Question

The value of $2,4$-D is $25$ ppm. How much $2,4$-D should require for making its $5$ litres, $15$ litres and $25$ litres solutions respectively.
a) $25gm,50gm,75gm$
b) $50gm,175gm,525gm$
c) $250gm,750gm,1250gm$
d) $125gm,375gm,625gm$

Answer 1

Hint: As we know ppm is the abbreviated form of parts per million and it can also be expressed as milligrams per liter. This measurement is said to be the mass of a chemical or contaminate per unit volume of water. Parts per million can be defined as the ratio of the number of parts of the component to the total number of parts of all components of the solution multiplied by ${10^6}$.

Complete answer:
2,4-Dichlorophenoxyacetic acid (2,4-D) is a common systemic herbicide used in the control of broadleaf weeds.
As we know $1$ ppm is equal to $1$ gm per litre.
Therefore we can say that,
$25$ppm is equal to $25$ gm per litre.
Hence,
for $5$ litres, amount needed is five times twenty five = $125gm$
for $15$ litres, amount needed is fifteen times twenty five = $375gm$
for $25$ litres, amount needed is twenty five times twenty five = $625gm$

So the correct option is D which states that $125gm, 375gm, 625gm$.

When the concentration of the toxic substances is high enough to cause damage to living organisms, we can say the soil is contaminated.
The main causes of soil pollution can be due to one of the following like agriculture, excessive industrial activity and poor management or inefficient disposal of waste.

Note:
Parts per million is a method of expressing very dilute concentrations of the substances. Just like per cent means out of a hundred, therefore parts per million or ppm means out of a million. Usually it describes the concentration of something in water or soil. One ppm is equivalent to 1 milligram of something per liter of water or 1 milligram of something per kilogram of soil.