Tell how you could distinguish chemically between the follow

Tell how you could distinguish chemically between the following pairs of sub- stances (in separate test tubes) in one or two steps. In each case, tell what you would observe. Include equations for reactions occurring. 4. a) NaCl and NaNO, solutions

Solution

Solution:

4)

a) NaCl and NaNO₃:

If we add AgNO₃ to the test tube containing NaCl solution we will get white precipitate of AgCl.

Similarly the same amount of AgNO₃ will not give any precipitate with NaNO₃. So by adding AgNO₃ solution, we can easily distinguish NaCl solution from NaNO₃ solution.

b) KI and Na₂SO₄:

Addition of AgNO₃ solution to the KI solution will give bright yellow solid of AgI, while the addition of AgNO₃ to Na₂SO₄ solution will give white precipitate of Ag₂SO₄ solid.

c) KNO₃ and K₃PO₄:

Addition of AgNO₃ solution to the K₃PO₄ solution will give yellow solid of Ag₃PO₄, while the addition of AgNO₃ to KNO₃ will not give any precipitate.

d) BaCO₃ and Ba₃(PO₄)₂:

Addition of HCl solution to the BaCO₃ solid will give BaCl₂ solution with the evolution of CO₂ gas (we will find the gas in the form of bubbles).

BaCO₃ + 2HCl BaCl₂(aq)+H₂O(l) + CO₂(g)

While the addition of same amount of HCl solution to Ba₃(PO₄)₂ will not produce any bubbles.