Chemistry
An element X combines with oxygen to form an oxide X2O3. This oxide is a good conductor of electricity and can be reduced to its metal only by electrolysis.
(a) Write the equation for the reaction formed when the oxide (X2O3) combines with hydrochloric acid.
(b) How many valence electrons are present in the outermost shell of X?
(c) Will element X undergo oxidation or reduction?
Answer
Element X is a metal, and its oxide is X2O3 so X must have a valency of 3 (X3+). The oxide is a good conductor of electricity. Since it requires electrolysis to extract X, it must be a very reactive metal.
(a) The oxide (X2O3) is reacting with hydrochloric acid, so we can say the oxide is ionic and basic in nature. The reaction will give salt and water.
X2O3 + 6HCl ⟶ 2XCl3 + 3H2O
(b) Since X forms X3+, it must lose 3 electrons, meaning it has 3 valence electrons.
(c) To form X3+, element X must lose 3 electrons and loss of electron is oxidation.
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