Question 1

Which of the following statements best explains why water is considered a 'universal solvent' in biological systems?

Accepted Answer

Water molecules are polar, allowing them to surround and separate many ionic and polar substances.

Question 2

A neutral atom of phosphorus has an atomic number of 15 and an atomic mass of 31. How many neutrons does it have?

Accepted Answer

16

Question 3

Which of the following best describes the difference between a cation and an anion?

Accepted Answer

A cation is positively charged due to loss of electrons, while an anion is negatively charged due to gain of electrons.

Question 4

Which property of water is most directly responsible for the cooling effect of sweating in humans?

Accepted Answer

Evaporative cooling

Question 5

A sodium atom (Na) has 11 protons and 11 electrons. After losing one electron to form Na+, what is the resulting charge and number of electrons?

Accepted Answer

Charge: +1, Electrons: 10

Question 6

Which of the following best explains why oxygen and hydrogen atoms in a water molecule have partial charges?

Accepted Answer

Oxygen is more electronegative than hydrogen, so electrons are pulled closer to oxygen.

Question 7

Which of the following is a correct electron configuration for a neutral atom with 16 electrons?

Accepted Answer

2 in the first shell, 8 in the second, 6 in the third

Question 8

Which of the following best describes an isotope?

Accepted Answer

Atoms of the same element with different numbers of neutrons

Question 9

A chemical equation is written as: 2H2 + O2 → 2H2O. What does the coefficient '2' in front of H2O indicate?

Accepted Answer

Two molecules of water are produced for every two molecules of hydrogen and one molecule of oxygen.

Question 10

Which of the following best explains why carbon, hydrogen, nitrogen, and oxygen make up the majority of human body mass?

Accepted Answer

They are essential for forming the major biological molecules in living organisms.

Question 11

Which of the following is a real-life example of adhesion?

Accepted Answer

Water climbing up a plant stem

Question 12

A solution is made by dissolving table salt in water. In this solution, which is the solute and which is the solvent?

Accepted Answer

Salt is the solute; water is the solvent.

Question 13

Which of the following best describes a polar covalent bond?

Accepted Answer

Electrons are shared unequally, resulting in partial charges on the atoms.

Question 14

If a neutral atom of magnesium (atomic number 12, atomic mass 24) loses two electrons, what is its resulting charge and number of electrons?

Accepted Answer

Charge: +2, Electrons: 10

Question 15

Which of the following best explains why hydrogen bonds are important in biological molecules?

Accepted Answer

They stabilize the structures of large molecules like proteins and DNA by providing weak, reversible attractions.

Question 16

A student is analyzing a solution with a pH of 3. Which of the following statements is correct about this solution?

Accepted Answer

It is acidic and has a higher concentration of H+ ions than OH- ions.

Question 17

Which of the following best describes the relationship between atomic number and the identity of an element?

Accepted Answer

The atomic number is the number of protons and uniquely identifies the element.

Question 18

Which of the following best explains why the third energy level of an atom can hold up to 18 electrons?

Accepted Answer

It is larger and has more sublevels than the first and second energy levels.

Question 19

In the photosynthesis equation: 6CO2 + 6H2O → C6H12O6 + 6O2, how many total oxygen atoms are present among the reactants?

Accepted Answer

12

Basic Chemistry Study Notes for General Chemistry

Study Guide - Practice Questions