HESI A2
HESI A2 Version 1 Chemistry Questions
Extract:
Question 1 of 5
What is the density of iron if 28.5g of iron is added to a graduated cylinder containing 45.5mL of water, causing the water level to rise to the 49.1mL mark?
Correct Answer: B
Rationale: To calculate density, divide mass by volume. First, determine the volume of iron added by subtracting the initial volume of water from the final volume with iron. The volume of iron is calculated as 49.1mL - 45.5mL = 3.6mL. Density of iron is then determined as the mass of iron divided by the volume of iron, which equals 28.5g / 3.6mL = 7.92 g/mL. Therefore, the correct answer is B, 7.92 g/mL.
Question 2 of 5
What is the correct name for aqueous HI?
Correct Answer: A
Rationale: The correct name for aqueous HI is hydroiodic acid. In the naming of binary acids, the prefix 'hydro-' is combined with the root of the nonmetal element and the suffix '-ic acid'. Therefore, the correct systematic name for HI in aqueous solution is hydroiodic acid.
Question 3 of 5
What is the name for the horizontal rows of the periodic table?
Correct Answer: B
Rationale: In the periodic table, the horizontal rows are called 'periods.' These periods represent the number of electron shells an element has. Each period starts a new energy level, indicating the elements' properties and atomic structure. 'Groups' refer to the vertical columns of the periodic table, each containing elements with similar chemical properties. 'Families' can also be used interchangeably with groups. 'Sets' is a vague term and not specifically related to the layout of the periodic table. Understanding the distinction between 'periods' and 'groups' is crucial in comprehending the organization and properties of elements in the periodic table.
Question 4 of 5
What is a benefit of water's ability to make hydrogen bonds?
Correct Answer: D
Rationale: The correct answer is D - High specific heat. Water's ability to make hydrogen bonds leads to a high specific heat capacity, which allows it to absorb and release large amounts of heat with minimal temperature change. This property is crucial for maintaining stable temperatures in living organisms and aquatic environments. High specific heat helps regulate body temperature in organisms and prevents sudden temperature fluctuations in water bodies, providing an essential benefit for various biological processes.
Question 5 of 5
What are bases or alkaline solutions known as?
Correct Answer: A
Rationale: Bases or alkaline solutions are substances that can accept protons (H+ ions), making them hydrogen acceptors. When a base reacts with an acid, it accepts a proton to form water, hence neutralizing the acid. This property distinguishes bases from acids, which donate protons (H+ ions). Therefore, the correct answer is that bases or alkaline solutions are known as hydrogen acceptors.