Patrick did an experiment to study the solubility of two substances. He poured 100 mL of water at 20 °C into each of two beakers
labeled A and B. He put 60 g of Substance A in the beaker labeled A and 60 g of Substance B in the beaker labeled B. The solution in both beakers was stirred for 1 minute. The amount of substance left undissolved in the beakers was weighed. The experiment was repeated for different temperatures of water and the observations were recorded as shown. Experimental Observations
Substance Mass of Undissolved Substance at Different Temperatures (gram)
20 °C 40 °C 60 °C 80 °C
A 18 14 10 5
B 60 60 60 60
Part 1: Which, if any, substance is soluble in water?
Part 2: Explain how the data helped you determine solubility for both substances for temperatures 20 °C to 80 °C. (8 points)
A graph of the amount of solute dissolved againsttemperature helped to determine solubility for both substances for temperatures 20 °C to 80 °C.
<h3>What is the solubility of a substance?</h3>
The solubility of a substance of substance is the amount of that substance that dissolves in a given volume of solution or solvent.
The solubility of substances vary from one substance to another,
Some factors that affect the solubility of substances include:
temperature - the solubility of solids generally increases with temperature while the solubility of gases decrease with temperature and vice versa
pressure - the solubility of gases increase with increase in pressure and vice versa
nature of substance -some solutes generally have higher solubilities than others in a given solvent.
nature of solvent - based on the principle of like dissolves like, polar solutes dissolve in polar solvents whereas non-polar solute dissolve better in non-polar solvents.
The area of the brain that the nurse would be concerned about when finding to a woman who explain that she has been very unsteady and has difficulty in maintaining balance is cerebellum. Cerebellum is responsible in coordinate voluntary movement
Genetic variations that alter gene activity or protein function can introduce different traits in an organism. If a trait is advantageous and helps the individual survive and reproduce, the genetic variation is more likely to be passed to the next generation (a process known as natural selection)
Excreting urea helps in maintaining internal homeostasis by retaining water.
The mammals like humans excrete urea, while reptiles and birds, and some terrestrial invertebrates generate uric acid as waste. Generating uric acid in place of urea is beneficial as it is less toxic and diminishes water loss and the subsequent requirement for water.
This retention of water helps birds and reptiles to sustain internal homeostasis mainly in hot weather.
