1.
As solids' temperature increases, solubility ___________.
Explanation
When the temperature of a solid increases, the kinetic energy of its particles also increases. This increased kinetic energy allows the particles to move more rapidly and collide with the solvent particles with greater force. As a result, more solute particles can break away from the solid and dissolve into the solvent, leading to an increase in solubility. Therefore, the correct answer is that solubility increases as the temperature of solids increases.
2.
As gas pressure increases, solubility ___________.
Explanation
As gas pressure increases, the solubility of the gas increases. This is because an increase in pressure allows more gas molecules to come into contact with the solvent, increasing the chances of them dissolving. Additionally, the increased pressure can also compress the gas molecules, forcing them closer together and making it easier for them to dissolve in the solvent. Therefore, an increase in gas pressure leads to an increase in solubility.
3.
As solids' pressure increases, solubility ___________.
Explanation
As solids' pressure increases, the solubility decreases. This can be explained by Le Chatelier's principle, which states that when a system at equilibrium is subjected to a stress, it will shift in a way that minimizes the effect of that stress. In this case, increasing the pressure on a solid-liquid system will cause the equilibrium to shift towards the solid phase, resulting in a decrease in solubility. This is because higher pressure favors the formation of a smaller volume phase, which is the solid in this case. Therefore, the solubility of the solid decreases as pressure increases.
4.
A polar molecule (like water) is more likely to dissolve in a ___________ solution.
Explanation
A polar molecule, like water, is more likely to dissolve in a polar or polarized solution because polar molecules have an uneven distribution of charge, with one end being slightly positive and the other end slightly negative. This polarity allows polar molecules to interact with other polar molecules or ions in a solution through attractive forces known as dipole-dipole interactions or hydrogen bonding. In a polarized solution, the solvent molecules have a strong dipole moment, enhancing the solubility of polar solutes.
5.
A non-polar molecule (like oil or hexide) is more likely to dissolve in a ___________ solution.
Explanation
A non-polar molecule is more likely to dissolve in a nonpolar solution because like dissolves like. Nonpolar molecules do not have a positive or negative charge and do not interact well with polar molecules. Nonpolar solvents, such as oil or hexane, have similar nonpolar characteristics and can effectively dissolve nonpolar molecules.
6.
When dissolving a compound such as sugar (glucose), the partially positive ends of the water molecule will attach to the __________ ends of the sugar molecule (C6H12O6), and vice versa.
Explanation
When dissolving a compound such as sugar (glucose), the partially positive ends of the water molecule will attach to the negative ends of the sugar molecule (C6H12O6), and vice versa. This is because water is a polar molecule, meaning it has a positive end (hydrogen) and a negative end (oxygen). The negative oxygen end of the water molecule will be attracted to the positive hydrogen ends of the sugar molecule, creating a bond and allowing the sugar to dissolve in water.
7.
Solubility describes the amount of ___________ that will dissolve in a given amount of solvent at a given temperature.
Explanation
Solubility describes the amount of solute that will dissolve in a given amount of solvent at a given temperature. This means that solubility refers to the ability of a substance (solute) to dissolve in a solvent, such as a solid dissolving in a liquid. The solute particles become dispersed and evenly distributed throughout the solvent, resulting in a homogeneous mixture.
8.
What is one way that dissolved oxygen does NOT get into water? (Hint: Think of the formulas for photosynthesis/respiration)
Correct Answer
C. Cellular respiration
Explanation
Cellular respiration is the process by which cells break down organic molecules to release energy. It occurs in living organisms and is the opposite of photosynthesis. During cellular respiration, oxygen is consumed and carbon dioxide is produced. Therefore, it does not contribute to the addition of dissolved oxygen into water.
9.
What is a way that dissolved oxygen can NOT affect aquatic life (aerobic and anaerobic)?
Correct Answer
D. Dissolved oxygen is essential for water; therefore, it will have no effect on aquatic life.
Explanation
Dissolved oxygen is crucial for aquatic life as it is required for respiration. When DO levels decrease, fish and other aerobic aquatic life struggle to obtain enough oxygen, leading to their death. Decreased DO levels also promote the growth of harmful bacteria, which can negatively impact aquatic life. Additionally, the increased bacteria can consume all the available oxygen, further affecting aerobic organisms. Therefore, the statement that dissolved oxygen has no effect on aquatic life is incorrect.
10.
Based on the results of the indicator tests below, what type of solution is this?
Red Litmus Paper - No color change
Blue Litmus Paper - Turned red
Phenolphthalein - No change
pH Paper - Yellow
Universal Indicator - Yellow
Correct Answer
C. Acid
Explanation
The indicator tests show that the solution caused the red litmus paper to turn red and the pH paper to turn yellow. These are both indicators of an acidic solution. Therefore, based on the results of the tests, the solution is classified as an acid.
11.
Based on the results of the indicator tests below, what type of solution is this?
Red Litmus Paper - No change
Blue Litmus Paper - No change
Phenolphthalein - No change
pH Paper - No change
Universal Indicator - No change
Correct Answer
B. Neutral
Explanation
The solution is determined to be neutral based on the results of all the indicator tests. The red litmus paper, blue litmus paper, phenolphthalein, pH paper, and universal indicator all showed no change in color or reaction, indicating that the solution is neither acidic nor basic. Therefore, the correct answer is neutral.
12.
Based on the results of the indicator tests below, what type of solution is this?
Red Litmus Paper - Turned blue
Blue Litmus Paper - No change
Phenolphthalein - Turned pink
pH Paper - Blue
Universal Indicator - Blue
Correct Answer
A. Base
Explanation
The indicator tests show that the solution turned blue with red litmus paper, turned pink with phenolphthalein, and turned blue with pH paper and universal indicator. These results indicate that the solution is basic in nature.
13.
In a neutralization reaction, an acid + base will yield
Correct Answer
D. H20 + a salt.
Explanation
In a neutralization reaction, an acid reacts with a base to form water and a salt. The water is formed by the combination of the hydrogen ions (H+) from the acid and the hydroxide ions (OH-) from the base. The salt is formed by the combination of the remaining ions from the acid and the base. Therefore, the correct answer is H20 + a salt.
14.
How much KN03 will dissolve in 100g of water at 50 degrees Celcius?
Correct Answer
A. 80g.
Explanation
At 50 degrees Celsius, the solubility of KNO3 in water is 80g. This means that at this temperature, 80g of KNO3 can completely dissolve in 100g of water.
15.
How much KN03 will dissolve in 140g of water at 50 degrees Celcius?
Correct Answer
D. 112g.
Explanation
Scale factor of 1.4