Ions which make water hard

The boiling of temporary hard water forms a layer of limescale. This may coat the heating element in kettles and irons, for example, making them less efficient. Limescale is unsightly and it clogs up hot water pipes and boilers.

Lassaigne's test for the detection of nitrogen fails in. In which of the following reactions, there is no change in valency? Redox Reactions. Questions from Hydrogen. Which of the following statements concerning protium deuterium and tritium is not true? An example of non-stoichiometric hydride is AMU Lux soap flakes are ideal for making liquid soap if you can source them.

They do not form a stable emulsion and precipitate out overnight. Note that most liquid hand washes are based on the same detergents as washing-up liquids and do not contain soap. To obtain soap solution from soap flakes, dissolve soap flakes or shavings from a bar of soap in ethanol — use IDA Industrial Denatured Alcohol. Do not dissolve in water. Procedure Set up eight labelled test tubes, each containing 1 cm depth of one of the following: distilled or deionised water sodium chloride solution calcium chloride solution magnesium chloride solution potassium nitrate solution sodium sulfate solution iron II sulfate solution magnesium sulfate solution Collect about 50 cm 3 of soap solution in a small beaker.

Use a dropping pipette to add a 1 cm depth of soap solution to each test tube. Stopper each tube in turn and shake vigorously. Note which tubes contain a foamy lather and which do not.

Try to work out which ions are preventing the lathering. Additional information This is a resource from the Practical Chemistry project , developed by the Nuffield Foundation and the Royal Society of Chemistry. Level years years. Use Practical experiments. Category Compounds and mixtures Ions. Describe the cycling of matter, including that of carbon and water, associating it with biological and atmospheric phenomena.

The water flows through a semi-permeable membrane , which allows the water molecules to pass while filtering out unwanted molecules. This procedure requires several steps and is not as common in the home as ion exchange. Magnetic water conditioning occurs when electromagnets are attached to water pipes.

These electromagnets create a strong magnetic field within the pipe, which keeps the hard water minerals from precipitating into the plumbing. This method has not been scientifically proven, and it is unknown if and how it actually works.