1.
The energy a substance uses or releases to change phase.
Correct Answer
A. Latent heat
Explanation
Latent heat refers to the energy that a substance either uses or releases when it undergoes a phase change, such as from solid to liquid or liquid to gas. This energy is not associated with a change in temperature but rather with the change in the substance's state. It is called "latent" because it is hidden or concealed within the substance and is not easily detectable. Therefore, latent heat is the correct answer to the given question.
2.
The MOST reliable way to find a pH level is with _______________.
Correct Answer
D. A pH meter
Explanation
A pH meter is the most reliable way to find a pH level because it directly measures the concentration of hydrogen ions in a solution. It provides a precise and accurate reading of the pH value, allowing for more precise analysis and control of pH levels. Litmus paper can give a rough estimate of pH but is not as accurate as a pH meter. Anthocyanins are pigments found in plants and are not used for measuring pH. A pH scale is a reference tool that shows the range of pH values but does not provide an actual measurement.
3.
Blood is kept at a healthy, slightly basic pH by ___________.
Correct Answer
C. Various buffering agents in the blood
Explanation
The correct answer is various buffering agents in the blood. Buffering agents in the blood help maintain a stable pH by neutralizing any excess acids or bases. These agents include bicarbonate ions, proteins, and phosphates. They can accept or donate hydrogen ions, depending on whether the blood becomes too acidic or too basic. This ensures that the blood pH remains within a narrow range, which is essential for proper functioning of enzymes and other biological processes.
4.
On the pH scale, ___________________.
Correct Answer
B. Lower values indicate greater acidity
Explanation
On the pH scale, lower values indicate greater acidity. This is because the pH scale is logarithmic, meaning that each unit represents a tenfold difference in acidity or alkalinity. A lower pH value indicates a higher concentration of hydrogen ions, which is characteristic of acidic solutions. Higher values on the pH scale, on the other hand, indicate a lower concentration of hydrogen ions and are associated with alkaline or basic solutions. Therefore, the correct answer is that lower values on the pH scale indicate greater acidity.
5.
A base in which few molecules ionize is called _______________.
Correct Answer
A. Weak
Explanation
A base in which few molecules ionize is called weak. This means that only a small fraction of the base molecules dissociate into ions when dissolved in water. In contrast, a strong base would completely ionize and dissociate into ions when dissolved in water. Therefore, the correct answer is weak.
6.
One sign that neutralization has occurred is _______________.
Correct Answer
C. The presence of water
Explanation
The presence of water is a sign that neutralization has occurred because neutralization is a chemical reaction between an acid and a base, resulting in the formation of a salt and water. Therefore, the presence of water indicates that the acid and base have reacted and neutralized each other.
7.
Acids in foods pose little health risk because __________________________.
Correct Answer
B. They are weak
Explanation
Acids in foods pose little health risk because they are weak. Weak acids are less likely to cause harm or damage to the body compared to strong acids. They have a lower concentration of hydrogen ions, making them less corrosive and less likely to cause irritation or tissue damage. Therefore, consuming foods that contain weak acids is generally safe and does not pose significant health risks.
8.
Hydrogen ions and hydroxide ions ________________.
Correct Answer
D. All are true
Explanation
Hydrogen ions and hydroxide ions carry opposite charges and are products of ionization. Additionally, they have the ability to combine to form water. Therefore, all of the given statements are true.
9.
Five liters of a 3 M solution of ammonia contains _________________.
Correct Answer
D. 15 moles of ammonia
Explanation
A 3 M solution means that there are 3 moles of ammonia dissolved in 1 liter of solution. Since we have 5 liters of solution, we can multiply the concentration by the volume to find the number of moles of ammonia present. Therefore, 3 moles/L * 5 L = 15 moles of ammonia in the solution.
10.
A base in solution ________________.
Correct Answer
A. Produces hydroxide ions
Explanation
A base in solution produces hydroxide ions. When a base is dissolved in water, it dissociates and releases hydroxide ions (OH-) into the solution. These hydroxide ions then react with hydrogen ions (H+) to form water molecules, thereby increasing the concentration of hydroxide ions in the solution. This increase in hydroxide ion concentration leads to an increase in pH, making the solution more basic. Therefore, the correct answer is that a base in solution produces hydroxide ions.
11.
To do a titration of an acid solution, you need to know _________________.
Correct Answer
D. All are true
Explanation
To do a titration of an acid solution, it is necessary to know the volume of the acid solution, as this is the solution being titrated. Additionally, the volume of a basic solution is required, as this is the solution being added to the acid solution during the titration process. Lastly, the concentration of the basic solution is needed, as it allows for the calculation of the amount of acid that has reacted. Therefore, all of these statements are true and essential for performing a titration of an acid solution.
12.
Having an equal number of hydrogen atoms and hydrogen ions.
Correct Answer
A. Neutral
Explanation
A solution is considered neutral when it has an equal number of hydrogen ions (H+) and hydroxide ions (OH-). In this context, having an equal number of hydrogen atoms and hydrogen ions would mean that the solution is neutral. The terms "molarity," "base," and "acid" are not directly related to the given explanation and can be disregarded.
13.
A stage of titration that indicates neutralization
Correct Answer
A. Equivalence point
Explanation
The equivalence point is the stage of titration where the amount of acid and base being reacted is stoichiometrically equivalent. At this point, all the hydrogen ions from the acid and hydroxide ions from the base have reacted to form water. The indicator used in the titration changes color at the equivalence point, indicating that neutralization has occurred. Therefore, the equivalence point is the stage of titration that indicates neutralization.
14.
A procedure done to determine the molarity of a solution
Correct Answer
A. Titration
Explanation
Titration is the correct answer because it is a procedure used to determine the molarity or concentration of a solution. In titration, a known concentration of a solution, called the titrant, is slowly added to a solution of unknown concentration, called the analyte, until the reaction between the two is complete. By measuring the volume of titrant required to reach the endpoint of the reaction, the molarity or concentration of the analyte can be calculated. Tonsilectomy is unrelated to determining the molarity of a solution and is therefore not the correct answer.
15.
A measure of relative acidity in a solution
Correct Answer
A. pH
Explanation
pH is a measure of the relative acidity or alkalinity of a solution. It indicates the concentration of hydrogen ions present in the solution. A lower pH value indicates higher acidity, while a higher pH value indicates higher alkalinity. pH is measured on a scale ranging from 0 to 14, with 7 being considered neutral. Therefore, pH is the correct answer as it directly relates to measuring the acidity of a solution.
16.
A substance that releases hydrogen ions in a solution
Correct Answer
A. Acid
Explanation
An acid is a substance that releases hydrogen ions in a solution. This means that when an acid is dissolved in water, it dissociates and releases hydrogen ions (H+). These hydrogen ions make the solution acidic. Acids are known for their sour taste and ability to react with metals and bases. Examples of common acids include hydrochloric acid (HCl) and sulfuric acid (H2SO4).
17.
A positively charged particle
Correct Answer
A. Hydrogen ion
Explanation
A hydrogen ion is a positively charged particle that consists of a single proton. In solution, it is often represented as H+. Hydrogen ions play a crucial role in many chemical reactions, particularly in acidic solutions. They are involved in processes such as acid-base reactions, titrations, and the formation of salts. In biological systems, hydrogen ions also help regulate pH levels and are important for the functioning of enzymes and other proteins. Therefore, the given answer "hydrogen ion" is correct.
18.
A substance that responds to pH by changing color
Correct Answer
A. Indicator
Explanation
An indicator is a substance that can be used to determine the pH of a solution by changing color. It is typically a weak acid or base that undergoes a color change when it reacts with acidic or basic solutions. Indicators are commonly used in chemistry and biology experiments to determine the acidity or alkalinity of a solution.
19.
A measurement that tells the amount of a substance per unit of volume
Correct Answer
A. Concentration
Explanation
Concentration is the correct answer because it refers to the measurement of the amount of a substance per unit of volume. It is a way to express the relative amount of solute in a solution or the strength of a solution. Concentration can be measured in various units such as molarity, percent by volume, or parts per million. It is an important concept in chemistry and is used to determine the properties and behavior of solutions.
20.
A result of a hydrogen ion and hydroxide ion bonding
Correct Answer
A. Water
Explanation
When a hydrogen ion (H+) and a hydroxide ion (OH-) bond together, they form a water molecule (H2O). This is a neutral substance because the positive charge of the hydrogen ion is balanced by the negative charge of the hydroxide ion. Therefore, the correct answer is water.
21.
A substance that releases hydroxide ions in solution
Correct Answer
A. Base
Explanation
A base is a substance that releases hydroxide ions in solution. When a base is dissolved in water, it dissociates into hydroxide ions (OH-) and a positive ion. These hydroxide ions can react with hydrogen ions (H+) from an acid to form water. Bases are known for their ability to neutralize acids and have a pH greater than 7.
22.
A measurement that indicates the moles of solute per liter of solution
Correct Answer
A. Molarity
Explanation
Molarity is a measurement that indicates the moles of solute per liter of solution. It is a unit of concentration commonly used in chemistry. By knowing the molarity, one can determine the amount of solute present in a given volume of solution. This measurement is important in various chemical reactions and calculations, as it helps in determining the stoichiometry and making accurate dilutions. Therefore, molarity is the correct answer to the given question.
23.
A substance that prevents blood from becoming too acidic or basic
Correct Answer
A. Buffer
Explanation
A buffer is a substance that helps maintain the pH level of a solution by preventing it from becoming too acidic or basic. It achieves this by accepting or donating protons (H+) to maintain a stable pH. In other words, a buffer acts as a "sponge" for excess hydrogen ions, preventing drastic changes in pH. Therefore, a buffer is the correct answer for a substance that prevents blood from becoming too acidic or basic.
24.
A chemical reaction that produces water and salts
Correct Answer
A. Neutralization
Explanation
Neutralization is the correct answer because it refers to a chemical reaction that occurs when an acid and a base react to form water and a salt. This reaction involves the transfer of protons from the acid to the base, resulting in the formation of water and a compound known as a salt. Neutralization reactions are commonly used in various applications, such as in the production of medicines, the treatment of acidic soil, and the neutralization of stomach acids.
25.
A plant pigment used to test pH
Correct Answer
A. Anthocyanin
Explanation
Anthocyanin is a plant pigment that is commonly used to test pH levels. It changes color depending on the acidity or alkalinity of the solution it is in. This makes it a useful indicator for determining the pH of a substance. Acid, buffer, and titration are all related terms but do not specifically refer to a plant pigment used for pH testing.
26.
A substance with a pH value of 3.4 is more _______________________ than one with a value of 7.8
Correct Answer
A. Acidic
Explanation
A substance with a pH value of 3.4 is more acidic than one with a value of 7.8. pH is a measure of the acidity or alkalinity of a substance on a scale of 0-14. A pH value below 7 indicates acidity, and as the pH value decreases, the acidity increases. Therefore, a substance with a pH of 3.4 is more acidic than a substance with a pH of 7.8, which is close to neutral.
27.
Dissolving two moles of solute in one liter of solvent gives you a solution with a(n) ________________ of 2.0.
Correct Answer
A. Molarity
Explanation
When two moles of solute are dissolved in one liter of solvent, the resulting solution has a molarity of 2.0. Molarity is a measure of the concentration of a solution and is defined as the number of moles of solute per liter of solvent. In this case, since two moles of solute are dissolved in one liter of solvent, the molarity is 2.0.
28.
Because basic foods take longer to dissolve in the mouth, their _______________ taste tends to linger on the taste buds.
Correct Answer
A. Bitter
Explanation
Basic foods, such as bitter ones, take longer to dissolve in the mouth. This extended contact with the taste buds allows the taste of bitterness to linger on the tongue. Therefore, the correct answer is "bitter."
29.
A basic solution contains a high proportion of ___________________.
Correct Answer
A. Hydroxide ions
Explanation
A basic solution contains a high proportion of hydroxide ions. This is because hydroxide ions, OH-, are responsible for the basic properties of a solution. In a basic solution, the concentration of hydroxide ions is higher compared to the concentration of hydrogen ions (H+). The presence of hydroxide ions allows the solution to neutralize acids and increase the pH level. Therefore, a high proportion of hydroxide ions is indicative of a basic solution.
30.
The description "5 g of sodium per liter" refers to the _________________________.
Correct Answer
A. Concentration
Explanation
The description "5 g of sodium per liter" refers to the concentration of sodium in the solution. Concentration refers to the amount of a substance present in a given volume of a solution. In this case, it indicates that there are 5 grams of sodium dissolved in every liter of the solution.
31.
___________________________ of water, in which molecules separate into hydrogen and hydroxide ions, occurs in a small percentage of water molecules.
Correct Answer
A. Ionization
Explanation
Ionization is the process in which water molecules separate into hydrogen and hydroxide ions. This occurs in a small percentage of water molecules.
32.
A solution reaches its ________________ point when a base and acid contribute equal number of ions.
Correct Answer
A. Equivalence
Explanation
When a solution reaches its equivalence point, it means that the base and acid in the solution have reacted in such a way that they contribute an equal number of ions. This is often achieved through a process called neutralization, where the acid and base react to form a salt and water. Titration is a common method used to determine the equivalence point in a chemical reaction. Concentration, on the other hand, refers to the amount of solute present in a given volume of solution and is not directly related to the equivalence point.
33.
A(n) _________________ solution has a one-to-one ratio of hydrogen ions to hydroxide ions.
Correct Answer
A. Neutral
Explanation
A neutral solution has a one-to-one ratio of hydrogen ions to hydroxide ions. This means that the concentration of hydrogen ions (H+) is equal to the concentration of hydroxide ions (OH-), resulting in a balanced pH level of 7. In a neutral solution, the number of acidic and basic ions are equal, creating a state of equilibrium.
34.
The sensitivity to pH makes red cabbage a natural ___________________________.
Correct Answer
A. Indicator
Explanation
The sensitivity to pH refers to the ability of red cabbage to change color in response to changes in acidity or alkalinity. This property makes red cabbage a natural indicator, as it can be used to determine the pH of a solution by observing the color change.
35.
A basic, 2 M solution could be used to carry out the ________________ of a solution of unknown acidity.
Correct Answer
A. Titration
Explanation
A basic, 2 M solution could be used to carry out the titration of a solution of unknown acidity. Titration is a process in which a solution of known concentration (in this case, a basic solution with a concentration of 2 M) is slowly added to a solution of unknown concentration (the solution of unknown acidity) until a reaction between the two solutions is complete. By measuring the volume of the known solution required to react completely with the unknown solution, the concentration of the unknown solution can be determined.
36.
The ______________ of acids and bases describes the percentage of molecules that form ions in acidity.
Correct Answer
A. Strength
Explanation
The term "strength" refers to the ability of acids and bases to form ions in acidity. It describes the percentage of molecules that dissociate into ions when the substance is dissolved in water. A strong acid or base will fully dissociate into ions, while a weak acid or base will only partially dissociate. Therefore, the strength of an acid or base determines its ability to contribute to the acidity of a solution.
37.
An acid breaks down into _______________ in solution.
Correct Answer
A. Hydrogen ions
Explanation
When an acid is dissolved in a solution, it dissociates or breaks down into hydrogen ions. This is because acids are substances that release hydrogen ions (H+) when dissolved in water. These hydrogen ions are responsible for the acidic properties of the solution. Therefore, the correct answer is hydrogen ions.
38.
Any solution becomes more ______________ as you add solute.
Correct Answer
A. Concentrated
Explanation
As you add solute to a solution, the amount of solute particles increases relative to the solvent particles. This leads to a higher concentration of solute in the solution, making it more concentrated. Therefore, the correct answer is "concentrated".
39.
______________ occurs when caids and bases mixed in solutions each "cancel out" the effects of the other.
Correct Answer
A. Neutralization
Explanation
Neutralization occurs when acids and bases are mixed in solutions and their effects cancel out each other. This process involves the transfer of protons from the acid to the base, resulting in the formation of water and a salt. The pH of the solution becomes neutral, around 7, indicating that the concentration of H+ and OH- ions are equal. This reaction is commonly used to neutralize the acidity or alkalinity of a solution and is important in various applications, such as in the pharmaceutical industry and in the human body to maintain proper pH levels.
40.
Because it creates your first impression, a food's ___________________ can affect whether you like it before you taste it.
Correct Answer
A. Appearance
Explanation
FCS-FS 2 d. Discuss factors affecting a person’s food preference such as physical, psychological, cultural, and environmental influences.
41.
A solution is:
Correct Answer
B. A homogeneous mixture in which one substance is disolved in another
Explanation
FCS-FS-3. Students will discuss the basic chemistry concepts of food science.
b. Describe solutions, heterogeneous mixtures, and homogeneous mixtures and explain their similarities and differences.
42.
____________________________ applies science to food choices, to identify and develop those traits that make a food appealing.
Correct Answer
C. Sensory evaluation
Explanation
FCS-FS-12 d. Discuss factors affecting a person’s food preference such as physical, psychological, cultural, and environmental influences.
43.
An illness that leaves a person ____________________can make food seem flavorless, discouraging good nutrition when needed most.
Correct Answer
C. Taste blind
Explanation
FCS-FS 2 b. Define sensory evaluation, identify the qualities that make-up the sensory characteristics of food, and explain how taste, aroma and mouth sensations combine to give food their flavor.
44.
To get a reaction to a new food item from people who might buy it, manufacturers consult ________________________ panels,
Correct Answer
B. Consumer
Explanation
FCS-FS 2 a. Identify physical, physicochemical, and chemical techniques used for assessing food quality.
45.
The way a food _________________________ when you eat it affects your perception of how it feels.
Correct Answer
C. Sounds
Explanation
FCS-FS b. Define sensory evaluation, identify the qualities that make-up the sensory characteristics of food, and explain how taste, aroma and mouth sensations combine to give food their flavor.
46.
Sweet and sour are two of the sensations detected by the ______________________________.
Correct Answer
D. Taste buds
Explanation
FCS-FS-2 b. Define sensory evaluation, identify the qualities that make-up the sensory characteristics of food, and explain how taste, aroma and mouth sensations combine to give food their flavor.
47.
Member of a(n) ________________________panel judge a food from a unique perspective, since they are the ones who helped develop the product.
Correct Answer
B. Laboratory
Explanation
FCS-FS 2 c. Explain what sensory evaluation panels do and conduct a sensory panel using appropriate controls; quantify and analyze the data.
48.
Through __________________________________, food technologists measure food traits with a scientific precision that most people are not capable of.
Correct Answer
A. Object evaluation
Explanation
FCS-FS 2 e. Describe the role of science in the development of new food products and the use of the scientific method.
49.
An atom is to an element as a ________________.
Correct Answer
B. Molecule is to a compound
Explanation
FCS-FS-3 e. Compare and contrast elements and compounds and explain the difference between ionic and covalent bonds and compounds.
50.
Steam rising from a bowl of hot soup is considered a solution because it _____________________.
Correct Answer
A. Contains food molecules dissolved in gases
Explanation
FCS-FS-3 b. Describe solutions, heterogeneous mixtures, and homogeneous mixtures and explain their similarities and differences.