A balloon expands as it fills with air. Which statement explains what happens to the internal pressure? A)The observed pressure is increasing as the collisions of gas molecules increase.
B)The observed pressure is decreasing as the collisions of gas molecules increase.
C)The observed pressure is decreasing as the collisions of gas molecules decrease.
D)The observed pressure is increasing as the collisions of gas molecules decrease.

For a research project, a student decided to test the effect of the lead(ii) ion (pb2+) on the ability of salmon eggs to hatch. this ion was obtainable from the water‐soluble salt, lead(ii) nitrate, which the student decided to make by the following reaction. pbo(s) + 2 hno3(aq) → pb(no3)2(aq) + h2o losses of product for various reasons were expected, and a yield of 86.0% was expected. in order to have 5.00 g of product at this yield, how many grams of pbo should be reacted? (assume that sufficient nitric acid, hno3, would be used.)