What mass of K2HPO4 (174.176 g/mol) should be used to make 100. mL of a buffer with a pH of 7.31, assuming the conjugate acid has a concentration of 0.10 M and ignoring activity considerations? (Note that pK2 for phsophoric acid is 7.199, and express your answer with 2 sig figs).

What is the theoretical yield of carbon dioxide? a)0.993 gb)2.98 gc)3.65 gd)8.93 g

The density of an unknown gas at 98°c and 740 mmhg is 2.50 g/l. what is the molar mass of the gas with work showed?

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution. calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.