Calculate mass of sodium which contains same number of atoms as are present in 4g of calcium (Atomic weight Na = 23, atomic weight Ca = 40)

Explanation

To solve this problem, we begin by determining the number of atoms in 4g of calcium. Since 1 mole of calcium (40g) contains Avogadro's number of atoms (6.02 x 1023), 1 gram of calcium contains (6.02 x 1023)/40 atoms. Therefore, 4g of calcium contains 4 x (6.02 x 1023)/40 = 6.02 x 1022 atoms.Next, we need to find the mass of sodium that would contain this same number of atoms. Since 1 mole of sodium (23g) also contains Avogadro's number of atoms, the mass of sodium required is (23/6.02 x 1023) x 6.02 x 1022 atoms = 2.3g. Thus, the mass of sodium which contains the same number of atoms as are present in 4g of calcium is 2.3g.The other options are incorrect because they either miscalculate the relationship between the atomic masses or do not apply the stoichiometry needed to equate the number of atoms correctly.