Water Analysis Part 8 Flashcards
What does a hydroxide do to litmus?
Turns litmus blue
What does bromide form when mixed with silver nitrate?
Creamy precipitate
What does nitrate form when warmed with aluminium and sodium hydroxide?
Ammonia smell, turns litmus blue
What does chloride form when mixed with silver nitrate?
White precipitate
What does sulphate form when mixed with barium chloride and nitric acid?
White precipitate
What does a phosphate form when mixed with ammonium molybdate?
Yellow precipitate
What does a carbonate form when mixed with hydrochloric acid?
Effervescence occurs, gas turns limewater milky
What does iron (ii) form when mixed with K3FeCN6?
Dark blue precipitate
What does an iodide form when mixed with silver nitrate and ammonia?
Cloudy yellow precipitate
What can chemical tests be split into?
General tests or specific tests
What do general tests help you to identify?
The nature of the chemical, whether it is an acid, alkali, soluble or ionic
What do specific tests identify?
The particles in a substance
What is a precipitate?
An insoluble solid that forms during an aqueous reaction
What is the WQI?
Water quality index, which uses a series of tests to determine a stream’s water quality and the overall health of the stream
What are the ranges of the water quality index ratings?
Very Poor = 0-25 Poor = 25-50 Medium = 50-70 Good = 70-90 Excellent = 90-100
What are the factors which affect water temperature?
Air temperature, amount of shade, soil erosion, turbidity and thermal pollution
What are the effects of water temperature?
Solubility of dissolved oxygen, rate of plant growth, metabolic rate of organisms and resistance in organisms
In Victoria, what is the temperature range of water?
4°C in winter to above 25°C in summer
What are the factors which affect pH levels of water?
Acidic rainfall, algal blooms, releases from industrial processes and level of hard-water minerals
What is the pH value of streams and lakes usually between?
pH 7-8
What is the pH range acceptable for most drinking water standards?
pH 6.5-8.5
What pH range does rainfall generally have?
Between 5-6.5 pH
What is the pH range which is optimal for most organisms?
6.5-8.2 pH
