An amphoteric salt is one that contains an anion that can act as either an acid or a base in water. baking soda, nahco3, is an example. by combining the ionization and hydrolysis reactions of the anion, you get the principle reaction that occurs when this salt is dissolved in water. 2hco−3(aq)↽−−⇀co2−3(aq)+h2co3(aq) 2 hco 3 − ( aq ) ↽ − − ⇀ co 3 2 − ( aq ) + h 2 co 3 ( aq ) the ph for such a solution is given by ph=pka1+pka22 ph = p k a 1 + p k a 2 2 where ka1 k a 1 and ka2 k a 2 are the ionization constants of the acid (in this case, h2co3). note that the ph of the solution is independent of the salt concentration. calculate the ph of a nahco3 solution.

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

Which of the following is true for the actual yield of a reaction? it is always calculated as a ratio. it is the yield from the excess reactant. it is the yield from the limiting reactant. it is always less than the theoretical yield.

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?