Let's analyze each experiment step-by-step:
### Experiment 1:
Situation:
- Two 250 mL samples of water are drawn from a deep well bored into a large underground salt (NaCl) deposit.
- Sample #1 is from the top of the well and initially at [tex]\(42^\circ C\)[/tex].
- Sample #2 is from a depth of 150 m and initially at [tex]\(8^\circ C\)[/tex].
- Both samples are allowed to come to room temperature ([tex]\(20^\circ C\)[/tex]) and 1 atm pressure.
- An NaCl precipitate is seen to form in Sample #1.
Solubility Information:
- The solubility of NaCl generally increases with temperature.
- Sample #1, initially being at a higher temperature ([tex]\(42^\circ C\)[/tex]), would dissolve more NaCl compared to Sample #2, which is at a lower initial temperature ([tex]\(8^\circ C\)[/tex]).
- As both samples cool (Sample #1) or warm up (Sample #2) to reach room temperature ([tex]\(20^\circ C\)[/tex]), the solubility of NaCl adjusts accordingly.
Observation:
- When Sample #1 cools from [tex]\(42^\circ C\)[/tex] to [tex]\(20^\circ C\)[/tex], the solubility of NaCl decreases, leading to precipitation of some of the dissolved salt.
- Since Sample #2 was initially at [tex]\(8^\circ C\)[/tex], and warming it to [tex]\(20^\circ C\)[/tex] increases its ability to hold dissolved salt, less NaCl precipitate will be formed compared to Sample #1.
Predicted Observation:
"A smaller mass of NaCl precipitate will form in Sample #2."
### Experiment 2:
Situation:
- A student sees tiny bubbles clinging to the inside of an unopened plastic bottle full of carbonated soft drink.
- The student opens the bottle and hears a loud hiss as the gas under pressure escapes.
Physics Explanation:
- When a bottle of carbonated drink is sealed, the pressure inside is higher than the atmospheric pressure and the CO[tex]\(_2\)[/tex] is dissolved in the liquid.
- Upon opening the bottle, the pressure inside the bottle drops quickly to match the atmospheric pressure.
- This sudden pressure drop causes the dissolved CO[tex]\(_2\)[/tex] to come out of the solution and form bubbles.
Observation:
- The initial sight of tiny bubbles clinging to the bottle is due to the higher pressure keeping CO[tex]\(_2\)[/tex] dissolved in the liquid.
- Upon opening, the decrease in pressure allows more CO[tex]\(_2\)[/tex] to escape, causing the bubbles to grow and more bubbles to appear.
Predicted Observation:
"The bubbles will grow, and more may appear."
Thus, based on the explanation provided:
1. Experiment 1: A smaller mass of NaCl precipitate will form in Sample #2.
2. Experiment 2: The bubbles will grow, and more may appear.
