A chemistry graduate student is given 500. mL of a 1.60 M hydrocyanic acid (HCN) solution. Hydrocyanic acid is a weak acid with K_a = 4.9 times 10^-10. What mass of KCN should the student dissolve in the HCN solution to turn it into a buffer with pH = 9.16? You may assume that the volume of the solution doesn't change when the KCN is dissolved in it. Be sure your answer has a unit symbol, and round to 2 significant digits.

In pqr m< p=60 m< q= 30 and m

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.

Jose and eric were given four samples in lab. the results of their analysis are shown in the table. based on the data they collected, which sample is most likely a metal?