Determine Total Suspended/Dissolved Solids (Exam Q)

Question 1

Describe how to determine by filtration the total suspended solids
(6)

Answer 1

Fill volumetric flask to the mark with water sample

Find the mass of a filter paper using a laboratory balance

Filter the known quantity of water through the filter paper, retaining the filtered water,

Dry the filter paper - air dry - or warm oven

Find the new mass of the filter paper ( subtraction - find mass of suspended solids in that particular vol of water)

Express the mass in mg/L i.e. p.p.m

Question 2

Describe how to determine the total dissolved solids (expressed as p.p.m) in a sample of the filtered water
(6)

Answer 2

Filter water by evaporation

Find the mass of a clean, dry beaker

Using a graduated cylinder, place a known quantity of the filtered water in the beaker

Place the beaker on a hotplate/over bunsen burner and evaporate until dryness (dissolved solids remain)

Allow the beaker to cool and find new mass (by subtraction - dissolved solids from that particular volume of water remain)

Express your results in mg/L or p.p.m

Question 3

What is the most accurate way of measuring the pH of the water?

Answer 3

Using a pH sensor