What does ${\rm{BO}}{{\rm{D}}_5}$ represent?

Biological ozone depletion in five days

Dissolved oxygen left after five days

Micro-organisms killed by ozone in sewage treatment plants in five hours

Back to ENVIRONMENTAL CHEMISTRY

Your Progress

0 / 39 Answered

Correct

Incorrect

Accuracy

NEET • CHEMISTRY • ENVIRONMENTAL CHEMISTRY

Environmental chemistry practice · Mixed difficulty

Choose an answer to check it, or open “View answer” to study the explanation. Sign in to save progress to your account.

Practice format and chapter quiz

The practice player uses single-correct-answer MCQs. Chapter quizzes help you review a topic; they are not full-length NEET mock papers.

Take a chapter quiz →

Showing 31-39 of 39 questions

Preparing practice and saved progress…

31 Hard

31 of 39

Understanding +4 | -1

Which of the following statements are not correct?

(i)

{F^ - }

ion concentration above 2ppm causes brown
mottling in teeth.

(ii) Excessive

{F^ - }

(over 10 ppm) causes harmful effect to
bones and teeth.

(iii) Excessive lead in drinking water causes disease
methemoglobinemia

(iv) Deficiency of sulphate in drinking water causes
laxative effect.

View answer and explanation

Correct option: D

(iii) and (iv)

Option D ((iii) and (iv)) is correct because statements (iii) and (iv) are incorrect regarding the effects of lead and sulphate in drinking water.

32 Medium

32 of 39

Remembering +4 | -1

Photochemical smog does not contain

View answer and explanation

Correct option: B

S{O_2}

Option B (

S{O_2}

) is correct because photochemical smog is primarily formed by the action of sunlight on nitrogen oxides and volatile organic compounds, not sulfur dioxide.

33 Medium

33 of 39

Understanding +4 | -1

\mathrm{CFC}{\mathrm{l}_2}

is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen?

View answer and explanation

Correct option: D

\mathrm{C}{\mathrm{l}^\mathrm{*}}

Option D (

\mathrm{C}{\mathrm{l}^\mathrm{*}}

) is correct because chlorine free radicals are the species that react with ozone in the stratosphere, leading to its decomposition.

34 Easy

34 of 39

Remembering +4 | -1

Cyclone collector is used for minimising

View answer and explanation

Correct option: B

Air pollution

Option B (Air pollution) is correct because cyclone collectors are designed to remove particulate matter from air streams, thus minimizing air pollution.

35 Medium

35 of 39

Application +4 | -1

Haemoglobin contains

0.34 \%

of iron by mass. The number of

\mathrm{Fe}

atoms in

3.3 \mathrm{~g}

of haemoglobin is

(Given : Atomic mass of

\mathrm{Fe}

56 \mathrm{u}, \mathrm{N}_{\mathrm{A}}=6.022 \times

\left.10^{23} \mathrm{~mol}^{-1}\right)

View answer and explanation

Correct option: C

1.21 \times 10^{20}

Option C (

1.21 \times 10^{20}

) is correct because it is the calculated number of Fe atoms in 3.3 g of hemoglobin based on the given percentage and Avogadro's number.

36 Easy

36 of 39

Remembering +4 | -1

Mesosphere and thermosphere are collectively known as

View answer and explanation

Correct option: C

Ionosphere

Option C (Ionosphere) is correct because the ionosphere is the region of Earth's upper atmosphere, including the mesosphere and thermosphere, where ionization occurs.

37 Hard

37 of 39

Understanding +4 | -1

Which of the following sequence of T and F is correct for
given statements. Here T stands for True statement and
F stands for False statement.

(i) Troposphere is the lowest region of atmosphere in
which the human beings along with other organisms live.

(ii) Troposphere extends up to the height of 10 km from
sea level.

(iii) Stratosphere lies above troposphere, between 10 and
20 km above sea level.

(iv) Troposphere contains much little water vapour,
dinitrogen, dioxygen and ozone

(v) Stratosphere contains ozone, and cloud formation
also takes place in this region.

View answer and explanation

Correct option: C

TTFFF

Option C (TTFFF) is correct because statements (i) and (ii) are true, while (iii), (iv), and (v) are false.

38 Easy

38 of 39

Remembering +4 | -1

What does

\mathrm{BO}{\mathrm{D}_5}

represent?

View answer and explanation

Correct option: C

Dissolved oxygen consumed in five days

Option C (Dissolved oxygen consumed in five days) is correct because BOD5 specifically measures the amount of oxygen consumed by microorganisms in a water sample over a 5-day period.

39 Easy

39 of 39

Remembering +4 | -1

Green house effect is caused by

View answer and explanation

Correct option: D

\mathrm{C}{\mathrm{O}_2}

Option D (

\mathrm{C}{\mathrm{O}_2}

) is correct because carbon dioxide is a major greenhouse gas that traps heat in the atmosphere.

Revision notes and key takeaways

Review ENVIRONMENTAL CHEMISTRY in your textbook or class notes, then use this set to check your understanding.

Showing 31-39 of 39 questions

Your Progress

Environmental chemistry practice · Mixed difficulty

Continue Your Practice

Your practice