1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Degger [83]
3 years ago
15

A 3.96x10^-24 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000-cm cuvet; a blank solution containi

ng only solvent had an absorbance of 0.029 at the same wavelength. Find the molar absorptivity of compound A.
Chemistry
1 answer:
viktelen [127]3 years ago
4 0

Actual question from source:-

A 3.96x10-4 M solution of compound A exhibited an absorbance of 0.624 at 238 nm in a 1.000 cm cuvette.  A blank had an absorbance of 0.029.  The absorbance of an unknown solution of compound A was 0.375.  Find the concentration of A in the unknown.

Answer:

Molar absorptivity of compound A = 1502.53\ {Ms}^{-1}

Explanation:

According to the Lambert's Beer law:-

A=\epsilon l c

Where, A is the absorbance

 l is the path length  

\epsilon is the molar absorptivity

c is the concentration.  

Given that:-

c = 3.96\times 10^{-4}\ M

Path length = 1.000 cm

Absorbance observed = 0.624

Absorbance blank = 0.029

A = 0.624 - 0.029 = 0.595

So, applying the values in the Lambert Beer's law as shown below:-

0.595=\epsilon\times 1.000\ cm\times 3.96\times 10^{-4}\ M

\epsilon=\frac{0.595}{3.96\times 10^{-4}}\ {Ms}^{-1}=1502.53\ {Ms}^{-1}

<u>Molar absorptivity of compound A = 1502.53\ {Ms}^{-1}</u>

You might be interested in
Give the name and symbol of your favorite element and explain why it your favorite element.​
Salsk061 [2.6K]

Answer:

The most important elements that we use in everyday life include carbon, hydrogen, oxygen, with smaller amounts of things like chlorine, sulfur, calcium, iron, phosphorus,nitrogen, sodium, and potassium. Apart from these, other elements include magnesium, zinc, neon, and helium are also in our daily existence.

all these element are my favourite element .......

6 0
2 years ago
If during an experiment zinc was found to be more reactive than lead or copper, zinc would be considered the strongest _____.
densk [106]

Zinc would be considered the strongest reducing agent.

<h3>Reducing agent</h3>

A reducing agent is a chemical species that "donates" one electron to another chemical species in chemistry (called the oxidizing agent, oxidant, oxidizer, or electron acceptor). Earth metals, formic acid, oxalic acid, and sulfite compounds are a few examples of common reducing agents.

Reducers have excess electrons (i.e., they are already reduced) in their pre-reaction states, whereas oxidizers do not. Usually, a reducing agent is in one of the lowest oxidation states it can be in. The oxidation state of the oxidizer drops while the oxidizer's oxidation state, which measures the amount of electron loss, increases. The agent in a redox process whose oxidation state rises, which "loses/donates electrons," which "oxidizes," and which "reduces" is known as the reducer or reducing agent.

Learn more about reducing agent here:

brainly.com/question/2890416

#SPJ4

<h3 />
5 0
2 years ago
What pressure is required to compress 196.0 liters of air at 1.83 atmosphere into a cylinder whose volume is 26.0 liters
drek231 [11]

Answer:

P₂ = 13.79 atm

Explanation:

Given data:

Initial volume = 196.0 L

Initial pressure = 1.83 atm

Final volume = 26.0 L

Final pressure = ?

Solution:

The given problem will be solved through the Boyle's law,

"The volume of given amount of gas is inversely proportional to its pressure by keeping the temperature and number of moles constant"

Mathematical expression:

P₁V₁ = P₂V₂

P₁ = Initial pressure

V₁ = initial volume

P₂ = final pressure

V₂ = final volume  

Now we will put the values in formula,

P₁V₁ = P₂V₂

1.83 atm × 196.0 L = P₂× 26.0 L

P₂ = 358.68 atm. L /  26.0 L

P₂ = 13.79 atm  

5 0
3 years ago
Fe2O3 + 2Al = 2Fe + Al2O3 is this a redox reaction
katovenus [111]

Answer:

<h3>2Al+ Fe2O3 gives 2Fe + Al2O3. The given reaction is a redox reaction. As oxidation and reduction are taking place simultaneously.</h3>

Explanation:

like this...Identify oxidation and reduction with their agents:

<h3>•2Al+ Fe2O3 →2Fe + Al2O3</h3>

<h3>•Fe2O3 is reduced to Fe whereas Al is oxidized to Al2O3</h3>

<h3>In the above reaction:</h3>

<h3>Oxidizing agent:Fe2O3</h3>

<h3>Reducing agent:Al</h3>

I hope it's help you (◠‿・)—☆

5 0
3 years ago
Glycolic acid, which is a monoprotic acid and a constituent in sugar cane, has a pKa of 3.9. A 25.0 mL solution of glycolic acid
slava [35]

Answer:

pH of resulting solution = 7.98

Explanation:

The balanced equation  

HA + NaOH - Na+ + A- + H2O

Number of moles of A = Number of moles of HA  = Number of moles of NaOH

= 35.8/1000 * 0.020 = 0.000716 mol

Initial concentration of A = 0.000716/0.0608 = 0.01178 M

pKb = 14 – pKa = 14 -3.9 = 10.1

Kb = 10^{-Kb} = 10^{-10.1} = 7.943 * 10^-11

Kb = [HA][OH-]/[A-]

Kb = a^2/(0.01178 -a) = 7.943 * 10^-11

a^2 + 7.943 * 10^-11 a – 9.357 * 10^-13 = 0

a = 9.673 * 10^-7

OH- = a = 9.673 * 10^-7 M

pOH = -log [OH-] = -log (9.673 * 10^-7) = 6.02

pH = 14-6.02 = 7.98

8 0
2 years ago
Other questions:
  • A proposed mechanism for the reaction Cl2(g) + CHCl3(g)  HCl(g) + CCl4(g) in the atmosphere is Step 1: Cl2(g) 2 Cl(g) (very f
    6·1 answer
  • The number of moles of solute dissolved per liter of solution; also known as molar concentration.
    10·1 answer
  • What is radium used for
    10·1 answer
  • 3. Rank each of the following in order of DECREASING atomic radius<br> a. Cl, Br, Ga
    9·1 answer
  • Which is correct? not sure which is right
    6·1 answer
  • In this equilibrium, hydroxide ion acts as a A) Lewis base B) Bronsted base C) both A &amp; B D) neither A or B
    12·1 answer
  • Is it possible to identify something as an element, compound or pure substance
    15·1 answer
  • Which of the following single replacement reactions will take place?
    8·1 answer
  • Write a balanced half-reaction for the oxidation of gaseous nitric oxide NO to nitrate ion NO−3 in acidic aqueous solution. Be s
    11·1 answer
  • Americium-241 undergoes fission to produce three neutrons per fission event. if a neutron-absorbing material is mixed in with th
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!