How would I do this? “ A buffer solution contains 0.400 mol dm-3 benzoic acid ( C6H6COOH) and 0.200 mol dm-3 sodium benzonate (C6H6COOH-Na+) at 25 degrees Celsius, Ka for benzoic acid is 6.40 X 10-5 mol
Calculate the pH of the buffer 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.

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.