HESI A2 CHEMISTRY REVIEW NURSEHUB EXAM

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HESI A2 CHEMISTRY REVIEW (NURSEHUB) EXAM

QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -33 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: Which of the following does pH measure?

The concentration of hydrogen ions The strength of an acid Acid concentration The concentration of hydroxide ions

Answer:

The concentration of hydrogen ions pH is defined mathematically as -log[H+]. As you can see, it is a measure of the concentration of hydrogen ions. Although we use pH to determine the acidity of a solution, it does not give any indication as to the strength of an acid (that is what pka does).

Question 2: Which of the following is not an intermolecular force?

Dipole-dipole interaction Dispersion force Hydrogen bond Metallic bond

Answer:

Metallic bond Metallic bonds hold metal lattices together and are an intramolecular force. Other examples of intramolecular forces are covalent bonds and ionic bonds. The other options are intermolecular forces that determine how other molecules interact with one another.

Question 3: An atom with a net positive or negative charge due to an unequal number of protons and electrons

Answer:

Ion

Question 4: Which of the following pH values is acidic?

5 7 11 13

Answer:

5 The pH scale is centered around a pH of 7, which is considered to be neutral. Values below 7 are considered to be acidic, while values greater than 7 are basic.

Question 5: Kelvin

The Kelvin temperature scale is an absolute temperature scale, meaning its lowest value is zero.0°K is known as "absolute zero," where all molecular motion stops.Joule isn't a measurement of temperature at all (it is a measurement of energy), while Fahrenheit and Celsius both allow for negative temperature values.

Answer:

What are the three main components of a number that is expressed in scientific notation?Significant digit, mathematical sign, and exponential Exponential, logarithm, and mathematical sign Mathematical sign, significand, and exponential Mathematical sign, root, and exponential

Question 6: 10

Answer:

Which of the following occurs at 100°C?Ice melts Pure water boils Pure water sublimes Pure water freezes

Question 7: 100 degrees Celsius

The Kelvin scale is an extension of the Celsius scale, so the same magnitude of decrease on the Kelvin scale will result in the same decrease on the Celsius scale. Another way of look at this is that Kelvin is always 273.15 more than Celsius. So, if there is a 100-degree decrease in Celsius, there will also be a decrease of 100 Kelvins.

Answer:

On which of the following temperature scales can a negative number not exist?Joule Fahrenheit Kelvin Celsius Question 8: How many total amino acids are needed for the human body to produce all the proteins it needs?20 10 11 9

Answer:

20 Amino acids, which contain an amine and a carboxylic acid, are needed by the body to produce proteins. There are 20 amino acids that the body needs for protein synthesis, and they are grouped into

two categories: essential and non-essential.

Question 9: Which of the following is the correct term for chemicals on the left side of the reaction arrow?

Answer:

Which of the following solvents are lipids insoluble in?Water Dichloromethane Ethanol Chloroform

Question 10: Which of the following describes a catalyst?

A solid that precipitates out of a reaction A gas that evolves from the reaction A substance that slows down a reaction.A substance that increases the rate of a chemical reaction

Answer:

A substance that increases the rate of a chemical reaction

Question 11: Water

A lipid is defined as a molecule that is insoluble in water, but that is soluble in organic solvents such as ethanol, chloroform, and dichloromethane. Because of this, lipids are considered hydrophobic.

Answer:

Why does increasing the surface area of reactants or catalysts increase the rate of a reaction?It reduces the amount of precipitate that is formed during the reaction.It introduces charges on the surface of the particles, which makes them more reactive.It increases the likelihood of molecules encountering one another.The activation energy of the reaction is lowered.

Question 12: What is the oxidation number of oxygen?

2- 1- 1+

Answer:

2- Oxygen is part of the Group 16 of the periodic table and carries a 2- charge. This is because it prefers to gain two electrons to form a full octet to adopt the electron configuration of the closest noble gas (Neon).

Question 13: Which of the following is not likely to have a dipole?

Nonpolar compound Salt Polar compound Ionic compound

Answer:

Nonpolar compound A dipole occurs when there is an unequal sharing of electrons between two atoms in a molecule. In the dipole, there will be both a partially - positive and a partially-negative side. The more electronegative atom will be on the partially-negative side since it will be able to attract more electrons to itself.

Question 14: Meter

Answer:

Which of the following is the SI unit used to measure the amount of a substance?Gram Mole Kilogram Meter Question 15: Which of the following phase transition describes the change from ice into steam?Melting Sublimation Evaporation Freezing

Answer:

Sublimation