HESI A2
HESI A2 Chemistry Questions
Question 1 of 5
What is the name of the compound CH₃-CH₂-CH₂-CH₃?
Correct Answer: B
Rationale: The correct answer is B: Butane. In this compound, CH₃-CH₂-CH₂-CH₃, there are four carbon atoms connected in a straight chain, making it a butane. The prefix "but-" indicates that there are four carbon atoms, and the suffix "-ane" indicates that the compound contains only single bonds between the carbon atoms. Therefore, the correct name is Butane. Choice A: Cyclobutane is incorrect because it would be a cyclic compound with four carbon atoms forming a ring. Choice C: Butene is incorrect because it would have a double bond between two carbon atoms, making it an alkene. Choice D: Butyne is incorrect because it would have a triple bond between two carbon atoms, making it an alkyne.
Question 2 of 5
Here are the solubilities of four substances at 0�C, in grams of solute per 100 mL of water. If the temperature increases to 20�C, what would you expect to happen to the solubility figures?
Correct Answer: C
Rationale: Failed to generate a rationale after 5 retries.
Question 3 of 5
What is the name of the compound CH₃-CH₂-CH₂-CH₃?
Correct Answer: B
Rationale: The correct answer is B: Butane. In this compound, CH₃-CH₂-CH₂-CH₃, there are four carbon atoms connected in a straight chain, making it a butane. The prefix "but-" indicates that there are four carbon atoms, and the suffix "-ane" indicates that the compound contains only single bonds between the carbon atoms. Therefore, the correct name is Butane. Choice A: Cyclobutane is incorrect because it would be a cyclic compound with four carbon atoms forming a ring. Choice C: Butene is incorrect because it would have a double bond between two carbon atoms, making it an alkene. Choice D: Butyne is incorrect because it would have a triple bond between two carbon atoms, making it an alkyne.
Question 4 of 5
The three important allotropic forms of phosphorus are red, white, and ___________.
Correct Answer: C
Rationale: The correct answer is C: black. Red and white phosphorus are well-known allotropes. Black phosphorus is another important allotrope with a layered structure. It is stable at room temperature and has unique electronic properties. Green, gray, and silver are not commonly recognized allotropic forms of phosphorus, making them incorrect choices.
Question 5 of 5
If fifty-six kilograms of a radioactive substance has a half-life of 12 days, how many days will it take the substance to decay naturally to only 7 kilograms?
Correct Answer: C
Rationale: To determine the time for the substance to decay to 7 kg, we need to calculate the number of half-lives required. Each half-life reduces the substance by half. Given: Initial mass = 56 kg, Final mass = 7 kg, Half-life = 12 days. Number of half-lives = log(final mass / initial mass) / log(0.5) = log(7/56) / log(0.5) = 3.807 / -0.301 = -12.66. As the number of half-lives must be a whole number, we round up to 13 half-lives. Total time = 13 * 12 days = 156 days. Therefore, the correct answer is C (36 days). The other choices are incorrect because they do not accurately represent the calculation based on the half-life of the substance.
Similar Questions
Join Our Community Today!
Join Over 10,000+ nursing students using Nurselytic. Access Comprehensive study Guides curriculum for HESI A2-HESI A2 and 3000+ practice questions to help you pass your HESI A2-HESI A2 exam.
Subscribe for Unlimited Access