Three numbered test tubes contain solutions of sodium chloride, sodium carbonate, and sodium hydroxide

| September 11, 2021 | education

Three numbered test tubes contain solutions of sodium chloride, sodium carbonate, and sodium hydroxide. How to determine the contents of each tube? Confirm the answer with the equations of reactions in molecular and ionic forms.

1) Determine sodium chloride in the test tube, for this we add silver nitrate to the test tube, as a result, a white curdled precipitate of silver chloride is formed. We write down the equation of reactions.
NaCl + AgNO3 = AgCl + NaNO3;
Na (+) + Cl (-) + Ag (+) + NO3 (-) = AgCl + Na (+) + NO3 (-);
Ag (+) + Cl (-) = AgCl.

2) Determine sodium carbonate in a test tube. To do this, add hydrochloric acid, as a result, the formation of carbon dioxide occurs, as seen by the release of gas bubbles.
Na2CO3 + 2HCl = 2NaCl + CO2 + H2O;
2Na (+) + CO3 (-2) + 2H (+) + 2Cl (-) = 2Na (+) + 2Cl (-) + CO2 + H2O;
CO3 (-2) + 2H (+) = CO2 + H2O.

3) NaOH – determined by the color of the indicator, in an alkaline medium litmus – blue, phenolphthalein – raspberry, methyl orange – yellow.



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