Explore topic-wise MCQs in Organic Chemistry Questions and Answers.

This section includes 4 Mcqs, each offering curated multiple-choice questions to sharpen your Organic Chemistry Questions and Answers knowledge and support exam preparation. Choose a topic below to get started.

1.

A substance absorbs 2.0 x 1016 quanta or radiations per second and 0.002 mole of it reacts in 1200 seconds. What is the quantum yield or the reaction (N = 6.02 x 1023)?

A. 50
B. 40
C. 80
D. 100
Answer» B. 40
Discussion
2.

A 0.1 M solution of compound A shows 50% transmittance when a cell of 1 cm width is used at λ1 nm. Another 0.1 M solution of compound B gives the optical density value of 0.1761 using 1cm cell at λ1 nm. What will be the transmittance of a solution that is simultaneously 0.1 M in A and 0.1 M in B using the same cell and at the same wave length? [log 1.301; log 1.4771; log 50 = 1.699].

A. 33.3%
B. 50%
C. 66.7%
D. 70%
Answer» B. 50%
Discussion
3.

The molar extinction coefficient of B (MW = 180) is 4 x 103 L mol-1 cm-1. One-liter solution of C which contains 0.1358 g pharmaceutical preparation of B, shows an absorbance of 0.411 in a 1 cm quartz cell. What is the percentage (w/w) of B in the pharmaceutical preparation?

A. 10.20
B. 13.60
C. 20.40
D. 29.12
Answer» C. 20.40
Discussion
4.

Which regions of the light radiations of the visible ultraviolet lying between – wavelength are chiefly concerned in bringing about photochemical reactions?

A. 1000 Å and 2000 Å
B. 1500 Å and 1000 Å
C. 8000 Å and 2000 Å
D. 19000 Å and 12,000 Å
Answer» D. 19000 Å and 12,000 Å
Discussion