Define
Parts per million

RH_2 (ion exchange resin) can replace Ca^(2+) ions in hard water as RH_2+Ca^(2+)rarr RCa+2H^+ . If 1 L of hard water after passing through RH_2 has pH=3 then hardness in parts per million of Ca^(2+) is :

If hardness of water sample is 200 parts per million , Calculate the mass ratio of CaCO3 to water is:

A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows : For how many days, was the concentra-tion ofsulphur dioxide more than 0.11 parts per million.

A study was conducted to find out the concentration of sulphur dioxide in the air in parts per million (ppm) of a certain city. The data obtained for 30 days is as follows : Make a grouped frequency distribution table for this data with class intervals as 0.00 - 0.04, 0.04 -0.08 and so on.

Define a ray.

Define Trees.

Define BOD .