Chlorine gas used for disinfection combines with water to form hypochlorous acid (HOCl). The HOCl ionizes to form hypochlorite (OCl ) in a reversible reaction: HOCl H+ + OCl (k = 2.7 10 8 at 20 C) the equilibrium of which is governed by pH. the sum of HOCI and OCl is known as free chlorine residual and HOCl is the more effective disinfectant. The 90% fraction of HOCl in the free chlorine residual is available at a pH value.

Chlorine gas used for disinfection combines with water to form hypochl

1.	Chlorine gas used for disinfection combines with water to form hypochlorous acid (HOCl). The HOCl ionizes to form hypochlorite (OCl ) in a reversible reaction: HOCl H+ + OCl (k = 2.7 10 8 at 20 C) the equilibrium of which is governed by pH. the sum of HOCI and OCl is known as free chlorine residual and HOCl is the more effective disinfectant. The 90% fraction of HOCl in the free chlorine residual is available at a pH value.
A.	4.3
B.	6.6
C.	7.5
D.	9.4
Answer» E.

Discussion

No Comment Found

Related MCQs

A student began experiment for determination of 5-day, 20 C BOD on Monday. Since the 5th day fell on Saturday, the final DO readings were taken on next Monday. On calculation, BOD (i.e. 7 day, 20 C) was found to be 150 mg/L. What would be the 5-day, 20 C BOD (in mg/L)? Assume value of BOD rate constant (k) at standard temperature of 20 C as 0.23/day (base e).
Total hardness in mg/l as CaCO3 is
The results of analysis of a raw water sample are given below [2003, 1 marks] Turbidity:5 mg/LpH:7.4Fluorides:2.5 mg/LTotal Hardness:300 mg/LIron:3.0 mg/LMPN:50 per 100 mlFrom the data given above, it can be inferred that water needs removal of
Chlorine gas used for disinfection combines with water to form hypochlorous acid (HOCl). The HOCl ionizes to form hypochlorite (OCl ) in a reversible reaction: HOCl H+ + OCl (k = 2.7 10 8 at 20 C) the equilibrium of which is governed by pH. the sum of HOCI and OCl is known as free chlorine residual and HOCl is the more effective disinfectant. The 90% fraction of HOCl in the free chlorine residual is available at a pH value.
A water treatment plant is required to process 28800 m /d of raw water (density = 1000 kg/m , kinematic viscosity = 10 6 m /s). The rapid mixing tank imparts a velocity gradient of 900s 1 to blend 35 mg/l of alum with the flow for a detention time of 2 minutes. The power input (W) required for rapid mixing is
Anaerobically treated effluent has MPN of total coliform as 106 /100 ml. After chlorination, the MPN value declines to 10 /100 ml. The per cent removal (%R) and log removal (log R) of total coliform MPN is
The alkalinity and hardness of a water sample are 250 mg/l and 350 mg/l as CaCO3, respectively. The water has
A synthetic sample of water is prepared by adding 100 mg Kaolinite (a clay mineral), 200 mg glucose, 168 mg NaCl, 120 mg MgSO4 and 111 mg CaCl2 to 1 litre of pure water. The concentrations of total solids (TS) and fixed dissolved solids (FDS) respectively in the solution in mg/L are equal to
Ultimate BOD of a river water sample is 20 mg/L. BOD rate constant (natural log) is 0.15 day-1. The respective values of BOD (in%) exerted and remaining after 7 days are:
In disinfection, which of the following forms of chlorine is most effective in killing the pathogenic bacteria?

Discussion

No Comment Found

Related MCQs

Reply to Comment