accurately.
Considering that Virchow analyzed human cells, the image that Tumu would be most likely to use in his assignment is the one of the types of cells at work in the human body.
Answer:
D the way root cells reproduce to increase root length
Explanation:
Have a good day!
Calculate Kb for a 0.1 M solution of cyanide ion, given that Ka for hydrocyanic acid is 6.2 x 10â10.a) 8.4 x 10â9b) 7.87 x 10â3c) 1.34 x 10â3d) 1.8 x 105e) 7.87 x 10â6f) 1.61 x 10â5g) 7.4 x 10â8
Answer:
Kb = 1.6 × 10⁻⁵
Explanation:
Step 1: Given data
Acid dissociation constant of hydrocyanic acid (Ka): 6.2 × 10⁻¹⁰
Concentration of cyanide ion (Cb): 0.1 M
Step 2: Calculate the basic dissociation constant (Kb) of cyanide ion
We have the Ka of HCN. We can calculate the Kb of its conjugate base using the following expression.
Ka × Kb = Kw = 1.0 × 10⁻¹⁴
Kb = 1.0 × 10⁻¹⁴/Ka
Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰
Kb = 1.6 × 10⁻⁵
The Kb for a 0.1 M solution of cyanide ion is :
- 1.6 × 10⁻⁵
Base dissociation constantGiven:
Acid dissociation constant of hydrocyanic acid (Ka)= 6.2 × 10⁻¹⁰
Concentration of cyanide ion (Cb)= 0.1 M
Base dissociation constant (kb)=?
Ka × Kb = Kw = 1.0 × 10⁻¹⁴
Kb = 1.0 × 10⁻¹⁴/Ka
Kb = 1.0 × 10⁻¹⁴/6.2 × 10⁻¹⁰
Kb = 1.6 × 10⁻⁵
Learn more about " Kb":
https://brainly.com/question/26871012?referrer=searchResults
an ionic bond is a force of _____between anions and ______when combined make _____compounds that are electrically_____
Nitrogen dioxide (NO2) gas and liquid water (H2O) react to form aqueous nitric acid(HNO3) and nitrogen monoxide gas. Suppose you have 2.0 mol of NO2 and 7.0 mol of H20 in a reactor. Calculate the largest amount of NHO3 that could be produced. Round your answer to the nearest 0.1 mol.
Answer:
1.3 moles of HNO₃ will be produced
Explanation:
Equation for the reaction:
3NO₂ + H₂O ----> 2HNO₃ + NO
From the equation of the reaction, 3 moles of NO₂ reacts with 1 mole of H₂O to produce 2 moles of HNO₃
Suppose there are 2 moles of NO₂ and 7.0 moles of H₂O in a reactor, the limiting reactant will be NO₂ and H₂O will be in excess since 3 moles of NO₂ reacts with every 1 mole of H₂O.
Since 3 moles of NO₂ reacts to produce 2 moles of HNO₃;
2 moles of NO₂ will react to produce 2/3 * 2 moles HNO₃ = 1.3 moles of HNO₃
Therefore, 1.3 moles of HNO₃ will be produced
The largest amount of HNO₃ produced from the reaction between 2 mole of NO₂ and 7.0 mole of H₂O in a reactor is 1.3 mole
We'll begin by determining the limiting reactant. This can be obtained as follow:
3NO₂ + H₂O —> 2HNO₃ + NO
From the balanced equation above,
3 moles of NO₂ reacted with 1 mole of H₂O.
Therefore,
2 moles of NO₂ will react with = [tex]\frac{2}{3}\\\\[/tex] = 0.67 mole of H₂O.
From the calculation made above, we can see that only 0.67 mole of H₂O out of 7 moles given, reacted completely with 2 moles of NO₂. Thus, NO₂ is the limiting reactant and H₂O is the excess reactant. Finally, we shall determine the largest amount of HNO₃ produced from the reaction. This can be obtained by using the limiting reactant as illustrated below:From the balanced equation above,
3 moles of NO₂ reacted to produce 2 moles of HNO₃.
Therefore,
2 moles of NO₂ will react to produce = [tex]\frac{2 *2 }{3} \\\\[/tex] = 1.3 mole of HNO₃.
Thus, the largest amount of HNO₃ produced from the reaction is 1.3 mole
Learn more: https://brainly.com/question/8620653
what is filtration??
Answer:
the action or process of filtering something.
Explanation:
Filtration is a physical, biological or chemical operation that separates solid matter and fluid from a mixture with a filter medium that has a complex structure through which only the fluid can pass.
These questions are from an experiment where we had a mixture of Ferrocene, acetylferrocene and diacetyl ferrocene and we separated each by using column chromatography. Before doing the column chromatography we did TLC analysis to ensure that we did, in fact, have a mixture of these 3 compounds.
During the column chromatography we first eluted the ferrocene using pure hexane. Then we eluted the acetylferrocene using a 1:1 mixture of hexane and methylene chloride. Then we eluted the diacetylferrocene using a 9:1 mixture of hexane and methylene chloride.
1. Rank ferrocene, acetylferrocene, and diacetylferrocene in order of increasing polarity. Do the TLC results from your fractions support this ranking? Explain.
2. Rank the solvents used in the experiment in order of increasing polarity.
3. Why do you start with the least polar solvent/solvent mixture and progress to increasing polar solvent/solvent mixtures when eluting the ferrocene compounds from the column rather than starting with more polar solvent system and progressing to less polar solvents?
4. How do the thin layer and column chromatography for this experiment compare in regard to stationary and mobile phases?
5. What key feature in the IR spectrum of acetylferrocene distinguishes it from the spectrum of ferrocene?
Answer:
Explanation:
The polarity of the 3 compounds would be in the order of
Ferrocene < Acetylferrocene < Diacetylferrocene
Your TLC data has to also support this observation . This can be checked by measuring the values of Rf ( Retention factor = distance travelled by solute/solvent ) .The Rf values also has to follow this particular order: -
Ferrocene > acetylferrocene > diacetylferrocene
2) Hexane happens to be a non-polar solvent. The polarity of hexane can be increased if some polar solvents for example, ethyl and methylene chloride etc are added
Therefore, in the increasing order of solvents polarity, we have
Hexane < 1:1 mixture of hexane: methylene chloride < 9:1 mixture of methylene chloride:
3) Chromatographic techniques all have a stationary phase in addition to a mobile phase. In the case of column chromatography, the silica gel will be the stationary phase and the solvent that will be poured will be the mobile phase.
4) The TLC and column chromatography both happen to have the same stationary phase which is the silica gel. Also, the same solvent mixture is used in both the techniques. This makes the result of the 2 to be almost the same. The difference seen between them is that, TLC works against the gravity while on the other hand column chromatography works in the direction of the gravity.
5) The key feature in the IR spectra of the acetylferrocene that will be absent in the spectra of ferrocene is the presence of carbonyl stretching frequency at close to 1700 per cm(cm-1). This peak is easily differentiated between both acetyl ferrocene and ferrocene.
A gas sample has a gas density of 5.95 g/L at 100°C and 755 mmHg. Determine the molar mass of the gas.
Answer:
M = 184.1 g/mol
Explanation:
Given data:
Density = 5.95 g/L
Temperature = 100°C (100+273 = 373 K)
Pressure = 755 mmHg = (755/760 = 0.99 atm )
Molar mass of gas = ?
Formula:
d = PM/RT
Solution:
M = dRT / P
M = 5.95 g/L × 0.0821 atm.L/mol.K × 373 K/ 0.99 atm
M = 182.21atm.g/mol / 0.99 atm
M = 184.1 g/mol
What mass of a solution labeled 6.3% sucrose (C12H22O11, 342 g/mol) by mass contains 11.0 g of sucrose?
Answer:
174.6g of solution contains the 11.0g of sucrose
Explanation:
A solution of 6.3% by mass of sucrose contains 6.3g of sucrose in 100g of solution, that is, 6.3g of sucrose / 100g of solution.
As we want to find the mass contains 11.0g of sucrose, we can write:
11.0g of sucrose * (100g of solution / 6.3g of solution) =
174.6g of solution contains the 11.0g of sucroseNitrogen gas at 300 k and 200 kpa is throttled adiabatically to a pressure of 100 kpa if the change in kinetic energy is negligble the temperature of the nitrogen after throttling will be:_________
Answer:
The temperature of the Nitrogen after throttling is [tex]T_2 = 300 \ K[/tex]
Explanation:
From the question we are told that
The temperature is [tex]T_1 = 300 \ K[/tex]
The pressure is [tex]P = 200 \ kPa = 200 * 10^{3} \ Pa[/tex]
The pressure after being [tex]P_1 = 100 \ kPa = 100 * 10^{3} \ Pa[/tex]
Generally from the first law of thermodynamics we have that
[tex]Q - W = \Delta U + \Delta K[/tex]
Here [tex]\Delta U[/tex] is the change internal energy which is mathematically represented as
[tex]\Delta U = C_p (T_2 - T_1)[/tex]
Here [tex]C_p[/tex] is the specific heat of the gas at constant pressure
[tex]\Delta K[/tex] is the change kinetic energy which is negligible
Q is the thermal energy which is Zero for an adiabatic process
W is the work done and the value is zero given that the gas was throttled adiabatically
So
[tex]0= \Delta U +0[/tex]
=> [tex]\Delta U = 0[/tex]
=> [tex](T_2 - 300) = 0[/tex]
=> [tex]T_2 = 300 \ K[/tex]
Which element is most likely suspected?
iron
Sulfur
Chromium
Nickel
Answer: sulfur
Explanation:
Answer:
its sulfur babes
Explanation:
Look at the picture below. Name the isotope
Calcium-19
Calcium-39
Potassium-20
Potassium-39
Are light and other forms of energy are made of atoms
Answer:
yes they are
Explanation:
An Sulfur tetrafluoride gas is collected at 23.0 °C in an evacuated flask with a measured volume of 20.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.230 atm . Calculate the mass and number of moles of sulfur tetrafluoride gas that were collected. Be sure your answer has the correct number of significant digits. mass: 1 g N10 mole: mol X & ? Explanation Check
mass = 20.48 g
moles=0.1895
Further explanationIn general, the gas equation can be written
Pv=nRTwhere
P = pressure, atm
V = volume, liter
n = number of moles
R = gas constant = 0.08205 L.atm / mol K
T = temperature, Kelvin
P=0.23 atm
V=20 L
T=23+273=296 K
[tex]\tt n=\dfrac{PV}{RT}=\dfrac{0.23\times 20}{0.082\times 296}=0.1895[/tex]
mass SF₄ (MW=108,07 g/mol) :
[tex]\tt 0.1895\times 108,07 g/mol=20.48~g[/tex]
An atom of an element has two electrons in the first energy level and five electrons in the second energy level. Write the electron configuration and name the element. How many unpaired electrons does an atom of this element have?
Answer:
electronic configuration: 1s^2,2s^2,2p^3
name: nitrogen
unpaired electron: 3
Explanation:
The atom with 2 electrons and 5 electrons in the first and second energy level is NITROGEN. The element has 3 unpaired electron.
The electronic configuration of the atom is 1s² 2s² 2p³Since the atom has 7 Electrons, the element which has 7 electrons is NITROGEN. The 2p orbital has 3 unpaired electrons in it's second energy level.Therefore, the 2p orbital has 3 unpaired electrons in it's outermost shell.
Learn more :https://brainly.com/question/19328396
Please help I will give brainiest
Answer:
Answer
Answer is option B coz da negative charge r more thn positive
Answer:
B.
Explanation:
On the hand in the option B there are 3 positive and 5 negative signs so the answer is B.
QUESTION 24
Calculate [H 30+] of a solution with a pH of 2.14.
Answer:
The hydronium ion concentration can be found from the pH by the reverse of the mathematical operation employed to find the pH. [H3O+] = 10-pH or [H3O+] = antilog (- pH).
I hope what I just explained is enough .
branches of sicence
Answer:
Natural science can be divided into two main branches
Explanation:
life science and physical science. Life science is alternatively known as biology, and physical science is subdivided into branches: physics, chemistry, astronomy and Earth science.
Answer:
Astronomy
Biology
Geology
Chemistry
Please Mark Brainliest and rate me 5
Thank You Good Night / Good Day to you
Please help on the image below.
Heat capacity of Calorimeter = 10.7 J/°c
Further explanationHeat lost=Heat gained
Q in = Q out
-Q lost(hot water)=Q gained (cold water+calorimeter)
-m.c.Δt=m.c.Δt+C.Δt
[tex]\tt \rightarrow -50\times 4.18\times (32.7-43)=50\times 4.18\times (32.7-22.9)+(32.7-22.9)\times C_{cal}\\\\\rightarrow 2152.7=2048.2+9.8\times C_{cal}\\\\104.5~J=9.8\times C_{cal}\\\\C_{cal}=\dfrac{104.5}{9.8}=10.7~J/^oC[/tex]
Roughly how many water molecules are ionized at any given time in a sample of room-temperature water? a. one in a thousand b. one in a million c. one in a billion d. one in a trillion
Answer:
one in a billion
Explanation:
We have it known that Pure water is entirely made up of H2O molecules. Just 1 in 10⁹, that is a billion molecules are ionized when it is at room temperature.
The Ionization of water has this chemical equation:
H2O <--> H+ + OH-
When At equilibrium and at room temperature, we have the rate of forward reaction and the backward reaction to be very fast such that no water molecule would eventually remain ionized.
Therefore our answer is roughly one in a billion water.
A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond?
Answer:
A(n)___ is the smallest neutral unit of two or more atoms held together by a covalent bond?
=>MOLECULE
Arrange the following compounds in order of increasing acidity, and explain the reasons for your choice of order. Enter your answer in the answer box below. a. 4-nitrophenol b. cyclohexanol c. 2,6-difluorocyclohexanol d. 4-bromophenol
Answer:
(a) > (d) > (c) > (b)
Explanation:
Acidic character is based upon inductive effect of the functional group that are attached to parent chain.
1. Nitro is a -I group which makes phenol acidic due to increased resonance, 2. bromine is a -I group but it is weaker than nitro group
3. phenol is more acidic than cyclohexanol due to resonance stabilization of resonance and among halogen F>Cl>Br>I is the order of acidity
4. cyclohexanol will be weakest as it is not associated with any -I groups here.
so the order of acidity will be
(a). 4-nitropheno > (d). 4-bromophenol > (c). 2,6-difluorocyclohexanol > (b). cyclohexanol
a solution is dilute when?
A. it has a lot of solute
B. has little solvent
C. it has a lot of solvent
D. has maximum solute
How would you synthesize 1-hexanol starting from 1-propanol, incorporating a Grignard reagent in the synthesis?
Answer:
hjhjhjhhhhh
Explanation:
What elements make up water?
Answer:
1 oxygen and 2 hydrogen
element that is the "best" at removing electrons from other atoms.
Answer:
Fluorine
Explanation:
Fluorine is the "best" at removing electrons because it has 5 electrons on its second shell. The 5 electrons are really close and are trying to drag in another electron to complete the shell and have all 6 electrons to complete the valence shell.
What is the mole fraction of each component if 3.9 g of benzene (C6H6) is dissolved in 4.6 g of toluene (C7H8)
Answer:
Step 1 of 6
(a)
The mass of benzene is  , so calculate the moles of benzene as follows:

The mass of toluene is, so calculate the moles of toluene as follows:

Now, calculate the mole fraction as follows:


Therefore, the mole fraction of benzene and toluene is  and  respectively.
Step 2 of 6
(b)
The formula to calculate the partial pressure is as follows:

Here,  is the partial pressure of benzene,  is the vapour pressure of pure benzene and  is the mole fraction of benzene.
Vapour pressure of pure benzene at  is.
Substitute the values in the equation as follows:

Therefore, the partial pressure is  .
Step 3 of 6
(c)
Vapor pressure of the solution at 1 atm is  .
When the total pressure of the vapour pressure of the mixture is  at a temperature, then, the solution boils. It corresponds to the boiling point of the solution.
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is less than the atmospheric pressure, the solution will not boil at  .
Calculate the total pressure of the solution at  as follows:

Since, the total pressure is greater than the atmospheric pressure, the solution will boil at  .
Therefore, the boiling point of the solution is  .
Step 4 of 6
(d)
Mole fraction of benzene at  is calculated as follows:

Mole fraction of toluene at  is calculated as follows:

Therefore, the mole fractions of benzene and toluene are  and  respectively.
Step 5 of 6
(e)
Vapor pressure of benzene at  is  .
Partial pressure of benzene is calculated as follows:

Vapor pressure of toluene at  is  .
Partial pressure of toluene is calculated as follows:

Step 6 of 6
Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Weight composition of the vapour that is in equilibrium with the solution is calculated as follows:

Explanation:
mark me as brainliest
What is the temperature 0 Kelvin called?
What happens at that temperature?
Answer:
0 Kelvin is called Absolute Zero. Particles will stop moving, and lose all energy.
Are transition metals reactive?
Answer: Yes
Explanation:
(a) Given that the path length of the cuvette is 1 cm, what is the extinction coefficient of the 0.020 mM Yellow 5 dye at lambda max?(b) Given the data in the table below, what is the concentration of the diluted solution?Stock solution concentration 0.075 MStock solution absorbance 1.84Diluted solution absorbance 0.78
Answer:
(a). Kindly check the explanation section.
(b). 24.5 M^-1 cm^-
(c). 0.0318 M
Explanation:
So, we are given the following data parameters which is going to aid us in solving the above Question;
The path length = 1cm, extinction coefficient = unknown, absorbance is unknown and concentration= 0.02mM.
Using the formula below; we can determine the extinction coefficient as;
Absorbance = extinction coefficient × concentration × path length. -----------(1).
(a). Since, the absorbance is not given in the Question it won't be possible to determine the value of the extinction coefficient. Thus, say the value of absorbance = A.
Then, extinction coefficient = A/ 0.02 × 1 cm.
(b). Making use of the formula above, the extinction coefficient can be Determine as follows;
extinction coefficient = 1.84/0.075 × 1 = 24.5 M^-1 cm^-1.
(c). The concentration can be Determine by also making use of the formula above and making the concentration the subject of the formula;
Concentration = absorbance/ extinction coefficient × path length.
Concentration = 0.78/24.5 M^-1 cm^-1. × 1cm = 0.0318 M.
A strong electrolyte is one that ________ completely in solution. a) reacts.b) decomposes.c) disappears.d) ionizes.
Answer:
A.
Explanation:
elctrolytes decomposes
Answer:
D. ionizes
Explanation:
What is the mass, in grams, of 2.3 moles of gold?
Answer:
453.031g
Explanation:
atomic mass (molar mass)- 196.97g/m
2.3(196.97)=453.031