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
How many molecules are there in 0.75 mol NH3
vitfil [10]
3 *0.75 = 2.25 mol that’s is ur answer for this question
4 0
3 years ago
Consider phosphoric acid, H3PO4. What is the total number of moles of H+ available for reaction in 4.50 L of 0.750 MH3PO4? Write
NeX [460]
Idk.................
8 0
3 years ago
A chemist determined by measurements that 0.030 moles of barium participated in a chemical reaction. Calculate the mass of bariu
schepotkina [342]

Answer: 4.1 g of barium precipitated.

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number 6.023\times 10^{23} of particles.

To calculate the moles, we use the equation:

\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}

Given : moles of barium = 0.030

Molar mass of barium = 137 g/mol

0.030=\frac{x}{137}

x= 4.1 g

Thus there are 4.1 g of barium that precipitated.

3 0
3 years ago
What is the hydrosphere and<br> Where is<br> it found ?
Anastasy [175]

Answer:it is all of the body's of water on the earth such as lakes seas and something over the earthearth's serface like clouds

Explanation:o

3 0
2 years ago
A piece of silver is observed to be scratched bent and coated with tarnish. which is the chemical change?
Tomtit [17]

Answer:

The answer is D.

Explanation:

Silver consists of 92.5% silver, and the remaining part is copper. ... Pure silver is not susceptible to tarnish in a pure oxygen environment. However, the copper that is contained in 925 sterling silver may react to the ozone and hydrogen sulfide in the air and cause sterling silver to tarnish.

4 0
3 years ago
Read 2 more answers
Other questions:
  • What is the main component of the earths ancient atmosphere?
    13·1 answer
  • What is colligative property? why does theproperty changes the way that it does when the amount of solute is increased. State an
    15·1 answer
  • Khalad is measuring the amplitude of a wave. What can be known about this wave?
    15·2 answers
  • 1. Define λmax and explain why it is desirable to do the experimental procedure at λmax? 2. Around what absorbance would you exp
    5·1 answer
  • How many moles of ammonium sulfate. are required to create 200 liters of a 3 M solution ​
    14·1 answer
  • A compound has an empirical formula of C2H5. What is true about this empirical formula?
    9·1 answer
  • When an acid or vase is added to to water,
    14·1 answer
  • Fill in the chart to identify how scientists represent matter and chemical changes in matter.
    12·1 answer
  • What is a part's structure related to?
    6·1 answer
  • Nitrate has the formula \textit {NO}_\textit3^-NO
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!