Chapter 3 A.P. Biology Water Quiz

Water's heat of vaporization is high because it requires a significant amount of energy to convert water from a liquid state to a gaseous state. This is due to the strong hydrogen bonding between water molecules, which results in a high boiling point and a high heat of vaporization. As a result, water can absorb and store a large amount of heat energy, making it an effective coolant and allowing for efficient heat transfer in various natural and industrial processes.

The answer is Cohesion, Adhesion, Surface Tension, High Specific Heat, High Heat of Vaporization, Ice Floats, Universal Solvent. These properties are all characteristics of water that contribute to its unique behavior and importance in biological systems. Cohesion refers to the attraction between water molecules, which allows for surface tension and the ability of water to stick to itself. Adhesion is the attraction between water molecules and other substances, allowing water to adhere to surfaces. Surface tension is the result of cohesive forces at the surface of water. High specific heat and heat of vaporization are properties that allow water to absorb and release heat without significant temperature changes, making it an effective temperature regulator. Ice floats because it is less dense than liquid water. Water is also known as the universal solvent because it has the ability to dissolve a wide variety of substances.

Adhesion refers to the ability of water molecules to stick to other substances. This property is due to the polarity of water molecules, which allows them to form hydrogen bonds with other molecules or surfaces. As a result, water can adhere to various materials such as glass, paper, or plant tissues. This adhesion is important for many biological processes, such as water transport in plants and the ability of water to wet surfaces.

Water has a high specific heat because it requires a large amount of energy to raise its temperature. This means that water can absorb and store a significant amount of heat without experiencing a large increase in temperature. As a result, water is able to regulate temperature and maintain stable conditions in various environments, making it an essential component for many biological processes.

Specific heat refers to the amount of heat energy required to raise the temperature of a substance by a certain amount. In this case, the correct answer states that specific heat is the temperature it takes to raise 1g of a substance by 1 degree Celsius. This means that a specific amount of heat energy is needed to increase the temperature of 1 gram of the substance by 1 degree Celsius.

Water sticks to water is the correct answer because cohesion refers to the attraction between molecules of the same substance. In the case of water, the oxygen atom in one water molecule is attracted to the hydrogen atoms in neighboring water molecules, creating hydrogen bonds. These hydrogen bonds cause water molecules to stick together, resulting in surface tension and other unique properties of water.

The pH scale is used to measure the concentration of H+ ions in a solution. It quantifies the acidity or alkalinity of a solution, with a pH value less than 7 indicating acidity, a value of 7 indicating neutrality, and a value greater than 7 indicating alkalinity. By measuring the concentration of H+ ions, the pH scale provides a standardized way to compare the acidity or alkalinity of different solutions.

A buffer is a substance that resists changes in pH. It is able to maintain a relatively stable pH even when small amounts of acid or base are added. Buffers typically consist of a weak acid and its conjugate base, or a weak base and its conjugate acid. These components can react with any added acid or base, preventing significant changes in pH. Buffers are important in biological systems, as they help maintain the pH necessary for proper functioning of enzymes and other molecules.

The normal pH of blood is 7.2 - 7.4. pH is a measure of the acidity or alkalinity of a solution, with a pH of 7 being neutral. The pH range of 7.2 - 7.4 indicates that blood is slightly alkaline or basic. This pH range is important for maintaining the proper functioning of enzymes and other biological processes in the body. Deviations from this normal range can lead to health issues such as acidosis or alkalosis.

Water is a polar molecule, meaning it has a slight positive charge on one end and a slight negative charge on the other. This polarity allows water molecules to attract and surround ions or polar molecules, causing them to dissolve. Therefore, water acts as a universal solvent for substances that are ionic or polar covalent in nature, dissolving them in most solutions.

Water molecules are held together by hydrogen bonds. These bonds form between the hydrogen atom of one water molecule and the oxygen atom of another water molecule. Hydrogen bonds are weaker than covalent bonds but stronger than other intermolecular forces, such as van der Waals forces. These bonds give water its unique properties, such as high boiling point, surface tension, and the ability to dissolve many substances.

Water on Earth regulates the Earth's temperature by absorbing heat. When the sun's rays reach the Earth's surface, water absorbs a significant amount of this heat energy. However, water has a high specific heat capacity, meaning it can absorb a large amount of heat energy without undergoing a significant increase in temperature. This property allows water to act as a buffer, preventing rapid temperature fluctuations in the Earth's climate. As a result, water helps to regulate and stabilize the Earth's temperature, creating a more habitable environment for living organisms.

One defining feature of acids is that they give off H+ ions. This is because acids are substances that can donate protons (H+) to a solution. When an acid is dissolved in water, it releases H+ ions, which contribute to the acidic properties of the solution. The concentration of H+ ions determines the acidity of the solution, with higher concentrations indicating stronger acids.

Water is made up of positive H ions (hydrogen ions) and negative OH ions (hydroxide ions). The positive H ions are formed when water molecules lose an electron, while the negative OH ions are formed when water molecules gain an electron. These ions combine to form water molecules, with the H ions bonding with the oxygen atom in the OH ions. Therefore, both positive H ions and negative OH ions are present in water.

Surface tension is a phenomenon that occurs when water molecules at the surface of a body of water are attracted to each other more strongly than to the air molecules above. This attraction causes the water molecules to form a cohesive "skin" on the surface, giving it a higher level of tension compared to the bulk of the water. This "skin" allows certain objects to float on the surface of water and allows insects, like water striders, to walk on water.

Normal rain is made of water and carbon dioxide (carbonic acid) because when water vapor in the atmosphere condenses, it combines with carbon dioxide to form carbonic acid. This is a natural process that occurs due to the presence of carbon dioxide in the air.

Acid rain is formed when pollutants such as sulfur dioxide and nitrogen oxides react with the atmosphere. These pollutants dissolve in rainwater, forming sulfuric acid and nitric acid, which lower the pH of the rainwater. A pH value below 5.2 indicates that the rainwater is acidic, confirming that the correct answer is less than 5.2.

Water's high specific heat allows it to absorb and release heat without undergoing significant temperature changes. This property stabilizes climates and environments, ensuring that temperature fluctuations are minimized, which is crucial for maintaining conditions suitable for life on Earth. The buffering effect helps sustain aquatic ecosystems and regulates temperature in organisms and the planet overall.

The heat of vaporization is the amount of heat energy required to convert 1 gram of a substance from a liquid to a gas at its boiling point. It is measured in units of energy per unit mass, such as joules per gram (J/g) or calories per gram (cal/g). The answer choice "The temperature in Celsius to boil 1g of a substance at boiling point" correctly describes the heat of vaporization as the temperature required to boil 1 gram of a substance at its boiling point.

The primary function of perspiration (sweating) in the human body is to regulate body temperature. When the body heats up, sweat glands release sweat onto the surface of the skin. As this sweat evaporates, it cools the body down, helping to maintain a stable internal temperature. Although perspiration can also help eliminate some waste products, it plays a minimal role in detoxification. Its main purpose is thermoregulation rather than hormone production or enhancing skin elasticity.

Hydronium ions (H3O+) can supplement for H+ ions because they are formed when a water molecule (H2O) gains an extra proton (H+). This proton is then attached to the oxygen atom in the water molecule, resulting in the formation of a hydronium ion. Therefore, hydronium ions can act as a source of H+ ions in chemical reactions and can play a similar role in acid-base reactions.

As pH increases, the concentration of hydrogen ions ([H+]) decreases. This is because pH is a measure of the acidity or alkalinity of a solution, with a lower pH indicating higher acidity and a higher concentration of hydrogen ions. Therefore, as pH increases, the solution becomes more alkaline and the concentration of hydrogen ions decreases. Conversely, as pH decreases, the solution becomes more acidic and the concentration of hydrogen ions increases. Therefore, both statements A and C are true.

Water's heat of vaporization is the amount of heat energy required to convert a given quantity of water from its liquid state to its gaseous state at a constant temperature and pressure. It is a measure of the strength of the intermolecular forces between water molecules. The correct answer, 2260 Joules, indicates that a significant amount of energy is needed to overcome these forces and vaporize water.

The correct answer is either B or C because acid rain is made of water combined with either sulfate (forming sulfuric acid) or nitrate (forming nitric acid). Acid rain is a result of air pollution, particularly from the burning of fossil fuels, which releases sulfur dioxide and nitrogen oxides into the atmosphere. These gases react with water vapor in the air to form sulfuric acid or nitric acid, which then falls to the earth as acid rain.

The pH scale measures the acidity or basicity of a substance. A pH of 3 indicates that the substance is acidic. The concentration of OH- ions in an acidic solution is very low. As the pH decreases, the concentration of OH- ions decreases exponentially. Therefore, a substance with a pH of 3 would have an OH- concentration of 10^-11.

One can measure OH- concentration using the pOH scale. The pOH scale is the negative logarithm of the concentration of OH- ions in a solution. It is used to measure the basicity or alkalinity of a solution, just like the pH scale is used to measure acidity. By measuring the pOH of a solution, one can determine the concentration of OH- ions present. Therefore, the correct answer is the pOH scale.

Normal rain has a pH of 5.6. This means that it is slightly acidic. Rainwater becomes acidic due to the presence of carbon dioxide in the atmosphere, which reacts with water to form carbonic acid. The pH scale ranges from 0 to 14, with values below 7 indicating acidity. A pH of 5.6 suggests that the rainwater is mildly acidic but still within the range of what is considered normal for rain.

As water cools, the molecules slow down and come closer together. This closer proximity allows the water molecules to form more hydrogen bonds with each other. These hydrogen bonds create a lattice-like structure in the water molecules, which causes them to spread out and become less dense. This decrease in density makes ice less dense than liquid water, causing it to float.