Describe the effects of temperature and pressure on solubility. If you had used boiling water instead of lukewarm water, would your results have changed? If so, how?

The effect of temperature on solubility is that there's an increase in the solubility of the substance.

Based on the complete information, it should be noted that there's a direct proportional relationship, thereby an increase in temperature will lead to an increase in the solubility of substances in liquids.

Also, pressure does not affect solubility in liquids. Lastly, by using boiling water instead of lukewarm water, there will be an increase the kinetic energy of the solvent molecules and this leads to rapid dissolving of the solute molecules.

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Explanation:

The effect of temperature on solubility of liquid has a direct proportion relationship, hence increased temperature increases the solubility of substances in liquids.

Pressure does not affect solubility in liquids, but the effects can be seen in gases as a direct proportion relationship.

Using boiling water would change the result, increased temperature will increase the kinetic energy of the solvent molecules to break the solute molecules rapidly hence causing the solute molecules to dissolve rapidly

part 1: the half-life of the element is 22 years.

part 2: it will take 132.02 year for the sample to decay from 308.0 g to 4.8125 g.

explanation:

part 1: there are two ways to determine the half life time.

first way: the half life time can be determined directly from its definition as it is the time required for the sample to decay to its half concentration.

from the data the initial concentration was 45.0 g and decayed to its half value (22.5 g) in 22.0 years.

second way: the radio active decay is considered first order reaction so we can use the laws of first order reactions.

k = (1/t) ln (a/a-x), where k is the rate constant of the reaction,

t is the time of the reaction

a is the initial concentration of the reactant

a-x is the remaining concentration at time (t)

a = 45.0 g the initial concentration at t = 0 year.

at t = 22 year, a-x = 22.5 g

then k = (1/22 year) ln (45.0 g/ 22.5 g) = 0.0315 year-1.

the half-life time (t1/2) = ln 2/ k = 0.693/ k =0.693/ 0.0315 = 22 years.

part 2:

using the same law k = (1/t) ln (a/a-x),

using the given data; a = 308.0 g and a-x = 4.8125 g and the calculated k from the part 1 (k = 0.0315 year-1)

t = (1/k) ln (a/a-x) = (1/0.0315) ln (308.0/ 4.8125) = 132.02 years