6.
you decide it is necessary to conduct a second, a third, and even a fourth weighing of your
crucible at the end of the experiment. which of these weights is utilized to calculate the per-
centage of nahco3,? explain your answer fully.

Enough of a monoprotic weak acid is dissolved in water to produce a 0.0172 m solution. if the ph of the resulting solution is 2.39 at 20 °c, determine the pka for the acid.

How can you use chemical equations to predict the products of the reaction you can carry out?

3. how much energy in joules is required to evaporate .0005 kg of liquid ammonia to vapor at the same temperature? 4. how much energy ( in megajoules ) is given up by .75 kg of water at 0c when it freezes to form ice at 0c? 5. explain how heat works between and at critical temperatures?