HESI Chemistry Practice Test 2
Reactions that absorb heat are called what?
Explanation:
Endothermic reactions absorb heat, while exothermic reactions give off heat.
What is the most abundant element in Earth’s crust?
Explanation:
Oxygen makes up about 47% of the Earth’s mass, followed by Silicon at 28%, Aluminum at 8%, Iron at 5%, Calcium at 4%, and Sodium and Potassium, each at 3%.
Viscosity increases in what circumstance?
Explanation:
Viscosity, or the resistance of a fluid against force, increases with a temperature decrease, that is, fluid becomes more viscous (flows slower) in colder temperatures.
Lisa prepares soup by combining spices in a saucepan of boiling water and stirring until the spices are completely dissolved. She then adds a variety of diced veggies. What is the solute in her mixture?
Explanation:
A solute is a material that dissolves when it comes into contact with another substance. The spices are the solute in this situation.
Which one of the following elements is liquid at room temperature?
Explanation:
Mercury is the only element that is liquid at room temperature.
Which of the following elements does not appear on the periodic table?
Explanation:
Because it is a combination of two elements, magnesium oxide does not appear on the periodic table.
The change in state from a gas to liquid is called what?
Explanation:
Condensation is the reverse of vaporization and can be observed when gas cools and becomes a liquid, such as when dew appears in the morning after the temperature drops at night.
A solution that contains the maximum amount of dissolved solute is said to be what?
Explanation:
A saturated solution is one that has the maximum amount of solvent dissolved into it.
Which of the following is true of gas particles?
Explanation:
Gas particles exert little to no force on each other, so they “bounce” off each other when they collide. The other options are all false regarding gas particles.
What is the most abundant element in the universe?
Explanation:
Hydrogen is the most abundant element in the universe, followed by Helium and then Oxygen.
Which of the following would produce Hydrogen ions in an aqueous solution and would turn a litmus test from blue to red?
Explanation:
Blue litmus paper turns red in the presence of an acid. Ammonia, lye, and detergent are basic, so they would not give off Hydrogen ions in an aqueous solution and when added to blue litmus paper the paper would remain blue.
Using the Lewis-dot structure model, how many dots would carbon have?
Explanation:
The number of dots in a Lewis-dot structure model corresponds to the number of valance electrons for that atom. Because carbon has four valance electrons, it’s Lewis-dot structure model would have 4 dots.
Which of the following is not a property of water?
Explanation:
This is the only answer choice that is not true, as the question asks.
All of the following factors influence the pace of a chemical reaction except?
Explanation:
The pace of a chemical reaction is not affected by the quantity of mass lost since the law of conservation of mass (or matter) stipulates that there is no mass loss in a chemical reaction.
Dihydrogen monoxide is better known as what?
Explanation:
Dihydrogen monoxide, or H2O, is more commonly known as water.
Which of the following statements about most metals is false?
Explanation:
Metals are generally solids at ambient temperature, whereas nonmetals are usually gaseous.