how to conduct a quantitive test of water hardness (1 Viewer)

[2006hsc]

how would u do a test for quantitive analysis of water hardness?

i heard finding the concentration of calcium but how would i go about doing that?

sorry for lots of question in the forum..

 

[angmor]

use something that precipitates calcium. qualitatively i think you can try and lather soap with water, if a scum forms then the water is hard

 

[Riviet]

how would u do a test for quantitive analysis of water hardness?

Water is hard mainly due to the prescence of significant concentrations of calcium and magnesium ions in the sample. You can measure the concentration of these using methods including those mentioned below or use a simple quantitative test for hardness by putting the sample(s) in separate beakers, give them a vigorous shake and observe the degree of lather formed in the sample.

i heard finding the concentration of calcium but how would i go about doing that?

3 possible (not the only) ways:
1) electrical conductivity can be used to measure the concentration of dissolved solids present as ions (salinity). The more dissolved salts (ions), the higher the conductivity.

2) AAS can be used and is extremely accurate.

3) Ion-selective electrodes (ISE) measure the concentration of any specific ion. The change in electrode voltage between a reference electrode and the indicator electrode is related to the concentration of the specific ion being measured.

 

[vanush]

You need to titrate with EDTA to find the number of moles of calcium, then you can find the mass of CaCO3.