ATI TEAS VII Online Practice B- Chemistry Flashcards
A student observes that when the mercury rises and falls in a thermometer, the particles do not stick to the sides of the glass tube. However, when honey is poured from one glass to another, the particles stick to the container.
which of the following explains the observations?
A. Mercury is more cohesive and less adhesive than honey.
B. Mercury is less cohesive and more adhesive than honey
C. Mercury is less cohesive and less adhesive than honey
D. Mercury is more cohesive and more adhesive than honey.
A. Mercury is more cohesive and less adhesive than honey
Explanation:
Mercury atoms are more attracted to each other by cohesion than they are to glass by adhesion, while honey has high adhesion and sticks immediately to the glass surface. So, mercury rises and falls without any residue on the thermometer while honey sticks to the container
If an intensive property is independent of the amount of the material being measured, which of the following is an example of an intensive property?
A. Mass
B. Density
C. Volume
D. Length
B. Density
Explanation:
Density is a ratio of material present in a given volume. Water will have the same density whether in a bucket or in a cup. It is independent of the amount of material. Therefore, it is an intensive property.
Which of the following chemical bonds is found within a molecule of ammonia, NH3, given that N is a highly electronegative element and has a valence of 5?
A. Nonpolar covalent bonds
B. Polar covalent bonds
C. Ionic bonds
D. Hydrogen bonds
B. Polar covalent bonds
Explanation:
Nitrogen is more electronegative than hydrogen, leading to an unequal sharing of electrons, which is the definition of polar covalent bonds.
Which of the following describes the concentration of hydrogen ions in water with a pH of 7?
A. 10 power 7 M
B. 7 M
C. 0.7 M
D. 10 power -7 M
10 Power -7 M
The formula for pH is -log[H+].
Therefore, the concentration of hydrogen ions in water with a pH of 7 is 0.0000001 M (10 power -7)
A chlorine atom has 17 electrons and 17 protons. It forms an ionic bond with sodium and gains a negative charge. Which of the following is true for the chloride ion?
A. It is an anion with 18 electrons and 17 protons.
B. It is an anion with 18 electrons and 18 protons.
C. It is a cation with 17 electrons and 18 protons.
D. It is a cation with 18 electrons and 18 protons.
A. It is an anion with 18 electrons and 17 protons.
Explanation:
When a chlorine atom gains an electron, its negative charge increases by 1 and it is now called an anion.
An atom of lithium has 3 protons, 4 neutrons, and 3 electrons. What is this atom’s mass number?
A. 3
B. 6
C. 10
D. 7
D. 7
Explanation:
The mass number of an atom is the sum of the number of protons and neutrons in its nucleus.
A student placed 20 ml NaOH solution in a beaker and added 5 ml of HCl to it. Which of the following would happen when two substances are mixed?
A. Hydrogen gas is released
B. Carbon dioxide gas is produced
C. The pH of the resultant solution is reduced
D. The concentration of OH- ions is increased
The pH of the resultant solution is reduced.
(Acid donates H+ ions which combine with OH- ions to make water. The lower concentrations of OH- ions, lower the pH of the solution.)
Which of the following is true of enzyme-catalyzed reactions?
A. The enzyme is not consumed in the reaction.
B. The substrate is produced in the active site
C. The substrate remains unchanged during the reaction.
D. The enzyme raises the activation energy of the reaction.
A. The enzyme is not consumed in the reaction
Explanation:
The enzyme lowers the energy required to initiate the reaction without being consumed in the process.
Which of the following properties of water explains its characterization as the universal solvent?
A. Kinetic energy of liquid water molecules
B. High Specific heat
C. Polarity of water molecules
D. High surface tension
C. Polarity of water molecules
Explanation:
Polarity means water molecules can form shells around both positively and negatively charged particles. Therefore, water can solubilize ionic and covalent molecules with charge separation, making it a universal solvent.
