Asolution is prepared by dissolving 0.23 mol of hydrocyanic acid and 0.27 mol of sodium cyanide in water sufficient to yield 1.00 l of solution. the addition of 0.05 mol of hcl to this buffer solution causes the ph to drop slightly. the ph does not decrease drastically because the hcl reacts with the present in the buffer solution. the ka of hydrocyanic acid is 4.9 × 10-10.

Plz choose one of the compounds from the table and explain how you know the numbers of atoms in your formula. is it possible for two different compounds to be made from the exact same two elements? why or why not? with a limited number of elements (less than 120 are known), does this mean we also have a small number of compounds or do we have a large number of compounds in this world?

What is the volume occupied by 10.0 dm3 of gas at standard pressure after it has been compressedat constant temputure to 500.0 kpa?

State one important difference between a physical change and a chemical change?