June 2024 Chemistry Regents #36-40
Highlight to reveal answers and explanations
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Questions |
Answer | Links |
Explanations |
| 36. Which numerical setup can be used to calculate
the formula mass of C9H11NO2? 1. 9u + 11u + 1u +2u 2. 12u + 1u +14u +16u 3. 9(6u) +11(1u) +1(7u) + 2(8u) 4. 9(12u) + 11(1u) + 1(14u) + 2(16u) |
4 | Formula mass is the atomic masses added up they used u=atomic mass units 99% of the time we use grams/mol don't let the Regents get you on this one |
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| 37. Based on Table F, which compound is most soluble
in water? 1. calcium bromide 2 lead(II) sulfate 3 silver carbonate 4 tin(II) hydroxide |
4 | hydroxides are insoluble
(tin is not in group 1) |
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| 38. Based on Table G, which combination of solute and
solvent will form a saturated solution when thoroughly mixed at 20.oC? 1. 15 grams of KClO3 in 100. grams of H2O 2. 20. grams of KCl in 100. grams of H2O 3. 30. grams of NaCl in 100. grams of H2O 4. 35 grams of KI in 100. grams of H2O |
1 | This is a new version of the question. only choice A
is above the line.
You were told that is supersaturated and on the line is saturated. If you reread the question, it never says all of it dissolved, just mixed. there is more than enough in there to make it saturated |
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| 39. A solution has a mass of 2000 grams and contains
0.050 grams of dissolved solute. What is the concentration in parts
per million of this solution? 1. 5.0 ppm 2. 25 ppm 3. 50. ppm 4. 100. ppm |
2 | ppm equation is on the back page plug in the numbers 0.050/2000 x 1,000,000=25ppm |
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| 40. A person with a body temperature of 37oC
holds a cup of hot water in their hands. The temperature of the cup
is 44oC. The air temperature is 22oC. Which
phrase describes a heat transfer that occurs in this system? 1. from the air to the cup 2. from the hand to the cup 3. from the air to the hand 4. from the cup to the hand |
4 | heat transfers from hot to cold cup hand air ------>
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