1.
A mixture that contains a small amount of undissolved particles that do not settle out and will scatter light is called a _____.
Correct Answer
A. Colloid
Explanation
A colloid is a mixture that contains small undissolved particles that do not settle out and will scatter light. Unlike a solution, where the particles are evenly distributed and do not scatter light, a colloid has particles that are larger and can scatter light, making the mixture appear cloudy or opaque. Therefore, a colloid is the correct answer to describe a mixture with undissolved particles that scatter light.
2.
Select all the choices below that are considered a colloid.
Correct Answer(s)
A. Milk
B. Gelatin
D. Fog
Explanation
Milk, gelatin, and fog are considered colloids because they all exhibit the properties of a colloid. A colloid is a mixture where one substance is dispersed evenly throughout another substance, creating a stable suspension. In the case of milk, it is a colloid because fat globules are dispersed throughout the water. Gelatin forms a colloid when it is mixed with water, creating a gel-like substance. Fog is also a colloid because tiny water droplets are suspended in the air, creating a cloudy appearance. Water, on the other hand, is not considered a colloid as it does not have dispersed particles within it.
3.
A mixture in which particles can be seen and easily separated by settling and filtration is a _____
Correct Answer
A. Suspension
Explanation
A suspension is a mixture in which particles are visible and can be separated by settling and filtration. In a suspension, the particles are larger and do not dissolve in the solvent. They remain suspended in the solvent and can settle down over time. This allows for easy separation of the particles from the solvent by allowing them to settle and then filtering them out. Therefore, a suspension is the correct answer for a mixture in which particles can be seen and easily separated by settling and filtration.
4.
Solutes lower the freezing point of water by___________
Correct Answer
C. Making it harder for water to form crystals
Explanation
Solutes lower the freezing point of water by making it harder for water to form crystals. When solutes are dissolved in water, they disrupt the formation of the regular crystal lattice structure that occurs during freezing. This disruption makes it more difficult for water molecules to arrange themselves into a solid crystal structure, thus lowering the freezing point of the solution.
5.
A polar solvent will most likely dissolve __________.
Correct Answer
B. Polar solutes
Explanation
A polar solvent will most likely dissolve polar solutes. This is because polar solvents have a positive and negative end, which allows them to interact with other polar molecules. When a polar solute is introduced to a polar solvent, the positive and negative ends of the solvent attract the corresponding charges on the solute, causing the solute to dissolve. On the other hand, nonpolar solutes do not have charges that can interact with the polar solvent, so they are less likely to dissolve in a polar solvent.
6.
A small beaker contains 50 ml of water at 20 degrees Celsius. If three sugar cubes are placed in the beaker, they will eventually dissolve. Which action would speed up the rate at which the sugar cubes dissolve the fastest?
Correct Answer
D. Heat and stir the contents of the beaker
Explanation
Heating and stirring the contents of the beaker would speed up the rate at which the sugar cubes dissolve the fastest. Heating the water increases the kinetic energy of the water molecules, causing them to move faster and collide with the sugar cubes more frequently, leading to faster dissolution. Stirring the mixture helps to evenly distribute the heat and maintain a constant flow of fresh water molecules to the surface of the sugar cubes, further enhancing the dissolution process.
7.
Sugar water is an example of _____
Correct Answer
B. Solution
Explanation
Sugar water is an example of a solution because it is a homogeneous mixture where sugar molecules are evenly distributed and dissolved in water. In a solution, the solute (in this case, sugar) is dissolved in the solvent (water) to form a single phase. Unlike suspensions or colloids, solutions do not settle or scatter light, making sugar water a clear and transparent mixture.
8.
A solution in which more solute may be dissolved at a given temperature is a _______
Correct Answer
B. Unsaturated solution
Explanation
An unsaturated solution is a solution in which more solute can be dissolved at a given temperature. In other words, it has not reached its maximum capacity to dissolve solute. This means that additional solute can be added to the solution and it will continue to dissolve.
9.
The substance found in a solution in the smallest amount is a called a _____________
Correct Answer
D. Solute
Explanation
The substance found in a solution in the smallest amount is called a solute. In a solution, the solute is the component that is dissolved in the solvent. It is typically present in a lesser quantity compared to the solvent. The solute can be a solid, liquid, or gas, and it disperses evenly throughout the solvent to form a homogeneous mixture.
10.
The measure of how much solute can dissolve in a solvent at a given temperature is called ____.
Correct Answer
B. Solubility
Explanation
Solubility refers to the measure of how much solute can dissolve in a solvent at a given temperature. It is a characteristic property of a substance and is influenced by factors such as temperature and pressure. The solubility of a substance determines its ability to form a homogeneous solution with a solvent. The saturation point refers to the point at which no more solute can be dissolved in the solvent at a given temperature and pressure. Concentration, on the other hand, refers to the amount of solute present in a given amount of solvent or solution.
11.
The three factors that affect solubility are ______.
Correct Answer
B. Pressure, surface area, temperature
Explanation
The solubility of a substance is affected by pressure, surface area, and temperature. Increasing the pressure on a gas or a solid can increase its solubility in a liquid. Increasing the surface area of a solid can also increase its solubility because it exposes more of the solid to the solvent. Temperature also plays a role in solubility, as increasing the temperature can often increase the solubility of a solid in a liquid. Therefore, the correct answer is pressure, surface area, and temperature.
12.
If you add a solute to a dilute solution, the solution becomes more
Correct Answer
B. Concentrated
Explanation
When a solute is added to a dilute solution, the concentration of the solute in the solution increases. This means that there is a higher amount of solute particles present in the solution compared to the solvent. Therefore, the correct answer is "Concentrated".
13.
Select all the choices below that are considered a suspension.
Correct Answer(s)
A. Italian salad dressing
B. Sandy water
D. Some Liquid Medicines
Explanation
A suspension is a heterogeneous mixture in which solid particles are dispersed in a liquid or gas medium. Italian salad dressing can be considered a suspension because it contains solid particles such as herbs and spices dispersed in a liquid medium. Sandy water is also a suspension as it contains solid particles of sand dispersed in water. Some liquid medicines can also be suspensions, as they may contain solid particles of medication dispersed in a liquid medium. Windex, on the other hand, is not a suspension but a solution, as it is a homogeneous mixture of various chemicals dissolved in a liquid medium.
14.
Select all the choices below that are considered a solution.
Correct Answer(s)
A. Food color in water
B. Windex
D. Tap Water
Explanation
Tap water, food color in water, and Windex are considered solutions because they are all homogeneous mixtures where one substance (the solute) is dissolved in another substance (the solvent) to form a uniform mixture. Tap water is a solution of various dissolved minerals and gases in water. Food color in water is a solution of food coloring molecules dissolved in water. Windex is a solution of ammonia, detergents, and other cleaning agents dissolved in water. Mayonnaise, on the other hand, is not a solution but an emulsion, where small droplets of one liquid (oil) are dispersed in another liquid (water) with the help of an emulsifying agent.
15.
How does a solute, when added to a solvent, affect the freezing point of the solvent
Correct Answer
B. Lowers the freezing point
Explanation
When a solute is added to a solvent, it lowers the freezing point of the solvent. This is because the solute particles disrupt the crystal lattice formation of the solvent, making it more difficult for the solvent molecules to arrange themselves in an orderly manner and freeze. As a result, the solvent requires a lower temperature to freeze, causing the freezing point to decrease. This phenomenon is known as freezing point depression and is commonly observed in solutions such as antifreeze, where the addition of solutes allows the liquid to remain in a liquid state at lower temperatures.
16.
How does a scientist measure concentration?
Correct Answer
A. The measure of how much solute can be dissolved in a solvent at a given temperature
Explanation
A scientist measures concentration by determining the amount of solute that can be dissolved in a solvent at a specific temperature. This is done by adding the solute to the solvent and observing how much of it dissolves. The concentration is then calculated based on the ratio of the amount of solute to the amount of solvent.
17.
As the pressure of a liquid decreases
Correct Answer
A. Less gas can be dissolved in the liquid
Explanation
When the pressure of a liquid decreases, the solubility of gases in the liquid also decreases. This is because the solubility of gases is directly proportional to the pressure. When the pressure is reduced, the gas molecules have less force pushing them into the liquid, causing them to escape and reduce the amount of gas that can be dissolved. Therefore, less gas can be dissolved in the liquid when the pressure decreases.
18.
A mixture in which no more solute can be dissolved is called
Correct Answer
A. Saturated
Explanation
A mixture in which no more solute can be dissolved is called saturated. In a saturated solution, the solvent has reached its maximum capacity to dissolve the solute, resulting in a state of equilibrium where the rate of dissolution equals the rate of crystallization. Any additional solute added to a saturated solution will not dissolve and will instead settle at the bottom. This is different from unsaturated solutions, where more solute can still be dissolved, and supersaturated solutions, which contain more solute than theoretically possible at a given temperature.
19.
A solution that has more dissolved solute than is predicted by its solubility at a given temperature is called
Correct Answer
B. Supersaturated
Explanation
Supersaturated refers to a solution that contains more dissolved solute than what is normally expected at a given temperature. This can occur when a solution is heated and then slowly cooled, allowing more solute to dissolve than would be possible under normal conditions. As a result, the solution becomes unstable and can precipitate out excess solute if disturbed.
20.
The concentration of a solution is measured by....
Correct Answer
A. Comparing the amount of solute to the amount of solvent
Explanation
The concentration of a solution is determined by comparing the amount of solute (the substance being dissolved) to the amount of solvent (the substance doing the dissolving). This ratio helps to quantify the amount of solute present in a given volume of solution. By comparing the amount of solute to the amount of solvent, the concentration of the solution can be accurately measured.
21.
A scientist can change the concentration of a solution
Correct Answer
C. By either adding more solute or changing the amount of solvent
Explanation
A scientist can change the concentration of a solution by either adding more solute or changing the amount of solvent. Adding more solute will increase the concentration because there will be a higher amount of solute particles in the same volume of solvent. On the other hand, changing the amount of solvent will also affect the concentration. If the volume of solvent is decreased, the concentration will increase because the same amount of solute is now dissolved in a smaller volume. Conversely, if the volume of solvent is increased, the concentration will decrease because the solute is now spread out in a larger volume of solvent.
22.
The higher the pressure of the gas over the solvent, the more gas can be dissolved.
Correct Answer
A. True
Explanation
The statement is true because according to Henry's law, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the liquid. This means that as the pressure of the gas increases, more gas molecules are forced into the solvent, leading to an increase in the amount of gas that can be dissolved. Conversely, if the pressure decreases, less gas can be dissolved in the solvent.
23.
The expression "like dissolves like" means
Correct Answer
B. Polar dissolves polar
Explanation
The statement "like dissolves like" refers to the principle that substances with similar polarity or solubility properties tend to dissolve in each other. In this case, the answer "Polar dissolves polar" is correct because polar substances, which have a separation of positive and negative charges, are more likely to dissolve in other polar substances. This is due to the attraction between the positive and negative charges of the molecules, allowing them to mix and form a homogeneous solution.
24.
In a solution created from dissolving an ionic compound in water, which of the following is true?
Correct Answer
A. The ionic compound is broken down into ions
Explanation
When an ionic compound is dissolved in water, it undergoes a process called dissociation, where the compound breaks down into its constituent ions. This occurs because water molecules surround the ions, attracting them and pulling them apart from each other. As a result, the ionic compound is broken down into its positively charged cations and negatively charged anions, which are then dispersed throughout the solution. Therefore, the statement "The ionic compound is broken down into ions" is true.
25.
In a solution created by dissolving a molecular solid in water which is true?
Correct Answer
B. The slightly polar molecules are attracted to and dissolved by the polar water molecules
Explanation
In a solution created by dissolving a molecular solid in water, the slightly polar molecules are attracted to and dissolved by the polar water molecules. This is because water is a polar solvent, meaning it has a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom. The slightly polar molecules in the solid are also attracted to these charges and can form hydrogen bonds with the water molecules, allowing them to dissolve and become evenly distributed throughout the solution.
26.
Solutes affect the boiling point of a solution by....
Correct Answer
B. Raising the boiling point
Explanation
Solutes affect the boiling point of a solution by raising it. When a solute is added to a solvent, it disrupts the intermolecular forces between the solvent molecules, making it harder for them to escape as vapor. This results in an increase in the boiling point of the solution compared to the pure solvent. The presence of solutes increases the boiling point because it requires more energy to overcome the stronger intermolecular forces and convert the liquid into vapor.
27.
An example of a solution that contains a gas solute in gas solvent is _____________.
Correct Answer
B. Air
Explanation
Air is an example of a solution that contains a gas solute in gas solvent. Air is a mixture of various gases, with nitrogen being the most abundant gas, followed by oxygen. Other gases such as carbon dioxide, helium, and argon are also present in smaller amounts. In this case, the gases present in air act as the solute, while the overall mixture of gases acts as the solvent. Therefore, air can be considered as a solution that contains a gas solute in gas solvent.
28.
An example of solution that contains a solid solute in liquid solvent is
Correct Answer
C. Ocean Water
Explanation
Ocean water is an example of a solution that contains a solid solute in a liquid solvent. In this case, the solid solute is the various salts and minerals that are dissolved in the liquid solvent, which is water. The ocean water contains a mixture of different salts such as sodium chloride, magnesium chloride, and calcium chloride, among others. These salts dissolve in the water, forming a homogeneous solution.
29.
A solution with an ionic solute dissolved in it will differ from a solution with a molecular solute dissolved in it because _____
Correct Answer
A. Ionic solutions will conduct electricity
Explanation
Ionic solutions will conduct electricity because they contain ions that are free to move and carry an electric charge. When an electric current is applied to the solution, the ions will migrate towards the oppositely charged electrode, allowing the flow of electricity. In contrast, molecular solutes do not dissociate into ions and therefore do not conduct electricity.