1.
A(n) _____ is a compound formed when the negative ions from an acid combine with the positive ions to form a base.
Correct Answer
D. Salt
Explanation
When the negative ions from an acid combine with the positive ions to form a base, a compound called a salt is formed. A salt is a chemical compound that is formed by the reaction of an acid with a base. It is composed of positive ions from the base and negative ions from the acid. Therefore, the correct answer is salt.
2.
_____ are solutions containing ions that react with acids or bases to minimize their effects.
Correct Answer
A. Buffers
Explanation
Buffers are solutions containing ions that react with acids or bases to minimize their effects. When an acid is added to a buffer solution, the buffer components react with the acid to neutralize it, preventing a significant change in pH. Similarly, when a base is added, the buffer components react with the base to maintain the pH of the solution. Buffers are important in biological systems as they help maintain the pH within a narrow range, which is necessary for many biochemical reactions to occur properly.
3.
Which of the following bases can be ingested safely?
Correct Answer
A. Aluminum hydroxide
Explanation
Aluminum hydroxide can be ingested safely because it is commonly used as an antacid to relieve symptoms of heartburn, indigestion, and upset stomach. It works by neutralizing excess stomach acid, and it is considered safe for consumption when used as directed. On the other hand, sodium hydroxide, calcium hydroxide, and ammonia are not safe to ingest. Sodium hydroxide is a strong alkali that can cause severe burns and tissue damage if ingested. Calcium hydroxide is also highly alkaline and can cause irritation and damage to the digestive system. Ammonia is a toxic gas that can cause severe respiratory and digestive issues if ingested.
4.
The _____ of a solution is solution is a measure of the concentration of hydronium ions in it.
Correct Answer
C. pH
Explanation
pH is a measure of the concentration of hydronium ions in a solution. It indicates the acidity or alkalinity of a solution on a scale from 0 to 14, with 7 being neutral. A lower pH value indicates a higher concentration of hydronium ions, making the solution more acidic. Conversely, a higher pH value indicates a lower concentration of hydronium ions, making the solution more alkaline. Therefore, pH is the correct answer as it directly relates to the concentration of hydronium ions in a solution.
5.
____ is a chemical reaction between an acid and a base that takes place in a water solution.
Correct Answer
D. Neutralization
Explanation
Neutralization is the correct answer because it is the chemical reaction that occurs when an acid and a base react with each other in a water solution. During neutralization, the hydrogen ions from the acid combine with the hydroxide ions from the base to form water, while the remaining ions combine to form a salt. This reaction results in the neutralization of the acidic and basic properties, leading to the formation of a neutral solution.
6.
In chemical equations describing ionization, what do double arrows pointing in opposite directions indicate?
Correct Answer
B. The ionization reaction is incomplete.
Explanation
The double arrows pointing in opposite directions in a chemical equation indicate that the ionization reaction is incomplete. This means that only a portion of the reactants have undergone ionization and formed products. The reaction may reach a state of equilibrium where both forward and reverse reactions are occurring simultaneously, but not all reactants are converted into products.
7.
Which of the following statements about bases is NOT true?
Correct Answer
C. Bases form when acid reacts and metals.
Explanation
This statement is not true because bases do not form when acid reacts with metals. Bases are substances that can accept protons (H+) or donate pairs of electrons. They can be formed by the reaction of metal oxides or hydroxides with water, or by the reaction of metal carbonates or bicarbonates with acids. However, bases do not form when acids react with metals.
8.
Which two terms refer to the amount of acid or base dissolved in solution?
Correct Answer
C. Dilute and concentrated
Explanation
The terms "dilute" and "concentrated" refer to the amount of acid or base dissolved in a solution. A solution is considered dilute when there is a small amount of acid or base dissolved in a larger amount of solvent. On the other hand, a solution is considered concentrated when there is a large amount of acid or base dissolved in a smaller amount of solvent. Therefore, the correct answer is dilute and concentrated.
9.
Which two groups does a soap molecule contain?
Correct Answer
C. Nonpolar carbon chain and salt of a carboxylic acid
Explanation
A soap molecule contains a nonpolar carbon chain and a salt of a carboxylic acid. The nonpolar carbon chain is hydrophobic and interacts with oily or greasy substances, while the salt of a carboxylic acid is hydrophilic and interacts with water molecules. This dual nature of soap molecules allows them to effectively remove dirt and grease from surfaces by forming micelles, which trap the dirt and grease particles in their hydrophobic cores and are then easily rinsed away with water.
10.
A(n) _____ is an organic compound that changes color in acid.
Correct Answer
D. Indicator
Explanation
An indicator is an organic compound that changes color in acid. Indicators are commonly used in chemistry to determine the pH level of a solution. When an indicator is added to an acidic solution, it will change color, providing a visual indication of the presence of acid. This property makes indicators useful in various applications, such as in titrations or to determine the acidity of a substance.
11.
Which three acids are used in fertilizers?
Correct Answer
D. Nitric, sulfuric, and pHospHoric
Explanation
Nitric, sulfuric, and phosphoric acids are commonly used in fertilizers because they provide essential nutrients for plant growth. Nitric acid is a source of nitrogen, sulfuric acid provides sulfur, and phosphoric acid supplies phosphorus. These nutrients are necessary for plants to develop healthy roots, stems, and leaves, as well as to promote flowering and fruiting. Therefore, the correct answer is nitric, sulfuric, and phosphoric.
12.
A(n) _____ is an organic compound formed by the reaction of an organic acid and an alcohol.
Correct Answer
D. Ester
Explanation
An ester is an organic compound formed by the reaction of an organic acid and an alcohol. This reaction is known as esterification. Esters are commonly used in various industries, such as fragrance and flavor production, as they possess pleasant odors and tastes. Additionally, esters are also used as solvents and plasticizers. They have a wide range of applications due to their unique chemical properties and versatility.
13.
Which of the following composition of cleansers is the best choice if you have hard water?
Correct Answer
C. Long hydrocarbon chain with sulfonic acid group
Explanation
The best choice of cleanser for hard water would be a composition with a long hydrocarbon chain and a sulfonic acid group. Hard water contains high levels of minerals such as calcium and magnesium, which can interfere with the cleaning process. The sulfonic acid group has strong acidic properties that can effectively remove these mineral deposits from surfaces. The long hydrocarbon chain helps to dissolve dirt and grease, making it an ideal choice for cleaning in hard water conditions.
14.
Which of the following substances contains a base?
Correct Answer
C. Fertilizer
Explanation
Fertilizer contains a base because it is typically made up of compounds such as ammonia or potassium hydroxide, which are considered bases. Bases are substances that can accept protons (H+) or donate hydroxide ions (OH-) in a chemical reaction. Aspirin, vinegar, and lemon juice, on the other hand, do not contain bases. Aspirin is an acid, vinegar is a weak acid, and lemon juice is acidic due to the presence of citric acid.
15.
Which of the following has the highest pH?
Correct Answer
C. Ammonia
Explanation
Ammonia has the highest pH among the given options. pH measures the acidity or alkalinity of a solution on a scale of 0-14, with values below 7 indicating acidity and values above 7 indicating alkalinity. Ammonia is a strong base and when dissolved in water, it releases hydroxide ions (OH-) which increases the concentration of hydroxide ions in the solution, resulting in a higher pH. Therefore, ammonia has the highest pH compared to Vitamin C, vinegar, and pure water.
16.
Which of the following statements about acids is NOT true?
Correct Answer
A. Acids form hydroxide ions in solution
17.
A(n) ______ is a substance that produce hydrogen ions in solution.
Correct Answer
D. Acid
Explanation
An acid is a substance that produces hydrogen ions in a solution. When an acid is dissolved in water, it dissociates into hydrogen ions (H+) and anions. These hydrogen ions are responsible for the acidic properties of the solution, such as the sour taste and ability to react with metals. Examples of common acids include hydrochloric acid (HCl), sulfuric acid (H2SO4), and acetic acid (CH3COOH).
18.
What is a disadvantage of adding phosphates to detergents?
Correct Answer
D. pHospHates can cause overgrowth of algae in waterways.
Explanation
Adding phosphates to detergents can lead to an overgrowth of algae in waterways. This is because phosphates act as a nutrient for algae, promoting their growth. When excessive amounts of algae are present in waterways, it can disrupt the ecosystem by depleting oxygen levels and blocking sunlight, which can harm aquatic life. This can lead to a decrease in water quality and negatively impact the balance of the ecosystem. Therefore, the presence of phosphates in detergents can have a detrimental effect on the environment.
19.
Which of the following acids is NOT edible?
Correct Answer
C. Sulfuric
Explanation
Sulfuric acid is not edible because it is a strong acid that is highly corrosive and toxic. It can cause severe burns and damage to the digestive system if ingested. On the other hand, carbonic, lactic, and phosphoric acids are commonly found in food and beverages and are safe for consumption in moderate amounts.
20.
_____ are organic salts.
Correct Answer
C. Soaps
Explanation
Soaps are organic salts because they are formed by the reaction of a fatty acid with an alkali, such as sodium hydroxide or potassium hydroxide. This reaction, known as saponification, results in the formation of a salt called a soap. Soaps have a polar end (hydrophilic) and a nonpolar end (hydrophobic), which allows them to dissolve in both water and oil. This property makes them effective for cleaning and removing dirt and grease from surfaces.
21.
Match the following characteristics to either an acid or a base:
-
type of ions produced in a solution: H+
-
charge of ion: positive
-
taste: sour
-
common example: HCl
-
pH: <7
-
common use: fertilizers
Correct Answer
A. Acid
Explanation
The given characteristics, such as the type of ions produced in a solution (H+), the taste (sour), the common example (HCl), and the pH (
22.
Match the following characteristics to either and acid or a base:
-
type of ions produced in a solution: OH-
-
charge of ion: negative
-
taste: bitter
-
common example: ammonia
-
pH: >7
-
common use: food preparation
Correct Answer
B. Base
Explanation
The characteristics provided in the question are all associated with bases. Bases produce OH- ions in a solution, have a negative charge, taste bitter, have a pH greater than 7, and are commonly used in food preparation. The common example given, ammonia, is also a base. Therefore, the correct answer is base.