Borate ion (BO3³-) is treated with concentrated H2SO4 and heated, producing compound P which gives white fumes. In a separate experiment, the same borate ion is heated with concentrated H2SO4 in the presence of ethanol (C2H5OH), producing compound Q whose vapours can be ignited with a gree

Question

Borate ion (BO3³-) is treated with concentrated H2SO4 and heated, producing compound P which gives white fumes. In a separate experiment, the same borate ion is heated with concentrated H2SO4 in the presence of ethanol (C2H5OH), producing compound Q whose vapours can be ignited with a green-edged flame. Identify P and Q respectively.

Accepted Answer

P = H3BO3, Q = (C2H5O)3B. When BO3³- reacts with concentrated H2SO4, boric acid (H3BO3) is liberated; it sublimes as white fumes. When ethanol is also present, the H3BO3 formed immediately esterifies with ethanol to give triethyl borate (C2H5O)3B, which burns with a characteristic green-bordered flame — the standard test for boron compounds.

Solution

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