If the molar mass of X(HCO3)2 is 162 g mol−1, determine the relative atomic mass of X. [H = 1.0, C = 12.0, 0 = 16.0]

The molar mass of X(HCO3)2 can be calculated by adding up the atomic masses of all the atoms in one mole of the compound. One mole of X(HCO3)2 contains: - 2 moles of hydrogen (2 x 1.0 = 2.0) - 2 moles of carbon (2 x 12.0 = 24.0) - 6 moles of oxygen (6 x 16.0 = 96.0) - 1 mole of X The total molar mass is then: 2.0 + 24.0 + 96.0 + m(X) = 162 g/mol Solving for m(X), we get: m(X) = 162 g/mol - 2.0 - 24.0 - 96.0 m(X) = 40 g/mol Therefore, the relative atomic mass of X is 40, which corresponds to the atomic mass of the element with the symbol Ca (calcium). Therefore, option A is the correct answer.