Recent questions tagged principles-of-water-chemistry

Chlorine is most effective as a water disinfectant at a $\text{pH}$ of _____________.$6$ $8$$10$$12$

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$-3,+3$,...

What is the $\text{pH}$ of a water sample having $\mathrm{H}^{+}$ concentration of $10$ $\mathrm{mg} / \mathrm{L}$?The atomic weight of $\mathrm{H}$ is $1 \mathrm{~g} / ...

A $200 \mathrm{~mL}$ sample of water has an initial $\mathrm{pH}=9$. In order to determine alkalinity, the sample was titrated using $0.02 \mathrm{~N} \mathrm{H}_2 \mathr...

In the context of water quality, which of the following is/are correct for the most probable number $\text{(MPN)}$ of a water sample?The estimated organisms are gram nega...

An underground hazardous waste storage tank is leaking. The contaminant concentration directly beneath the site is $0.5 \mathrm{mg} / \mathrm{L}$. The contaminant is trav...

Excess amount of solid calcium sulphate $\left(\mathrm{CaSO}_4\right)$ was added to a pure water sample $(\mathrm{pH}=7)$ so that some solids remain undissolved at the eq...

The molar concentrations $(M$, i.e. $m o l / L)$ of some ionic species in a water sample were estimated as follows:$\mathrm{Na}^{+}=0.25{\mathrm{M} ; \mathrm{Ca}^{2+}}^{2...

Specific conductance is used in water analysis to indirectly estimate dissolved solids. The measurements used in the method accounts forCations onlyAll ionsAnions onlyUn-...

Carbon dioxide is used in recarbonation process. A solution has $1 \mathrm{~mole} / \mathrm{L}$ supersaturated calcium carbonate. Estimated amount of carbon dioxide (in g...

A river water sample has $\mathrm{pH}$ of $4$ and suspended solids concentration of $100 \; \mathrm{mg} / \mathrm{L}$. If, alum is chosen as a coagulant, what will be the...

For effluents generated by a molasses based distillery and wood based pulp and paper industry, which of the following statement(s) is/are NOT correct?Both the effluents h...

The Henry's law constant of $\mathrm{CO}_{2}$ is $3.4 \times 10^{-2} \mathrm{M}$ per atm in neutral water at $25^{\circ} \mathrm{C}$. The dissolved $\mathrm{CO}_{2}$ (i.e...

A solution has $0.001$ mole/L zinc ions having $\mathrm{pH}$ of $6$. Solubility product of zinc hydroxide is given as $8 \times 10^{-18}(\mathrm{~mole} / \mathrm{L})^{3}$...

Clean water is passed through a bed of uniform spherical sand at a filtration velocity of $0.002 \mathrm{~m} / \mathrm{sec}$. The sand grains are $0.4 \mathrm{~mm}$ in di...