Consider the statements about the borax bead test: (i) a copper salt gives a blue bead in the oxidising flame; (ii) a chromium salt gives a green bead; (iii) a manganese salt gives a violet bead in the oxidising flame; (iv) a cobalt salt gives a pink bead; (v) the coloured bead is a metal metaborate formed from the metal oxide and $B X_{2} O X_{3}$ . How many statements are correct?

Answer: A

Statements (i), (ii), (iii) and (v) are correct. Cobalt gives a deep blue bead as

Co (BO X_{2}) X_{2}

, so (iv) is wrong. Hence four statements are correct.