GATE Overflow for GATE ESE - Recent activity in Fundamentals of Environmental Chemistry

Edited: GATE ES 2025 | Question: 23

Mon, 02 Jun 2025 19:36:40 +0000

Choose the correct option(s) from the following regarding cumulative toxicity

Bioaccumulation is the process by which a living organism keeps on accumulating pollutants in its body due to continuous exposure, whereas, bio-magnification is the process by which higher order organisms accumulate more pollutants than the lower order organisms in a food chain.
Biomagnification is the process by which a living organism keeps on accumulating pollutants in its body due to continuous exposure, whereas, bioaccumulation is the process by which higher order organisms accumulate more pollutants than the lower order organisms in a food chain.
Bioaccumulation and biomagnification are possible with heavy metals, but not with pesticides and pharmaceutical compounds.
Bioaccumulation and biomagnification are possible with heavy metals, pesticides and pharmaceutical compounds

Edited: GATE ES 2025 | Question: 16

Mon, 02 Jun 2025 16:52:46 +0000

Consider the following statements related to nitrification process:

Electron acceptor type vary depending on whether nitrosomonas or nitrobacter is involved.
Predominant carbon source is organic matter.
Predominant carbon source is inorganic carbon.
Electron donor during conversion of ammonium ions to nitrite ions is ammonium ions.

Choose the correct option(s) from the following

$(iii)$ and $(iv)$ are correct
$(i)$ and $(ii)$ are correct
$(i)$ is incorrect and $(iii)$ is correct
$(ii)$ is correct and $(iii)$ is incorrect

Recategorized: GATE ES 2024 | Question: 50

Mon, 21 Apr 2025 17:02:20 +0000

Two hypothetical organic waste streams A and B are mixed prior to the composting process. Waste-A has $2.16 \%$ of $\mathrm{C}$ and $1.20 \%$ of N. Waste-B has $19.10 \%$ of $\mathrm{C}$ and $0.14 \%$ of N. The quantity of Waste-B that should be mixed with per kg of Waste-A to achieve the desired C:N ratio of 25 is __________ $\mathrm{kg}$ $\text{(rounded off to $2$ decimal places)}$.

Assume both the waste streams are completely dry.

Recategorized: GATE ES 2024 | Question: 55

Mon, 21 Apr 2025 17:02:11 +0000

Initially a bottle contained $400 \mathrm{~g}$ of ethanol. Half of ethanol was used by a student for preparing the stock solution in an environmental chemistry laboratory just before summer vacation of $90$ days. After completing the procedure, the student left the bottle uncorked. If the unsealed bottle losses ethanol at a rate of $0.5 \mathrm{~g} /$ day, the ethanol that will be left in the bottle at the end of the summer vacation is ___________ $\mathrm{g}$ $\text{(an integer value)}$.

Recategorized: GATE ES 2023 | Question: 32

Mon, 21 Apr 2025 17:00:03 +0000

Read the following statements

I. According to the Liebig's law of minimum, the growth is regulated by the limited factors i.e., resources in scarcity and not by the resources in abundance.

II. Shelford's law of tolerance states that, only the factors present in excess/abundance can affect the growth, development of an organism or rate of biological process.

III. Shelford's law of tolerance states that, an organism's success is based on a complex set of conditions and that each organism has a certain minimum, maximum, and optimum levels of environmental factor or combination of factors that determine success.

The correct choice is

$\text{I}$ and $\text{II}$ are correct; $\text{III}$ is incorrect
$\text{I}$ and $\text{III}$ are correct; $\text{II}$ is incorrect
$\text{II}$ is correct; $\text{I}$ and $\text{III}$ are incorrect
$\text{III}$ is correct; $\text{I}$ and $\text{II}$ are incorrect

Recategorized: GATE ES 2022 | Question: 18

Mon, 21 Apr 2025 16:47:09 +0000

If G represents Gibbs free energy, select the correct statement(s)

If $\Delta \mathrm{G}=0$, reaction will proceed only in one direction
If $\Delta \mathrm{G}=0$, reaction will be in equilibrium
If $\Delta \mathrm{G}<0$, reaction will proceed forward
If $\Delta \mathrm{G}>0$, reaction will not proceed forward

Recategorized: GATE ES 2022 | Question: 40

Mon, 21 Apr 2025 16:46:10 +0000

Carbon cycle, nitrogen cycle and phosphorus cycle play important role in the ecosystems. Which of the following statement(s) is/are NOT correct about the phosphorus cycle?

Shortage of phosphorus can be a limiting factor in many ecosystems, however, its excess can stimulate eutrophication.
Organic phosphates exist in various rock and soil minerals.
Like carbon cycle, phosphorus also has a gaseous phase and can move into far away ecosystems.
Human interventions like application of phosphorus fertilizers cause much phosphorus to get into the ocean.

Recategorized: GATE ES 2021 | Question: 3

Mon, 21 Apr 2025 15:42:40 +0000

The table below shows the carbon content of four samples of powdered coal. If these four samples are mixed completely, what would be the resultant carbon percentage of the mixture by weight?
\begin{array}{|c|c|c|}
\hline Sample number & Mass of sample (kg) & Carbon \% by weight \\
\hline 1 & 2 & 88 \\
\hline 2 & 1 & 90 \\
\hline 3 & 2 & 80 \\
\hline 4 & 1 & 90 \\
\hline
\end{array}

$58 \%$
$86 \%$
$87 \%$
$90 \%$

Recategorized: GATE ES 2021 | Question: 16

Mon, 21 Apr 2025 15:42:05 +0000

The oxidation states of ' $\mathrm{N}$ ' in $\mathrm{NH}_{4}^{+}, \mathrm{NO}_{2}^{-}$, and $\mathrm{NO}$ are ________ respectively.

$+2,-3$, and +3
$-3,+3$, and +2
$-3,+3$, and -4
$+4,-2$, and +2