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A SIMPLE METHOD FOR THE DETECTION OF SOLUBLE BICARBONATES ANANTA GOPAL LAHlRI Burdwan Raj College, Burdwan, West Bengal, India
SOLUBLE bicarbonates can be detected in the presence of normal carbonates by using a suspension of yellow mercuric oxide in saturated sodium chloride solution. Using reagent grade chemicals the test is performed as follow^: id about 0.1 g. of yellow mercuric oxide to a test tube containing 10 ml. of distilled water. Shake the tube well. Add 5 g. of sodium chloride. Stopper the test tube and shake well for one minute. Alternately, add NaHCOs or any dilute acid and shake the test tube, until a faint yellow suspension
of HgO remains. Add the sample t o be tested, stopper, and shake thoroughly. I n the presence of bicarbonates the yellow color will disappear within two minutes as shown bv the following eauations:
-
H20
+ HgO + 2NaCl % HgCll + 2NaOH
NaOH
+ NaHCOa
-
NalCOa
+ HBO
As little as 0.002 g. of NaHC03 can be detected. Any acid compound which will react with NaOH will interfere with this test.
JOURNAL OF CHEMICAL EDUCATION
