Biology QUIZ
If the pH of a solution is 6, what is the concentration of protons? 0.6 M 106 M 6 M 10-6 M 60 M
10^-6 M
Ice floats in liquid water because ice has a lower ______ than liquid water.
Density
Compared with liquid water, ice has fewer hydrogen bonds between individual water molecules a more orderly arrangement of water molecules a less orderly arrangement of water molecules greater hydrogen bonds between individual water molecules
a more orderly arrangement of water molecules greater hydrogen bonds between individual water molecules
When water vaporizes at an ordinary temperature, the process is known as
evaporation
to freeze water, energy is
released
What happens to the pH of a solution when H+ ions are added to it? The pH increases The pH remains the same The pH becomes more alkaline The pH decreases
the pH decreases
If a solution has a pH of 8, what is the concentration of protons in the solution? 8 M 80 M 10^-8 M 0.8 M
10^-8
In humans, water comprises approximately ______ of body weight. 80-90% 60-70% 40-50% 20-30%
60-70%
Which of the following changes in the physical state of water require the input of energy?
Changing from solid to liquid Changing from liquid to gas
Which state of water is the most dense? Solid Gas Liquid
Liquid
Which component of humans has the greatest percent of water? Brain Bones Lungs Blood
Lungs
What is the molarity of a solution? The number of grams of solute in 1 L The mass of 1 L of solution The number of moles of solute in 1 L
The number of moles of solute in 1 L
If you add H+ ions to a solution, it becomes more:
acidic
A solution in which water is the solvent is called a(n)________ solution.
aqueous
Hydrolysis reactions: create molecules via the loss of a smaller molecule create molecules via the loss of water break apart molecules via water
break apart molecules via water
What type of compound minimizes pH fluctuations in the fluids of living organisms? water base buffer acid
buffer
Hydrochloric acid is considered an acid because it releases __________________ ions into solution.
hydrogen
The ______ of a solution is the negative base 10 logarithm of the H+ concentration of the solution. heat capacity equilibrium constant pH heat of vaporization
pH
The concentration of a liquid is defined as the amount of ______ dissolved in a unit volume of solution. solute moles solvent
solute
Substances dissolved in liquid are known as micelles. solutes. solvents. microbes.
solutes.
An aqueous solution is one in which the solvent is hydrophobic. an oil. water.
water
Which of the following contributes to water's stability in a liquid state? A low surface tension A high heat of fusion A low specific heat A high heat of vaporization
A high heat of fusion A high heat of vaporization
A substance that absorbs hydrogen ions in solution is called a(n) salt. isotope. acid. base.
base
A solution is composed of ______ dissolved in a(n) ______. products; reactants solutes; solvent reactants; products solvent; solutes
solutes; solvent
Solutes dissolved in a solvent form a(n): suspension catalyst chemical reaction solution
solution
An aqueous solution is one in which the solvent is hydrophobic. water. an oil.
water.
The molecular mass of a molecule is equal to: the sum of the atomic masses of all atoms in the molecule the number of atoms in the molecule the average of the atomic masses of all atoms in the molecule
the sum of the atomic masses of all atoms in the molecule
Water does not break up when an insect lands on its surface, a property known as surface tension. What property of water best explains surface tension? High specific heat Molarity Cohesion High heat of vaporization Adhesion
Cohesion
In a(n)______________reaction, water is used to break apart another molecule.
hydrolysis
When water freezes: the rate of hydrogen bond breakage slows water loses its hydrophilic status and becomes more hydrophobic water molecules are packed into a less dense formation the H2O molecules in ice are in a much more orderly arrangement than in the liquid state
the rate of hydrogen bond breakage slows water molecules are packed into a less dense formation the H2O molecules in ice are in a much more orderly arrangement than in the liquid state
Which of the following solutions contains the highest concentration of protons? A solution with pH 10.0 A solution with pH 5.0 A solution with pH 7.0 A solution with pH 2.0
A solution with pH 2.0
Put the physical states of water in order based on the intermolecular distances between water molecules. The TOP position should be the state in which the molecules are the farthest apart. Liquid Gas Solid
Gas, Solid, and Liquid
When water is heated, the rate at which_________bonds break increases, and water molecules are converted to the____ state.
H; gas
Why does ice float in liquid water? Liquid water is less electronegative in ice. Water molecules form few hydrogen bonds with each other in ice. Ice solidifies around a hollow core. Ice is less dense than liquid water.
Ice is less dense than liquid water.
When water ionizes, it produces what ions? Select all that apply. OH+ O2 H- OH- H+
OH- H+
A solution at pH 5 is said to be ______ because it contains more ______. acidic; H+ ions than OH- ions acidic; OH- ions than H+ ions basic; OH- ions than H+ ions basic; H+ ions than OH- ions
acidic; H+ ions than OH- ions
A substance that releases hydrogen ions into solution is called a(n)
acids
The phenomenon of water molecules attracting one another is known as_______________, whereas the process of water molecules being attracted to non-neutral surfaces is known as_________________.
cohesion; adhesion
The amount of solute (in grams) dissolved in a given volume of solution is the solution's: concentration solvent molecular mass equilibrium
concentration
A base will release___________ ions when dissolved in water.
hydroxide
The number of moles of a solute dissolved in one liter of solution is the solution's molarity. mass. polarity. solvent.
molarity
The sum of the atomic masses of all atoms in a molecule is equal to the molecule's___________________ mass.
molecular
Water has a high heat of fusion. This means that: covalent bonds must replace hydrogen bonds to form ice much energy must be added to cause gaseous water to change to the liquid state much energy must be withdrawn to cause water to change from a liquid state to solid
much energy must be withdrawn to cause water to change from a liquid state to solid
pH is defined the ______________ ________________ to the base of 10 of the __________________ ion concentration.
negative logarithm; H+
Pure water can ionize into positively charged hydroxide (OH+) ions and negatively charged protons (H-). negatively charged dihydroxide (H2-) ions and positively charged oxygen ions (O+). positively charged dihydroxide (H2+) ions and negatively charged oxygen ions (O-). positively charged protons (H+) and negatively charged hydroxide (OH-) ions.
positively charged protons (H+) and negatively charged hydroxide (OH-) ions.
A liquid that can dissolve substances is known as a(n)
solvent
Even though it requires energy to change water from a liquid to a gas, some water molecules break their hydrogen bonds at an ordinary temperature (evaporate) by: vibrating at a higher energy increasing adhesion using their colligative properties increasing heat capacity
vibrating at a higher energy
Rank each state of water in order of increasing density, starting with the least dense state at the top of the list. ice water vapor liquid water
water vapor ice liquid