Biology Chapter: Equilibrium and Water Properties
48 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What happens to the rate of the forward reaction when the concentration of the reactants decreases at equilibrium?

  • It becomes the same as the reverse reaction.
  • It remains the same.
  • It decreases. (correct)
  • It increases immediately.
  • Which principle explains the shift in equilibrium when a concentration change occurs?

  • The Ideal Gas Law
  • Raoult's Law
  • The Law of Conservation of Mass
  • Le Châtelier’s Principle (correct)
  • What occurs to oxygen transport in hyposia conditions?

  • Oxygen levels remain unchanged.
  • Oxygen is released from hemoglobin. (correct)
  • Oxygen levels double in the tissues.
  • Oxygen is entirely retained by hemoglobin.
  • What can occur to the body after adapting to high altitude for about 10 days?

    <p>Increased red blood cell production (C)</p> Signup and view all the answers

    What characterizes hypoxia?

    <p>Cyanosis in the skin (A)</p> Signup and view all the answers

    At high altitudes, how much less oxygen does a person obtain compared to sea level?

    <p>29% less (B)</p> Signup and view all the answers

    According to the oxygen-hemoglobin equilibrium, what happens when oxygen levels are high?

    <p>Oxygen binds to hemoglobin, forming oxyhemoglobin. (D)</p> Signup and view all the answers

    What immediate treatments are recommended for altitude sickness?

    <p>Hydration, rest, and descending to a lower altitude (C)</p> Signup and view all the answers

    What unique feature does water have regarding its density at different states?

    <p>Water is less dense in its solid state than in its liquid state. (D)</p> Signup and view all the answers

    What role do hydrogen ions and hydroxide ions play in biological systems?

    <p>They are critical determinants of the structure and function of biomolecules. (D)</p> Signup and view all the answers

    What property of water causes it to have a high boiling point and heat of vaporization?

    <p>Its high intermolecular forces due to hydrogen bonding. (A)</p> Signup and view all the answers

    How does the polarity of water affect its behavior as a solvent?

    <p>Water can dissolve ionic and polar substances effectively. (A)</p> Signup and view all the answers

    What is a key reason for water's high surface tension?

    <p>The strong intermolecular forces between water molecules. (A)</p> Signup and view all the answers

    What is the term for the phenomenon where a difference in hydrogen ion concentration across a membrane creates energy?

    <p>Membrane potential. (A)</p> Signup and view all the answers

    What is the significance of water's heat of vaporization in biological systems?

    <p>It contributes to cooling mechanisms in organisms. (A)</p> Signup and view all the answers

    What characteristic does water exhibit due to permanent dipoles in its molecules?

    <p>It exhibits strong cohesive properties. (D)</p> Signup and view all the answers

    Which statement accurately describes the effect of solutes on the structure of liquid water?

    <p>Solutes fix nearby water molecules in a more ordered array. (C)</p> Signup and view all the answers

    What is the primary characteristic of colligative properties?

    <p>They are determined only by the concentration of solute. (C)</p> Signup and view all the answers

    Which of the following is an example of a colligative property?

    <p>Freezing point depression. (C)</p> Signup and view all the answers

    How does osmotic pressure relate to the contents of a cell's cytosol?

    <p>Osmotic pressure increases with the number of free glucose molecules. (B)</p> Signup and view all the answers

    What effect does boiling point elevation have on a solution with dissolved substances?

    <p>It increases the temperature at which the solution boils. (B)</p> Signup and view all the answers

    What is the primary reason for freezing point depression when using rock salt?

    <p>Rock salt causes solutes to disrupt the liquid water structure. (A)</p> Signup and view all the answers

    How does vapor pressure relate to the transition of water from liquid to gas?

    <p>Vapor pressure is the pressure exerted when water is in equilibrium. (B)</p> Signup and view all the answers

    The process of creating micelles involves interaction with which type of molecules?

    <p>Amphiphilic molecules containing both polar and nonpolar groups. (A)</p> Signup and view all the answers

    What characterizes Brønsted-Lowry acids and bases?

    <p>They always exist as conjugate acid-base pairs. (A)</p> Signup and view all the answers

    Which type of arrow is used to represent the ionization of strong acids?

    <p>Single arrow (C)</p> Signup and view all the answers

    What is the pH of a 0.15 M solution of hydrochloric acid?

    <p>0.85 (D)</p> Signup and view all the answers

    Which statement is true regarding strong acids and bases?

    <p>Strong acids completely dissociate in water. (C)</p> Signup and view all the answers

    If a solution has a pH of 8.5, what is the molarity of hydrogen ions in the solution?

    <p>3.16 x 10^-8 M (C)</p> Signup and view all the answers

    What is the relationship between pH and pOH in aqueous solutions?

    <p>pH + pOH = 14 (D)</p> Signup and view all the answers

    What is the pH of a solution if the hydronium ion concentration is $1.7 x 10^{-3} M$?

    <p>2.77 (D)</p> Signup and view all the answers

    Which hydroxides are typically considered strong bases?

    <p>Hydroxides of Group I and Group II metals (C)</p> Signup and view all the answers

    What is the primary function of bicarbonate in the body's buffering system?

    <p>To maintain a stable pH by neutralizing excess acids. (C)</p> Signup and view all the answers

    What condition is characterized by a decrease in carbon dioxide levels leading to a higher blood pH?

    <p>Alkalosis (C)</p> Signup and view all the answers

    What substance is produced from the dissociation of carbonic acid in the bicarbonate buffer system?

    <p>H3O+ and HCO3- (C)</p> Signup and view all the answers

    What do the kidneys primarily regulate in the bicarbonate buffer system?

    <p>HCO3- and H+ ions (C)</p> Signup and view all the answers

    What is a limitation of the carbonic acid buffer system?

    <p>Its buffering ability is limited by the availability of bicarbonate ions. (B)</p> Signup and view all the answers

    Which enzyme is involved in the bicarbonate buffer reactions within the body?

    <p>Carbonic anhydrase (A)</p> Signup and view all the answers

    Which process helps lower blood pH in response to an increase in H3O+ concentration?

    <p>Kidneys excrete bicarbonate. (C)</p> Signup and view all the answers

    What happens to the equilibrium of the bicarbonate buffer system when CO2 levels rise?

    <p>It shifts to produce more H3O+, lowering pH. (A)</p> Signup and view all the answers

    Where is the phosphate buffer primarily found in high concentrations?

    <p>Intracellular fluid (B), Renal tubules (D)</p> Signup and view all the answers

    What is the optimum pH for the phosphate buffer to function effectively?

    <p>6.8 (B)</p> Signup and view all the answers

    Which group of molecules can respond to pH changes by accepting or releasing H+?

    <p>Amino acids (A)</p> Signup and view all the answers

    What does hemoglobin help to transport in addition to CO2?

    <p>Hydrogen and oxygen (C)</p> Signup and view all the answers

    What effect does hyperventilation have on blood pH?

    <p>Raises pH due to removal of H+ (B)</p> Signup and view all the answers

    Which systems are responsible for renal regulation?

    <p>Kidneys and lungs (B)</p> Signup and view all the answers

    What happens during hypoventilation in relation to pH balance?

    <p>Increased H+ causes pH to decrease (C)</p> Signup and view all the answers

    What is a crucial role of the kidneys in maintaining pH balance?

    <p>Conserving and producing bicarbonate ions (D)</p> Signup and view all the answers

    Flashcards

    Water's Unique Properties

    Water has an unusually high boiling point, melting point, heat of vaporization, and surface tension compared to other substances with similar molecular weights. This is because of strong intermolecular forces of attraction between water molecules.

    Water's Density Anomaly

    The maximum density of water occurs in its liquid state, not its solid state (ice). This means that ice floats on water.

    Permanent Dipoles

    A permanent dipole occurs when two atoms in a molecule have significantly different electronegativity. This means one atom attracts electrons more strongly than the other, leading to a partial negative charge on one atom and a partial positive charge on the other.

    Hydrogen Bonding in Water

    Hydrogen bonding arises from the attraction between the partially positive hydrogen atom of one water molecule and the partially negative oxygen atom of another water molecule.

    Signup and view all the flashcards

    Water as a Solvent

    The solvent properties of water are due to its polar nature. Water can dissolve many substances because its polar molecules can surround and pull apart charged or polar molecules.

    Signup and view all the flashcards

    Hydrogen Ion Concentration and Energy

    A difference in hydrogen ion concentration across a membrane represents a form of stored energy. This difference is crucial for biological energy transformations.

    Signup and view all the flashcards

    Water Ionization

    Water molecules are constantly moving and interacting, and some of these interactions cause H2O to ionize (split) into hydrogen ions (H+) and hydroxide ions (OH-).

    Signup and view all the flashcards

    pH Scale

    pH is a measure of the acidity or alkalinity of a solution. It is defined as the negative logarithm (base 10) of the hydrogen ion concentration (H+).

    Signup and view all the flashcards

    Entropy-driven interaction with nonpolar solutes

    The process where nonpolar solutes interact with water molecules, leading to a net decrease in order and an increase in disorder.

    Signup and view all the flashcards

    Amphiphilic molecules

    Molecules that have both strongly polar and strongly nonpolar groups, forming structures like micelles in water.

    Signup and view all the flashcards

    Colligative properties

    Properties of solutions that are primarily affected by the concentration of solute particles, regardless of their chemical nature.

    Signup and view all the flashcards

    Freezing point depression

    The temperature at which a liquid turns into a solid. Solutes decrease the freezing point of water by disrupting the formation of ice crystals.

    Signup and view all the flashcards

    Boiling point elevation

    The temperature at which a liquid turns into a gas. Solutes increase the boiling point of water by making it harder for water molecules to escape into the gas phase.

    Signup and view all the flashcards

    Vapor pressure lowering

    The tendency of a liquid to evaporate. Solutes decrease the vapor pressure of water by reducing the number of water molecules at the surface.

    Signup and view all the flashcards

    Osmotic pressure

    The pressure that must be applied to a solution to prevent the inward flow of water across a semipermeable membrane. Solutes increase the osmotic pressure of water by drawing more water into the solution.

    Signup and view all the flashcards

    Minimizing osmotic pressure in cells

    Cells store substances in polymeric form to minimize osmotic pressure. For example, glycogen or starch exerts less osmotic pressure than individual glucose molecules.

    Signup and view all the flashcards

    Auto-ionization of Water

    The process where water molecules spontaneously ionize into hydrogen ions (H+) and hydroxide ions (OH-) in a reversible reaction. This creates a balance, with a tiny but essential concentration of both ions.

    Signup and view all the flashcards

    Equilibrium

    A state where the rates of forward and reverse reactions are equal, leading to no net change in concentrations of reactants and products.

    Signup and view all the flashcards

    Le Chatelier's Principle

    States that when a stress is applied to a system at equilibrium, the system shifts in a direction that relieves the stress, restoring a new equilibrium.

    Signup and view all the flashcards

    Oxygen-Hemoglobin Equilibrium

    The binding of oxygen to hemoglobin in red blood cells to be transported throughout the body. This is an equilibrium process, with the oxygen binding and releasing depending on oxygen levels.

    Signup and view all the flashcards

    Hypoxia

    A state of oxygen deficiency in the body, often occurring at high altitudes where oxygen levels are lower. Symptoms include headache, fatigue, and shortness of breath.

    Signup and view all the flashcards

    Red Blood Cell Adaptation to Altitude

    The adaptation of the body to low oxygen levels by increasing red blood cell production, thus increasing the amount of hemoglobin available to carry oxygen. This happens at high altitudes.

    Signup and view all the flashcards

    Shift in Equilibrium

    The change in concentrations of reactants and products in a chemical reaction that occurs when a stress is applied to the system at equilibrium.

    Signup and view all the flashcards

    Equilibrium's Resistance to Change

    The ability of a system to oppose changes to its equilibrium state. When a stress is applied, the system will try to minimize the impact.

    Signup and view all the flashcards

    Brønsted-Lowry acid-base pairs

    Brønsted-Lowry acids donate a proton (H+) to form their conjugate base, while Brønsted-Lowry bases accept a proton to form their conjugate acid.

    Signup and view all the flashcards

    Strong acid ionization

    Strong acids ionize completely in water, meaning they donate all their protons, and are represented by a single arrow in chemical equations.

    Signup and view all the flashcards

    Weak acid ionization

    Weak acids ionize partially in water, establishing an equilibrium between the acid and its conjugate base. This is represented by a double arrow in chemical equations.

    Signup and view all the flashcards

    Strong base ionization

    A strong base completely ionizes in water, forming hydroxide ions (OH-), which can accept protons. Strong bases are typically hydroxides of group 1 and 2 metals.

    Signup and view all the flashcards

    pH

    The negative logarithm of the hydronium ion concentration ([H3O+]), used to measure the acidity of a solution.

    Signup and view all the flashcards

    pOH

    The negative logarithm of the hydroxide ion concentration ([OH-]), used to measure the basicity of a solution.

    Signup and view all the flashcards

    pH + pOH = 14

    The relationship between pH and pOH in aqueous solutions, where the sum is always 14.

    Signup and view all the flashcards

    Calculating [H+] from pH

    The molarity of hydrogen ions ([H+]) can be calculated from the pH using the formula: [H+] = 10^(-pH)

    Signup and view all the flashcards

    What are buffers?

    A buffer system resists changes in pH by neutralizing added acids or bases.

    Signup and view all the flashcards

    How does the H2CO3/HCO3- buffer work in the body?

    The H2CO3/HCO3- buffer system, involving carbonic acid and bicarbonate, is a crucial buffer system in body fluids. It helps maintain the pH of blood within a narrow range, crucial for optimal bodily functions.

    Signup and view all the flashcards

    What is acidosis?

    A condition where the blood pH drops below the normal range, often caused by an increase in CO2 levels.

    Signup and view all the flashcards

    What is alkalosis?

    A condition where the blood pH rises above the normal range, often caused by a decrease in CO2 levels.

    Signup and view all the flashcards

    How do the lungs regulate blood pH?

    The lungs play a critical role in regulating blood pH by eliminating CO2. This process is fast and efficient.

    Signup and view all the flashcards

    How do the kidneys regulate blood pH?

    The kidneys help maintain a 20:1 ratio of bicarbonate to carbonic acid in the blood. They can also excrete excess acid or base to regulate blood pH, but this process is slower than the lungs' CO2 elimination.

    Signup and view all the flashcards

    How do the respiratory and urinary systems work together in pH regulation?

    The bicarbonate buffer relies on both the respiratory and urinary systems to function effectively. The respiratory system releases CO2 to lower pH while the kidneys excrete bicarbonate (HCO3-) to lower pH or excrete H+ and release CO2 to raise pH. This interconnected regulation ensures optimal blood pH levels.

    Signup and view all the flashcards

    What are the limitations of the carbonic acid buffer system?

    The carbonic acid buffer system is limited by its reliance on the properly functioning respiratory system and the availability of bicarbonate ions. Additionally, its buffering power is weak due to its pKa being different from the pH of blood.

    Signup and view all the flashcards

    Phosphate Buffer

    This buffer system is effective within cells (ICF) and kidney tubules due to higher phosphate concentrations, optimal pH around 6.8 and the constant production of acidic byproducts of metabolism.

    Signup and view all the flashcards

    Protein Buffers

    Proteins act as buffers by accepting or releasing hydrogen ions (H+) through their amino acid components. Think of it as proteins acting like sponges soaking up excess acid or base.

    Signup and view all the flashcards

    Hemoglobin Buffer

    Hemoglobin is an important protein buffer in the blood. It binds to carbon dioxide, transports oxygen and hydrogen ions, and helps maintain blood pH.

    Signup and view all the flashcards

    Respiratory Buffer

    The lungs are responsible for the elimination of carbon dioxide (CO2), which is a major acid contributor. Increased breathing removes CO2, reducing acidity. It's a fast-acting buffer.

    Signup and view all the flashcards

    Renal Buffer

    The kidneys are the most powerful pH regulator in the body. They can remove fixed acids, conserve and produce bicarbonate ions (HCO3-) and excrete bases from the blood.

    Signup and view all the flashcards

    Hyperventilation and pH

    Rapid breathing (hyperventilation) leads to the removal of CO2, reducing acid levels in the blood and increasing pH .

    Signup and view all the flashcards

    Hypoventilation and pH

    Slow breathing (hypoventilation) leads to the accumulation of CO2, increasing acid levels and lowering pH.

    Signup and view all the flashcards

    Kidney Compensation

    The kidneys compensate for the acid-base balance. They can excrete excess acids, reabsorb bicarbonate, and generate new bicarbonate to neutralize the acids.

    Signup and view all the flashcards

    Study Notes

    Chapter 2: Water: The Medium of Life

    • Life originated, evolved, and thrives in the seas. The timeline of evolution showcases initial aquatic environments, transitioning periods, and the eventual development of terrestrial environments. Key periods such as 395 million years ago (mya) and 340 mya are illustrative of these evolutionary stages.

    • Water and its ionization products (hydrogen ions and hydroxide ions) are crucial for the structure and function of biological molecules (amino acids, proteins, nucleotides, nucleic acids, phospholipids, and membranes).

    • A difference in hydrogen ion concentration on opposite sides of a membrane creates an energized state essential for energy transformation processes in biological systems. This difference is frequently discussed in the context of cellular energy production.

    • Water has unusually high boiling, melting points, heat of vaporization, and surface tension due to strong intermolecular forces of attraction between water molecules. This is anomalously high for substances of similar molecular weight that aren't metallic or ionic.

    • Water's maximum density is found in the liquid state, not the solid state (ice). This means ice occupies more space than liquid water.

    • Permanent dipoles in water molecules occur because of differing electronegativities between oxygen and hydrogen atoms, creating partial charges (δ- and δ+).

    • Hydrogen bonds in water are crucial for its properties. These bonds allow water to participate in a variety of chemical and physical interactions, affecting its behavior and properties.

    2.1 What Are the Properties of Water?

    • Water's high boiling, melting points, heat of vaporization, and surface tension are attributed to the strong intermolecular forces between water molecules. These forces create a significantly ordered structure within liquid water compared to other substances of similar molecular weights which are not metallic nor ionic.

    • Water's unique properties are linked to its polar nature; the uneven distribution of electrons within a water molecule leads to partial charges, forming polar bonds.

    • The solvent properties of water stem from its polar nature. Water readily dissolves many polar and ionic compounds (and some nonpolar) as opposed to other solvents. This is due to its ability to form hydration shells around ions and polar substances.

    • The high dielectric constant of water allows it to weaken the attractive forces between oppositely charged ions, and hydrate them.

    • Water's ability to form hydrogen bonds with polar molecules is crucial for its solvent properties and it is a key driving force in these interactions.

    • Hydrophobic interactions result as nonpolar solutes disrupt the ordered structure of water, and water molecules cluster around them, creating a cage-like structure.

    • Interacting with amphiphilic compounds (having both polar and nonpolar regions) in water results in the formation of micelles; these structures sequester the nonpolar parts from water to maximize entropy.

    2.1 Colligative Properties

    • The presence of dissolved substances affects the properties of water (e.g., freezing point depression, boiling point elevation, vapor pressure lowering, osmotic pressure effects). These effects are the same regardless of the identity of the solute, instead dependent on the concentration of solute in the solution.

    • Solutes increase the order of water molecules surrounding them, making it harder for water to freeze or boil. Solutes also affect osmosis, the movement of water across a selectively permeable membrane.

    2.2 What is pH?

    • pH is a measure of the concentration of hydrogen ions in an aqueous solution. A low pH indicates a high concentration of hydrogen ions, while a high pH indicates a low concentration.

    • pH is described as the power of hydrogen. The pH scale is logarithmic which means that each whole number change in pH represents a tenfold change in H+ concentration.

    • Neutral solutions have an equal concentration of hydrogen and hydroxide ions ([H+]=[OH-]).

    • Acidic solutions have a greater concentration of hydrogen ions than hydroxide ions ([H+] > [OH-]).

    • Basic (or alkaline) solutions have a lower concentration of hydrogen ions than hydroxide ions ([H+] < [OH-]).

    2.3 What are buffers and what do they do?

    • The lungs and kidneys are the main organs regulating pH in body fluids.

    • A buffer helps resist large pH changes. Buffer systems use a conjugate acid-base pair to resist drastic pH changes when hydrogen ions are added or lost to the solution.

    Other Information

    • The ionization constant of water (Kw) relates the concentrations of hydrogen and hydroxide ions to the specific temperature at which it is measured. The value of Kw changes depending on temperature.

    • Strong acids completely dissociate in water, whereas weak acids only partially dissociate. This dissociation leads to different behaviors in solutions of these two different categories of acids.

    • The important buffer systems in the body are the bicarbonate buffer and the phosphate buffer. These act in conjunction with the physiological buffers, the lungs and the kidneys, to maintain the blood pH within a stable range.

    • The respiratory system, by controlling carbon dioxide levels, adjusts the carbonic acid-bicarbonate buffer system. Specifically by altering the rate and depth of breathing.

    • The renal system, through complex processes, regulates and controls the bicarbonate concentration, reabsorption and excretion mechanisms. This is a slow process than lung pH adjustment.

    • The combined action of the lungs and kidneys, along with chemical buffers, work together to help keep pH within a normal range.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Description

    This quiz explores key concepts in biology related to equilibrium, oxygen transport under hypoxia, and the unique properties of water. Dive into questions about reaction rates, altitude adaptation, and the significance of hydrogen and hydroxide ions in biological systems. It's designed for students looking to understand these fundamental scientific principles.

    More Like This

    Equilibrium Chemistry Quiz
    8 questions
    Equilibrium Chemistry Quiz
    23 questions

    Equilibrium Chemistry Quiz

    UnfetteredRockCrystal2181 avatar
    UnfetteredRockCrystal2181
    Use Quizgecko on...
    Browser
    Browser