1.
A solution in which no more material will dissolve is _____.
Correct Answer
A. Saturated
Explanation
A solution in which no more material will dissolve is saturated. In a saturated solution, the solvent has dissolved as much solute as it can at a given temperature and pressure. Any additional solute added will not dissolve and will remain as solid particles at the bottom of the container. This is because the solution has reached its maximum solubility limit.
2.
The material that seems to disappear in a solution is the _____.
Correct Answer
A. Solute
Explanation
The correct answer is solute. In a solution, the solute is the substance that gets dissolved and seems to disappear. It is usually present in a smaller amount compared to the solvent. The solvent, on the other hand, is the substance in which the solute dissolves and is usually present in a larger amount.
3.
If one lemonade mixture has twice as much water AND twice as much powder as the first, the solutions have the same
Correct Answer
A. Concentration
Explanation
If one lemonade mixture has twice as much water and twice as much powder as the first, it means that the ratio of water to powder is the same in both mixtures. Since concentration is defined as the amount of solute (powder) dissolved in a given amount of solvent (water), the concentration of both mixtures will be the same. Therefore, the correct answer is concentration.
4.
The solid form of a material that can be identified by it's properties such as shape and pattern is a _____.
Correct Answer
A. Crystal
Explanation
A crystal is the solid form of a material that has a specific shape and pattern. Crystals have a regular and repeating arrangement of atoms or molecules, which gives them their distinct properties. These properties, such as shape and pattern, can be used to identify and classify different types of crystals.
5.
To add water is to _____.
Correct Answer
A. Dilute
Explanation
To add water is to dilute. When water is added to a substance, it increases the volume of the mixture and reduces the concentration of the solute. This process is known as dilution.
6.
A new solid material formed as a result of a chemical reaction is a _____.
Correct Answer
A. Precipitate
Explanation
A new solid material formed as a result of a chemical reaction is called a precipitate. When two or more substances react chemically, they may form a solid product that is insoluble in the reaction mixture. This solid product, known as a precipitate, separates from the solution and can be observed as a solid material. Precipitates are often formed in reactions involving ions and can be identified by their distinct appearance and formation process.
7.
Water is the _____ in a salt-water solution.
Correct Answer
A. Solvent
Explanation
In a salt-water solution, water acts as the solvent. A solvent is a substance that dissolves another substance, called the solute, to form a solution. In this case, salt is the solute and water is the solvent. The water molecules surround and separate the ions of the salt, allowing them to dissolve and form a homogeneous mixture. Therefore, the correct answer is solvent.
8.
The only difference between a screen and filter paper is the size of the _____.
Correct Answer
A. Holes
Explanation
The correct answer is "holes". The explanation for this is that the only distinguishing factor between a screen and filter paper is the size of the holes. A screen typically has larger holes that allow larger particles to pass through, while filter paper has smaller holes that can trap smaller particles and allow only the liquid or solution to pass through. The size of the holes determines the effectiveness of the screen or filter paper in separating particles from a solution.
9.
The liquid that dissolves a solid material in a solution is called the _____.
Correct Answer
A. Solvent
Explanation
The liquid that dissolves a solid material in a solution is called the solvent. A solvent is a substance that has the ability to dissolve other substances, known as solutes, to form a homogeneous mixture. In a solution, the solvent is present in a larger amount compared to the solute. The solvent molecules surround and separate the solute particles, allowing them to disperse evenly throughout the solution. Examples of solvents include water, alcohol, and acetone.
10.
The amount of a substance that can be dissolved in a set amount of water is it's _____.
Correct Answer
A. Solubility
Explanation
Solubility refers to the maximum amount of a substance that can be dissolved in a given amount of water. It is a measure of how well a substance can dissolve in water. Concentration, on the other hand, refers to the amount of a substance present in a given volume of solution. Flavor and reactant are unrelated to the ability of a substance to dissolve in water.
11.
An explosion is an example of which of the signs of chemical reaction
Correct Answer
A. Heat release
Explanation
An explosion is an example of the sign of chemical reaction called "heat release" because during an explosion, a large amount of energy is released in the form of heat. This heat is generated by the rapid reaction between substances, causing them to break apart and form new compounds. The release of heat is often accompanied by a release of light and sound as well.
12.
What did the bags allow us to discover about our chemical reactions?
Correct Answer
A. How much gas was created
Explanation
The bags allowed us to discover how much gas was created during our chemical reactions. This implies that the bags were used to collect and measure the amount of gas produced. By analyzing the gas content, we could determine the extent of the reaction and its efficiency. The bags served as a means of quantifying the gas generated, providing valuable information about the reaction's progress and outcomes.
13.
I have a new white substance following a chemical reaction. How could I test for a characteristic to prove it is chalk?
Correct Answer
A. See if it reacts with vinegar
Explanation
To test if the substance is chalk, one can check if it reacts with vinegar. Chalk, which is primarily composed of calcium carbonate, will produce carbon dioxide gas when it reacts with vinegar due to the acid-base reaction. This can be observed by the formation of bubbles or fizzing.
14.
Baking soda was the common ingredient in our chemical reactions. What happens when I add water to just baking soda?
Correct Answer
A. Baking soda dissolves
Explanation
When water is added to baking soda, it dissolves. Baking soda is a soluble compound, which means it can be dissolved in water. When it dissolves, it forms a solution in which the baking soda molecules are evenly dispersed throughout the water molecules. This process is known as dissolution. No gas, chalk, or fire is produced when water is added to baking soda.
15.
What gas do they use in fire extinguishers to put out fires?
Correct Answer
A. Carbon dioxide
Explanation
Carbon dioxide is used in fire extinguishers to put out fires because it is a non-flammable gas that displaces oxygen. When carbon dioxide is released from a fire extinguisher, it forms a blanket over the fire, cutting off the supply of oxygen and suffocating the flames. This effectively extinguishes the fire by removing one of the three elements necessary for combustion: oxygen. Oxygen, hydrogen, and nitrogen are not commonly used in fire extinguishers because they are either flammable or do not have the same suffocating effect as carbon dioxide.
16.
Which is less soluble: salt or citric acid
Correct Answer
A. Salt
Explanation
Salt is less soluble than citric acid. Solubility refers to the ability of a substance to dissolve in a solvent. In this case, since salt is less soluble, it means that it has a lower ability to dissolve in a solvent compared to citric acid.
17.
How can solutions be separated?
Correct Answer
A. Evaporation
Explanation
Solutions can be separated through the process of evaporation. This involves heating the solution to a high temperature, causing the solvent (usually water) to evaporate and leave behind the solute. The evaporated solvent can then be collected and condensed to obtain a pure form of the solvent. This method is commonly used to separate mixtures of liquids or dissolve solids in a liquid.
18.
Is it more accurate to measure in centimeters or meters?
Correct Answer
A. Centimeters
Explanation
It is more accurate to measure in centimeters because centimeters provide a smaller unit of measurement compared to meters. This allows for more precise measurements, especially when dealing with smaller objects or distances. Meters, on the other hand, are better suited for larger measurements and longer distances. Therefore, for accuracy and precision, centimeters are the preferred unit of measurement.
19.
How did we know when our solutions were saturated?
Correct Answer
A. There was solute at the bottom
Explanation
When there is solute at the bottom, it indicates that the solution is saturated. Solute particles that are unable to dissolve any further settle down at the bottom, indicating that the solution cannot hold any more solute. This is a clear visual indication that the solution has reached its saturation point.
20.
What could I do to test a mixture that I believe could be a solution?
Correct Answer
A. Filter it and observe that it can't be separated
Explanation
To test a mixture that is believed to be a solution, filtering it and observing that it cannot be separated is a suitable approach. This suggests that the components of the mixture are completely dissolved and evenly distributed, indicating a solution rather than a suspension or colloid. By filtering the mixture and finding that it cannot be separated into distinct phases, it confirms the homogeneous nature of the solution.
21.
If I used water that had been in the refrigerator would it dissolve more or less solute than warm water from the sink?
Correct Answer
A. Less
Explanation
Using water that has been in the refrigerator would dissolve less solute than warm water from the sink. This is because cold water has a lower kinetic energy compared to warm water. The lower kinetic energy of cold water molecules slows down the dissolution process, making it less effective in dissolving solutes. On the other hand, warm water molecules have higher kinetic energy, which increases the rate of dissolution and allows it to dissolve more solute.
22.
Will concentration go up forever if I just keep adding solute?
Correct Answer
A. No
Explanation
Concentration will not go up forever if solute is continuously added because there is a limit to the amount of solute that can dissolve in a given amount of solvent. Once the solvent becomes saturated with solute, adding more solute will not increase the concentration. At this point, any additional solute added will remain undissolved. Therefore, concentration cannot continue to increase indefinitely.
23.
We combined calcium chloride and baking soda. This produced chalk and salt water. Name a reactant in the reaction
Correct Answer
A. Calcium chloride
Explanation
The reactant in the reaction is calcium chloride.
24.
Which one is the correct diagram for the items included?
Correct Answer
A.
25.
Which solution has the lowest concentration?
Correct Answer
A. A & B
Explanation
The solution with the lowest concentration is A & B. This means that both solution A and solution B have a lower concentration compared to the other options (C and all of the above).