# GATE Questions & Answers of Quality standards

## What is the Weightage of Quality standards in GATE Exam?

Total 6 Questions have been asked from Quality standards topic of Water and Waste Water subject in previous GATE papers. Average marks 1.67.

A water sample analysis data is given below.

 Ion Concentration, mg/L Atomic Weight $\style{font-family:'Times New Roman'}{\mathrm{ca}^{2+}}$ 60 40 $\style{font-family:'Times New Roman'}{\mathrm{Mg}^{2+}}$ 30 24.31 $\style{font-family:'Times New Roman'}{{\mathrm{HCO}}_3-}$ 400 61

The carbonate hardness (expressed as mg/L of CaCO3, up to one decimal place) for the water sample is ______

The hardness of a ground water sample was found to be 420 mg/L as CaCO3. A softener containing ion exchange resins was installed to reduce the total hardness to 75 mg/L as CaCO3 before supplying to 4 households. Each household gets treated water at a rate of 540 L/day. If the efficiency of the softener is 100%, the bypass flow rate (expressed in L/day) is _________

A sample of water has been analyzed for common ions and results are presented in the form of a bar diagram as shown.;

The non-carbonate hardness (expressed in mg/L as CaCO3) of the sample is

A water sample has a pH of 9.25. The concentration of hydroxyl ions in the water sample is