1.
The MOST reliable way to find a pH level is with _______________.
Correct Answer
A. 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, allowing for more precise adjustments and control of pH levels. Litmus paper can only provide a rough estimate and is less accurate. Anthocyanins are pigments found in plants and have no direct relation to measuring pH levels. A pH scale is a reference tool that helps in understanding pH levels but does not provide an actual measurement.
2.
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 excess acids or bases. These agents include bicarbonate ions, proteins, and phosphates. They prevent drastic changes in pH that could be harmful to the body's cells and organs. This balance is crucial for the proper functioning of enzymes, proteins, and other cellular processes.
3.
On the pH scale, ___________________.
Correct Answer
B. Lower values indicate greater acidity
Explanation
On the pH scale, lower values indicate greater acidity. The pH scale measures the acidity or alkalinity of a substance, with values ranging from 0 to 14. A pH value below 7 is considered acidic, and as the value decreases, the acidity increases. Therefore, lower values on the pH scale indicate greater acidity.
4.
A base in which few molecules ionize is called _______________.
Correct Answer
A. Weak
Explanation
A base in which few molecules ionize is called weak because it does not fully dissociate into ions in solution. This means that only a small fraction of the base molecules break apart into ions, resulting in a lower concentration of ions in the solution compared to a strong base.
5.
One sign that neutralization has occurred is _______________.
Correct Answer
C. The presence of water
Explanation
Neutralization is a chemical reaction that occurs when an acid and a base react to form a salt and water. Water is always produced as a result of this reaction. Therefore, the presence of water indicates that neutralization has occurred.
6.
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 do not ionize completely in water, which means they release fewer hydrogen ions and have a lower acidity level. This lower acidity level makes them less harmful to the body when consumed in moderate amounts. Strong acids, on the other hand, can cause tissue damage and other health issues if ingested. Therefore, the fact that the acids in foods are weak helps to ensure that they do not pose a significant health risk.
7.
A base in solution ________________.
Correct Answer
A. Produces hydroxide ions
Explanation
When a base is dissolved in a solution, it produces hydroxide ions (OH-). These hydroxide ions then react with hydrogen ions (H+) present in the solution, leading to the formation of water molecules. This process is known as neutralization, where the base neutralizes the solution by balancing the pH. Therefore, the correct answer is that a base in solution produces hydroxide ions.
8.
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, the volume of a basic solution, and the concentration of the basic solution. The volume of the acid solution is important to determine the stoichiometry of the reaction and calculate the amount of acid present. The volume of the basic solution is needed to determine the equivalence point of the reaction. Lastly, the concentration of the basic solution is essential to calculate the molarity of the acid solution. Therefore, all the given statements are true for a successful titration of an acid solution.
9.
Having an equal number of hydrogen atoms and hydrogen ions.
Correct Answer
A. Neutral
Explanation
When the number of hydrogen atoms and hydrogen ions is equal, the solution is considered to be neutral. In a neutral solution, the concentration of hydrogen ions (H+) is equal to the concentration of hydroxide ions (OH-), resulting in a balanced pH level. This means that the solution is neither acidic nor basic.
10.
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 have been neutralized by the hydroxide ions from the base, resulting in the formation of water. Therefore, the equivalence point indicates neutralization.
11.
A procedure done to determine the molarity of a solution
Correct Answer
A. Titration
Explanation
Titration is a procedure used to determine the molarity or concentration of a solution. It involves adding a known solution of one substance (the titrant) to a known volume of another solution (the analyte) until a reaction between the two is complete. By measuring the volume of titrant required to reach the endpoint of the reaction, the molarity of the analyte solution can be calculated. This method is commonly used in chemistry laboratories to determine the concentration of acids, bases, or other substances in a solution.
12.
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 (H+) present in the solution. A lower pH value indicates a higher concentration of hydrogen ions, making the solution more acidic. On the other hand, a higher pH value indicates a lower concentration of hydrogen ions, making the solution more alkaline. pH is commonly used in various fields, including chemistry, biology, and environmental science, to determine the acidity or alkalinity of substances and solutions.
13.
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 donates hydrogen ions (H+) to the solution. These hydrogen ions make the solution more acidic. Acids have a pH value less than 7 and can react with bases to form salts and water.
14.
A positively charged particle
Correct Answer
A. Hydrogen ion
Explanation
A hydrogen ion is a positively charged particle that is formed when a hydrogen atom loses its electron. In chemistry, hydrogen ions play a crucial role in various reactions and processes. They are often involved in acid-base reactions and can determine the pH of a solution. Hydrogen ions are also important in titrations, which are used to determine the concentration of an unknown substance. Additionally, hydrogen ions can affect the color of certain compounds, such as anthocyanins, which are responsible for the vibrant colors in many fruits and flowers.
15.
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. When an indicator is added to a solution, it reacts with the hydrogen ions (H+) or hydroxide ions (OH-) present, causing a color change that can be used to determine the acidity or alkalinity of the solution. This property makes indicators useful in various applications, such as in chemistry experiments, medical tests, and quality control processes.
16.
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 quantitative measure that indicates how much of a solute is dissolved in a solvent. Concentration can be expressed 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 strength or dilution of a solution.
17.
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 water (H2O). This reaction is known as neutralization, where an acid and a base react to produce a neutral substance. In this case, the hydrogen ion is from the acid and the hydroxide ion is from the base, and their combination results in the formation of water, which is a neutral substance. Therefore, the correct answer is water.
18.
A substance that releases hydroxide ions in solution
Correct Answer
A. Base
Explanation
A base is a substance that releases hydroxide ions in solution. This means that when the base is dissolved in water, it will dissociate and release hydroxide ions (OH-) into the solution. Bases are known for their ability to neutralize acids and have a pH value greater than 7. They can also react with acids to form water and a salt. Examples of bases include sodium hydroxide (NaOH) and calcium hydroxide (Ca(OH)2).
19.
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 to express the amount of solute dissolved in a given amount of solvent. Molarity is calculated by dividing the number of moles of solute by the volume of the solution in liters. It is an important concept in many chemical calculations and is used to determine the amount of reactants required in a chemical reaction or to calculate the concentration of a solution.
20.
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 of a solution by resisting changes in acidity or alkalinity. It can prevent the blood from becoming too acidic or basic by absorbing or releasing hydrogen ions (H+) to maintain a stable pH level. Buffers are important in biological systems as they help regulate the pH and ensure that essential biological processes can occur within a narrow pH range.
21.
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. In this reaction, the acidic and basic properties of the reactants are neutralized, resulting in the formation of a neutral product. This process is commonly used in various applications, such as in the treatment of acidic wastewater or in the preparation of neutral solutions for laboratory experiments.
22.
A plant pigment used to test pH
Correct Answer
A. Anthocyanin
Explanation
Anthocyanin is a plant pigment that can be used to test pH because it changes color depending on the acidity or alkalinity of the solution. In acidic conditions, anthocyanin appears red, while in alkaline conditions it appears blue or purple. This property makes it a useful indicator for determining the pH of a solution. Acid, buffer, and titration are not specifically related to plant pigments or pH testing, so they are not the correct answer in this context.
23.
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, with values below 7 indicating acidity. Therefore, a substance with a pH of 3.4 is more acidic than a substance with a pH of 7.8, which is closer to neutral.
24.
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.
25.
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-tasting ones, take longer to dissolve in the mouth. This means that their taste molecules have more time to interact with the taste buds on the tongue, resulting in a lingering bitter taste sensation.
26.
A basic solution contains a high proportion of ___________________.
Correct Answer
A. Hydroxide ions
Explanation
A basic solution contains a high proportion of hydroxide ions. In chemistry, a solution is considered basic when it has a pH greater than 7. Hydroxide ions (OH-) are responsible for the basic nature of a solution. They are formed when a base dissolves in water and release hydroxide ions. The higher the concentration of hydroxide ions in a solution, the more basic it is. Therefore, a basic solution contains a high proportion of hydroxide ions.
27.
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. Concentration is a measure of the amount of a substance dissolved in a given volume of solution. In this case, it is indicating that there are 5 grams of sodium dissolved in each liter of solution.
28.
___________________________ 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 refers to the process in which water molecules separate into hydrogen and hydroxide ions. This process occurs in only a small percentage of water molecules.
29.
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 contributed an equal number of ions. This indicates that the reaction between the base and acid is complete and the solution is neutralized. The term "equivalence" refers to the point at which the reactants have been consumed in stoichiometric amounts, resulting in a balanced chemical equation. This is commonly observed in titration experiments, where a known concentration of one solution is gradually added to another until the equivalence point is reached.
30.
A(n) _________________ solution has a one-to-one ratio of hydrogen ions to hydroxide ions.
Correct Answer
A. Neutral
Explanation
A neutral solution has an equal concentration of hydrogen ions (H+) and hydroxide ions (OH-), resulting in a one-to-one ratio. This means that the solution is neither acidic nor basic, as it does not have an excess of either hydrogen ions or hydroxide ions. The term "totalitarian" is unrelated to the concept of pH and does not apply to this question.
31.
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 different levels of acidity or alkalinity. This characteristic makes it a natural indicator, as it can be used to determine the pH of a solution by observing the color change. A buffer is a solution that resists changes in pH, titration is a process of determining the concentration of a substance in a solution, and sugar does not have any relevance to the sensitivity to pH of red cabbage.
32.
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 technique used in chemistry to determine the concentration of an unknown solution by reacting it with a solution of known concentration (in this case, a basic 2 M solution). By carefully measuring the volume of the known solution required to neutralize the unknown solution, the acidity or alkalinity of the unknown solution can be determined.
33.
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 extent or degree of acidity or basicity of a solution. In the context of acids and bases, it describes the percentage of molecules that dissociate into ions when dissolved in water. A strong acid or base is one that completely ionizes, meaning a high percentage of its molecules form ions in solution.
34.
An acid breaks down into _______________ in solution.
Correct Answer
A. Hydrogen ions
Explanation
When an acid dissolves in solution, it releases hydrogen ions (H+). These hydrogen ions are responsible for the acidic properties of the solution. Therefore, the correct answer is hydrogen ions.
35.
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 in relation to the solvent. This leads to a higher concentration of solute in the solution, making it more concentrated. Therefore, the correct answer is "concentrated".
36.
______________ 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 on each other are canceled out. This is because acids release hydrogen ions (H+) while bases release hydroxide ions (OH-). When these ions combine, they form water (H2O) and a salt. This reaction results in a neutral pH, hence the term "neutralization".
37.
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.
38.
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.
39.
____________________________ 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.
40.
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.
41.
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.
42.
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.
43.
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.
44.
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.
45.
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.
46.
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.
47.
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.
48.
Melting and boiling points are Most related to a substance's ________________.
Correct Answer
C. pHase
Explanation
FCS-FS-3 c. Define and differentiate between chemical and physical changes in food.
49.
All of the statements are true of compounds EXCEPT _________________.
Correct Answer
C. A compound is a pure substance
Explanation
FCS-FS-3e. Compare and contrast elements and compounds and explain the difference between ionic and covalent bonds and compounds.
50.
An atom is made of all of the following EXCEPT _______________________.
Correct Answer
D. Reacton
Explanation
FCS-FS-3 a. Describe the parts of an atom.