A standard solution is prepared by dissolving 5.30 g of sodium carbonate, Na2CO3, in 250 cm³ of distilled water in a volumetric flask. A 10.0 cm³ sample of this solution is removed by bulb pipette and diluted with water to the final volume of 0.100 dm³. Calculate the concentration, in mol dm-3, of the diluted solution.

Construct the hypothetical phase diagram for metals a and b between room temperature (20c) and 700c, given the following information: * the melting temperature of metal a is 480c. • the maximum solubility of b in a is 4 wt% b, which occurs at 420c. • the solubility of b in a at room temperature is 0 wt% b. • one eutectic occurs at 420c and 18 wt% b–82 wt% a. • a second eutectic occurs at 475c and 42 wt% b–58 wt% a. • the intermetallic compound ab exists at a composition of 30 wt% b–70 wt% a, and melts congruently at 525c.• the melting temperature of metal b is 600c. • the maximum solubility of a in b is 13 wt% a, which occurs at 475c. • the solubility of a in b at room temperature is 3 wt% a.

Compared with the freezing-point depression of a 0.01 m c6h12o6 solution, the freezing-point depression of a 0.01 m nacl solution is

Which factor is likely to impact the possible number of compounds ?