Sasha did an experiment to study the solubility of two substances. She poured 100 mL of water at 20 °C into each of two beakers labeled A and B. She put 50 g of Substance A in the beaker labeled A and 50 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.

Question

Sasha did an experiment to study the solubility of two substances. She poured 100 mL of water at 20 °C into each of two beakers labeled A and B. She put 50 g of Substance A in the beaker labeled A and 50 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 12 11 9 8
B 45 40 34 31

Part 1: Which substance has a higher solubility?

Part 2: Explain your answer for Part 1.

Answer 1

Part 1: Substance A has a higher solubility than Substance B.

Part 2: Substance A has a higher solubility because at each temperature, the amount of substance A left undissolved is lower than the amount of substance B left undissolved. This suggests that substance A is more soluble in water than substance B.

Answer 2

Part 1: Substance A has a higher solubility.

Part 2: The solubility of a substance refers to how well it dissolves in a given solvent. In this experiment, both substances, A and B, were dissolved in water at different temperatures. By comparing the mass of undissolved substance at each temperature, we can determine the solubility.

At all temperatures, Substance A had a smaller mass of undissolved substance compared to Substance B. For example, at 20 °C, Substance A had a mass of 12 grams left undissolved, whereas Substance B had a mass of 45 grams left undissolved.

Furthermore, as the temperature increased from 20 °C to 80 °C, the mass of undissolved Substance A decreased (12 g to 8 g), indicating that Substance A became more soluble with increasing temperature. Similarly, the mass of undissolved Substance B also decreased, but not as much as Substance A, indicating a lower solubility.

Based on these observations, we can conclude that Substance A has a higher solubility compared to Substance B.

Answer 3

Part 1: To determine which substance has a higher solubility, we need to compare the amount of substance left undissolved in each beaker at different temperatures. In this case, we have Substance A and Substance B.

Part 2: To compare the solubility, we look at the mass of undissolved substance at different temperatures for both Substance A and Substance B.

For Substance A:
- At 20 °C, there is 12g of undissolved substance.
- At 40 °C, there is 11g of undissolved substance.
- At 60 °C, there is 9g of undissolved substance.
- At 80 °C, there is 8g of undissolved substance.

For Substance B:
- At 20 °C, there is 45g of undissolved substance.
- At 40 °C, there is 40g of undissolved substance.
- At 60 °C, there is 34g of undissolved substance.
- At 80 °C, there is 31g of undissolved substance.

From these observations, we can see that Substance A has a lower amount of undissolved substance compared to Substance B at each temperature. This indicates that Substance A has a higher solubility than Substance B.

Therefore, our answer for Part 1 is that Substance A has a higher solubility compared to Substance B.