Question

Identify the molecule containing the least oxygen atoms. A) 12.044 × 10^23 molecules of CO2. B) 12 g of O3. C) 0.1 mol of V2O5. D)10 mL of H2O.

Answer 1

Answer:

C. 0.1 mol of V₂O₅

Explanation:

Number of moles of oxygen atoms present in each molecule is derived as follows:

A. Number of molecules of CO₂ in 12.044 * 10²³ molecules of CO₂ = 12.044 * 10²³/6.022 * 10²³ = 2 moles of CO₂ molecules

Each molecule of CO₂ contains 2 atoms of oxygen. Therefore, number of moles of oxygen atom present in 2 molecules of CO₂ = 2 * 2 moles of oxygen atoms = 4 moles of oxygen atoms.

B. Number of moles of O₃ molecules in 12g of O₃ = mass of O₃/molar mass of O₃

molar mass of O₃ = 48 g/mol

Number of  moles of O₃ molecules = 12/48 = 0.25 moles of O₃

There are 3 atoms of oxygen in a molecule of O₃, therefore number of moles of oxygen atoms present in 12 g of O₃ = 3 * 0.25 = 0.75 moles of oxygen atoms

C. There are 5 oxygen atoms in a molecule of V₂O₅

0.1 mol of V₂O₅ contains 0.1 * 5 moles of oxygen atoms = 0.5 moles of oxygen atoms.

D. mass of 10 mL of H₂O = 10 g since the density of H₂O = 1 g/mL

molar mass of H₂O = 18.0 g/mol

Number of moles of H₂O in 10 g of H₂O = 10/18 = 0.56 moles

There are 1 atom of oxygen in a molecule of H₂O, therefore, number of moles of oxygen present in 10 g of H₂O = 0.56 * 1 = 0.56 moles of oxygen atoms

Therefore, 0.1 mole of V₂O₅ contains the least number of oxygen atoms.