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
Butoxors [25]
3 years ago
15

Th e molar absorption coeffi cient of a substance dissolved in water is known to be 855 dm3 mol−1 cm−1 at 270 nm. To determine t

he rate of decomposition of this substance, a solution with a concentration of 3.25 mmol dm−3 was prepared. Calculate the percentage reduction in intensity when light of that wavelength passes through 2.5 mm of this solution.
Chemistry
1 answer:
Olegator [25]3 years ago
3 0

Answer : The percentage reduction in intensity is 79.80 %

Explanation :

Using Beer-Lambert's law :

A=\epsilon \times C\times l

A=\log \frac{I_o}{I}

\log \frac{I_o}{I}=\epsilon \times C\times l

where,

A = absorbance of solution

C = concentration of solution = 3.25mmol.dm^{3-}=3.25\times 10^{-3}mol.dm^{-3}

l = path length = 2.5 mm = 0.25 cm

I_o = incident light

I = transmitted light

\epsilon = molar absorptivity coefficient = 855dm^3mol^{-1}cm^{-1}

Now put all the given values in the above formula, we get:

\log \frac{I_o}{I}=(855dm^3mol^{-1}cm^{-1})\times (3.25\times 10^{-3}mol.dm^{-3})\times (0.25cm)

\log \frac{I_o}{I}=0.6947

\frac{I_o}{I}=10^{0.6947}=4.951

If we consider I_o = 100

then, I=\frac{100}{4.951}=20.198

Here 'I' intensity of transmitted light = 20.198

Thus, the intensity of absorbed light I_A = 100 - 20.198 = 79.80

Now we have to calculate the percentage reduction in intensity.

\% \text{reduction in intensity}=\frac{I_A}{I_o}\times 100

\% \text{reduction in intensity}=\frac{79.80}{100}\times 100=79.80\%

Therefore, the percentage reduction in intensity is 79.80 %

You might be interested in
Am I weird or is no one seeing my qn<br>free point by the way
Julli [10]

Answer:

 maybe they don't want to answer it  only if you give them a lot of points and brainliest they will answer it i think

Explanation:

5 0
2 years ago
Read 2 more answers
Uses of baking powder​
NARA [144]

Baking powder is used to increase the volume and lighten the texture of baked goods. It works by releasing carbon dioxide gas into a batter or dough through an acid–base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture.

7 0
3 years ago
Read 2 more answers
Which of the following will have the highest vapor pressure? (A: 1.0 M NaCl (aq)) (B:1.0 M MgCl2 (aq)) (C:1.0 M C12H22O11 (aq))
hjlf
The answer qill be b
7 0
3 years ago
Read 2 more answers
What coefficient should be placed before 02?<br> 2S+ __02 → 2S03
Trava [24]

Explanation:

\tt{2S+6O_2\implies{2SO_3}   }

5 0
3 years ago
Yet a third pair of compounds of manganese and oxygen is 50.48% and 36.81% oxygen respectively. In what small whole number ratio
Mariulka [41]

Answer:

The number ratio is 4:7

Explanation:

Step 1: Data given

Compound 1 has 50.48 % oxygen

Compound 2 has 36.81 % oxygen

Molar mass oxygen = 16 g/mol

Molar mass manganese = 54.94 g/mol

Step 2: Calculate % manganes

Compound 1: 100 - 50.48 = 49.52 %

Compound 2: 100 - 36.81 = 63.19 %

Step 3: Calculate mass

Suppose mass of compounds = 100 grams

Compound 1:

 50.48 % O = 50.48 grams

 49.52 % Mn = 49.52 grams

Compound 2:

36.81 % O = 36.81 grams

63.19 % Mn = 63.19 grams

Step 4: Calculate moles

Compound 1

Moles O = 50.48 grams / 16.0 g/mol = 3.155 moles

Moles Mn = 49.52 grams / 54.94 g/mol = 0.9013 moles

Compound 2

Moles O = 36.81 grams / 16.0 g/mol = 2.301 moles

Moles Mn = 63.19 grams / 54.94 g/mol = 1.150 moles

Step 5: calculate mol ratio

We will divide by the smallest amount of moles

Compound 1

O: 3.155/0.9013 = 3.5

Mn: 0.9013 / 0.9013 = 1

Mn2O7

Compound 2

O: 2.301 / 1.150 = 2

Mn: 1.150 / 1.150 = 1

MnO2

The number ratio is 2:3.5 or 4:7

7 0
3 years ago
Other questions:
  • Why does common table salt have a high melting point
    7·1 answer
  • The nucleus of the atom contains the greatest concentration of mass of an atom. which arrow is pointing at the nucleus of nitrog
    9·1 answer
  • How many atoms of Iodine are in a 12.75g sample of CaI2?
    14·2 answers
  • The chemical bond between which two atoms is most polar?<br> (1) C–N (3) S–Cl<br> (2) H–H (4) Si–O
    7·2 answers
  • Describe the effects of temperature and pressure on solubility. If you had used boiling water instead of lukewarm water, would y
    15·1 answer
  • What is the name of CaCl2 7H2o
    11·1 answer
  • Convert 12.8 cm to km.
    9·2 answers
  • For the reaction below, determine the standard free energy change, δg o. cu(s) + sn2+(aq) → cu2+(aq) + sn(s) e o cell =–0.48 v v
    6·1 answer
  • Help me out here please?
    5·1 answer
  • Why are there discontinuities in the interior of the earth...​
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!