Referring to an activity series, which of the following combinations of reactants would not produce a successful single-replacement reaction?
a) li + nacl
b) cu + cacl2
c) mg + fecl3
d) ca + alcl3

Cu + CaCl₂ would not produce a successful single replacement reaction.

Explanation:

Activity series is constructed on the basis of tendency of an element to lose or gain electrons.

An element which can reduced other can replace it from the ionic solution.

More the reactivity of the metal more the tendency to replace others.

The tendency is measured in terms of standard reduction potential, lower the reduction potential more the tendency to replace other (a better reducing agetn).

A) Li + NaCl, here Li is a better reducing agent so can replace sodium.

B) Cu + CaCl₂, here Ca is a better reducing agent so copper cannot replace calcium.

C) Mg + FeCl₃, Mg is a better reducing agent so can replace iron.

D) Ca + FeCl₃, Ca Mg is a better reducing agent so can replace iron.

a saline water is fed to a reverse osmosis unit at flow rate o rotameter connected to reject (retentate) line reads 8 installed in reject and permeate line reads 15.2 milli siemens/cm and 300 micro siemens/com respectively.