EOM: Aqueous Solutions

Grace and Michael are making a sweet drink. Can you help them figure out which is the solute and which is the solvent?

• Water is the solvent, and sugar is the solute.

• Sugar is the solvent, and water is the solute.

• Water and sugar are both solvents; the finished solution is the solute.

• Water and sugar are both solutes; the finished solution is the solvent.

Answer explanation

In a solution, the solvent is the substance that dissolves the solute. Here, water dissolves sugar, making water the solvent and sugar the solute.

Aria and David are conducting a fun experiment in their chemistry class. They want to find out which of the following illustrations would NOT help them speed up the process of dissolving solid solutes in water. Can you help them figure it out?

• A. 4 only

• B. 1 and 2 only

• C. 1, 2, and 3 only

• D. 1, 2, 3, and 4

Answer explanation

Illustration 4 does not contribute to speeding up the dissolving process, as it likely represents a method that does not enhance solute interaction with water. Therefore, the correct answer is A. 4 only.

Liam and Avery are conducting a fun science experiment in their kitchen. They dissolve 12 g of NaCl (salt) into a beaker containing 50 mL of water at room temperature. How could they dilute their salty concoction?

• The solution cannot be diluted.

• To dilute the solution, add more salt and water in the original proportion.

• To dilute the solution, add more salt.

• To dilute the solution, add more water.

Answer explanation

To dilute the salty solution, Liam and Avery should add more water. This increases the volume of the solution and decreases the concentration of salt, making it less salty.

In a fun science experiment, Noah, Aiden, and Abigail each add 15 g of four different magical solutes to their beakers, each containing 30 mL of enchanted water. After 2 minutes of stirring with their magic wands, they remove the remaining solute from each beaker and weigh it. Which of the following solutions has the highest concentration of magic?

• Substance A

• Substance B

• Substance C

• Substance D

Answer explanation

Substance B has the highest concentration of magic because it retained the least amount of solute after stirring, indicating more solute dissolved in the enchanted water compared to the other substances.

Isla, Hannah, and Liam are on a mission to discover what makes salt dissolve faster in water! They each take turns adding salt to four different beakers, all containing the same amount of water. Using a magical magnetic stirrer, they set different stirring speeds to see how quickly the salt disappears. Check out their experiment setup below and help them figure out which factor they're testing: Amount of Water (mL) | Amount of Salt (mg) | Stirring Speed (rpm) | Water Temperature (°C) Beaker A: 500 | 600 | 150 | 20 Beaker B: 500 | 600 | 300 | 20 Beaker C: 500 | 600 | 450 | 20 Beaker D: 500 | 600 | 600 | 20

• Temperature

• Agitation

• Surface area

• Concentration

Answer explanation

The experiment tests how stirring speed (agitation) affects salt dissolution. All beakers have the same water amount, salt amount, and temperature, isolating agitation as the variable influencing dissolution rate.

Michael and Aria are conducting a science experiment to see how fast different substances dissolve in water. Which of the following factors should they consider to speed up the dissolution process?

• A. Surface area

• B. Amount of solvent

• C. Agitation

• D. Temperature

• E. Color of solvent

Answer explanation

To speed up dissolution, consider surface area (smaller pieces dissolve faster), agitation (stirring increases interaction), and temperature (higher temperatures increase solubility). Color of solvent is irrelevant.

Rohan, Elijah, and Luna are having a friendly competition to see which solutes dissolve the fastest in a solvent. Check out the image of different solutes they have. Can you help them by selecting the three solutes that would dissolve the fastest?

• Potassium chloride powder

• Ground salt

• Sugar cubes

• Salt block

• Ground sugar

Answer explanation

Potassium chloride powder, ground salt, and ground sugar dissolve fastest due to their smaller particle sizes, which increase surface area and enhance solubility in the solvent compared to larger forms like sugar cubes and salt blocks.

Scarlett and Rohan are conducting a fun experiment with a magical graph! Which statement best interprets their graph?

• As temperature increases, the solubility of solids increases.

• As temperature decreases, the solubility of solids increases.

• As temperature increases, the solubility of solids decreases.

• Temperature and the solubility of solids are not related.

Answer explanation

The correct interpretation is that as temperature increases, the solubility of solids increases. This is a common principle in chemistry, where higher temperatures typically allow more solid solute to dissolve in a solvent.

Imagine you're in a magical chemistry class with Scarlett, Nora, and Emma. Which statement best explains the answer to Part A?

• As the temperature rises, it's like the solvent is doing a happy dance, gaining kinetic energy. This energetic dance helps more solute particles break apart and join the party.

• As the temperature drops, it's like the solvent is doing a happy dance, gaining kinetic energy. This energetic dance helps more solute particles break apart and join the party.

• As the temperature rises, it's like the solvent is taking a nap, losing kinetic energy. This sleepy state helps more solute particles break apart and join the party.

• As the temperature drops, it's like the solvent is doing a happy dance, gaining kinetic energy. This energetic dance helps fewer solute particles break apart and join the party.

Answer explanation

The correct choice explains that as temperature rises, the solvent gains kinetic energy, allowing more solute particles to break apart and dissolve. This aligns with the principles of solubility and temperature effects.

Elijah and Maya are conducting a fun experiment in their science class. They want to know at what temperature 30 g of KCl will dissolve in 100 g of water. Can you help them find out?

• 20°C

• 30°C

• 40°C

• 50°C

Answer explanation

KCl has a solubility that increases with temperature. At 40°C, 30 g of KCl can dissolve in 100 g of water, making this the correct choice. Lower temperatures would not allow this amount to dissolve.