GATE ES format:nat PYQs & Answers — Page 13

Questions 121–122 of 122. Imported answers require independent review unless marked reviewed.

Topic practice 122 questionsPage 13 of 13

Excess amount of solid calcium sulfate (CaSO₄) was added to a pure water sample (pH = 7) so that some solids remain undissolved at the equilibrium. The solubility product of CaSO₄ is 2×10⁻⁵ mol²/L². The molar concentration of SO₄²⁻ in this water sample at equilibrium will be ______ mol/L (rounded off to three decimal places).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A facultative pond system for sewage treatment consists of two ponds in series. The hydraulic retention time (HRT) of each pond is 6 days. The total BOD₅ reduction through the entire pond system is 90 %. If the ponds are considered to be completely mixed, then the rate constant describing the BOD₅ removal is ______ day⁻¹ (rounded off to two decimal points). Assume that the rate constant is same for both the ponds.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE ES format:nat PYQs

Question 54

Question 55