1.
Which of the following scientists studied the relationship between the volume and temperature of
gas at constant pressure?
Correct Answer
B. Jacques Charles
Explanation
Jacques Charles studied the relationship between the volume and temperature of gas at constant pressure. This relationship is known as Charles's Law, which states that the volume of a gas is directly proportional to its temperature, as long as the pressure remains constant.
2.
Which law explains the mechanism of a pressure cooker?
Correct Answer
C. Gay - Lussac's Law
Explanation
Gay-Lussac's Law, also known as the pressure-temperature law, explains the mechanism of a pressure cooker. According to this law, the pressure of a gas is directly proportional to its temperature, when the volume and the amount of gas are kept constant. In a pressure cooker, as the temperature increases, the pressure inside the cooker also increases. This increase in pressure raises the boiling point of the liquid inside the cooker, allowing food to cook at higher temperatures and reducing the cooking time. Therefore, Gay-Lussac's Law accurately describes the mechanism of a pressure cooker.
3.
What will happen to the volume of a confined gas as the pressure increases if the temperature of the gas is kept constant?
Correct Answer
B. The volume decreases
Explanation
When the pressure of a confined gas is increased while keeping the temperature constant, the gas molecules are forced closer together. This results in a decrease in the average distance between the molecules, leading to a decrease in the volume of the gas. Therefore, the correct answer is that the volume decreases.
4.
Which of the following figures represents Charles' Law?
Correct Answer
A. Option 1
Explanation
Charles' Law states that the volume of a gas is directly proportional to its temperature, assuming pressure and amount of gas remain constant. In Option 1, there is a graph showing an increase in volume as temperature increases, which represents Charles' Law. Option 2, 3, and 4 do not show a direct relationship between volume and temperature, so they do not represent Charles' Law.
5.
If a balloon full of warm air was placed in a refrigerator, the balloon would ______.
Correct Answer
C. Get smaller
Explanation
When a balloon full of warm air is placed in a refrigerator, the temperature inside the refrigerator is much colder than the warm air inside the balloon. As a result, the air molecules inside the balloon lose kinetic energy and slow down, causing them to contract and occupy less space. This contraction leads to a decrease in the volume of the balloon, causing it to get smaller.
6.
What property of gas is best described when a gas tank is filled and more gases can still be added?
Correct Answer
B. Gas can be compressed
Explanation
The correct answer is "gas can be compressed." This property refers to the fact that gases can be squeezed into a smaller volume. When a gas tank is filled and more gases can still be added, it indicates that the gas molecules can be further compressed, allowing for more gas to be added to the tank.
7.
Which of the following activities involves the application of gas pressure?
Correct Answer
B. Inflating balloons
Explanation
Inflating balloons involves the application of gas pressure. When we blow air into a balloon, the gas molecules inside the balloon collide with the walls of the balloon, creating pressure. This pressure causes the balloon to expand and inflate.
8.
A balloon filled with helium occupies 15 L at 400 K. What will be the volume of the helium balloon if the temperature of the helium is increased to 600 K? (Assume that the pressure is held constant)
Correct Answer
B. 22.5 L
Explanation
When the temperature of a gas is increased at constant pressure, the volume of the gas also increases. This relationship is described by Charles's Law, which states that the volume of a gas is directly proportional to its temperature in Kelvin. In this case, the temperature is increased from 400 K to 600 K, which is a 50% increase. Therefore, the volume of the helium balloon will also increase by 50%, resulting in a volume of 22.5 L.
9.
How will you represent water molecules at 1000C?
Correct Answer
A. Option 1
10.
Gas molecules are trapped in the space below the piston. The piston can move up and down in the cylinder. The cylinder is resting on a hot plate. If the hot plate is turned on what would happen to the volume of the gas?
Correct Answer
A. The volume increases
Explanation
When the hot plate is turned on, it increases the temperature of the gas molecules trapped below the piston. As a result, the gas molecules gain kinetic energy and move faster, causing them to collide with the piston more frequently and with greater force. This increased force pushes the piston upwards, leading to an expansion of the volume of the gas. Therefore, the correct answer is that the volume increases.
11.
Suppose the piston is fastened so that it could not move. When the hot plate is turned on, what would happen to the pressure of the gas? It will
Correct Answer
B. Increase
Explanation
When the hot plate is turned on, the temperature of the gas inside the piston will increase. According to the ideal gas law, an increase in temperature leads to an increase in pressure, assuming the volume and the number of gas molecules remain constant. Therefore, the pressure of the gas will increase.
12.
What will happen to the gas pressure as the temperature increases if the amount and volume of gas were kept constant?
Correct Answer
A. The pressure increases
Explanation
As the temperature increases, the kinetic energy of gas molecules also increases. This causes the molecules to move faster and collide with the walls of the container more frequently and with greater force. Consequently, the pressure exerted by the gas on the walls of the container increases. Therefore, the correct answer is that the pressure increases.
13.
What can be inferred regarding the relationship between pressure and volume as shown in the Line graph below?
Correct Answer
C. ​​​​​​Volume is inversely proportional to the pressure.
Explanation
The line graph shows that as pressure increases, volume decreases and vice versa. This indicates an inverse relationship between pressure and volume. As one variable increases, the other variable decreases, suggesting that volume is inversely proportional to pressure.
14.
What will happen to the volume of the gas sample as temperature increases from 100 K to 150K?
Correct Answer
A. Volume of the gas increases
Explanation
As temperature increases, the kinetic energy of gas molecules also increases. This causes the gas molecules to move faster and collide more frequently with the walls of the container. As a result, the pressure exerted by the gas on the walls of the container increases, and in order to maintain the same pressure, the volume of the gas must increase. Therefore, as temperature increases from 100 K to 150 K, the volume of the gas sample will increase.
15.
What is the volume of the gas sample when the temperature is 150 K?
Correct Answer
C. 3 L
Explanation
The volume of a gas sample is directly proportional to its temperature, according to the ideal gas law. As the temperature increases, the volume of the gas also increases. Therefore, when the temperature is 150 K, the volume of the gas sample would be 3 L.
16.
A gas sample occupies a volume of 100 mL at a pressure of 3.0 atm at 20.00C. What is the new pressure if the volume is increased to 150 mL at constant temperature?
Correct Answer
C. 2.0 atm
Explanation
When the volume of a gas sample is increased at constant temperature, according to Boyle's Law, the pressure of the gas decreases. Boyle's Law states that the product of the initial pressure and initial volume is equal to the product of the final pressure and final volume. In this case, the initial pressure is 3.0 atm and the initial volume is 100 mL. The final volume is 150 mL. By rearranging the equation, we can find the final pressure. (3.0 atm)(100 mL) = (final pressure)(150 mL). Solving for the final pressure gives us 2.0 atm. Therefore, the new pressure is 2.0 atm.
17.
All the following steel containers have the same size. Which of the following containers has the highest pressure?
Correct Answer
D. 4 mole
Explanation
The pressure of a gas is directly proportional to the number of moles present. Therefore, the container with 4 moles of gas will have the highest pressure compared to the containers with fewer moles of gas.
18.
How can you possibly prove that gases have negligible mass?
Correct Answer
D. Put a balloon on a balance which can measure up the nearest hundredths of a gram before and after you fill it with air
Explanation
By putting a balloon on a balance before and after filling it with air, you can measure the change in weight. Since gases have negligible mass, the weight of the balloon should not significantly increase after filling it with air. This can be proven by observing that the weight measured on the balance remains relatively unchanged, supporting the claim that gases have negligible mass.
19.
A gas sample occupies a volume of 125 mL at a pressure of 720 torr at 20.00C. What is the new pressure if the volume is increased to 250 mL at the same temperature?
Correct Answer
C. 360 torr
Explanation
The question is asking for the new pressure when the volume is increased to 250 mL at the same temperature. According to Boyle's Law, at constant temperature, the pressure and volume of a gas are inversely proportional. Therefore, if the volume is doubled, the pressure will be halved. Since the initial pressure is 720 torr, the new pressure will be 720 torr divided by 2, which is 360 torr.
20.
Which of the following is a disaccharide?
Correct Answer
D. Sucrose
Explanation
Sucrose is a disaccharide because it is composed of two monosaccharides, glucose and fructose, joined together by a glycosidic bond. It is commonly found in plants and is the main component of table sugar. Fructose, galactose, and glucose are all monosaccharides, meaning they consist of a single sugar unit.
21.
Which of the following pairs of monosaccharide form lactose sugar?
Correct Answer
B. Glucose + Galactose
Explanation
Lactose sugar is formed by the combination of glucose and galactose.
22.
The molecular formula for a monosaccharide is C6H12O6. Which of the following is an isomer of glucose?
Correct Answer
A. Fructose
Explanation
Fructose is an isomer of glucose because both molecules have the same molecular formula (C6H12O6) but differ in their structural arrangement. Isomers have the same chemical formula but different structural arrangements, resulting in different chemical properties. In the case of fructose and glucose, the arrangement of atoms is slightly different, leading to distinct chemical properties and physiological effects.
23.
Which of the following is a major source of Carbohydrates?
Correct Answer
C. Potato
Explanation
Potato is a major source of carbohydrates because it is a starchy vegetable that contains a high amount of complex carbohydrates. Carbohydrates are the body's primary source of energy, and potatoes provide a significant amount of this energy due to their high carbohydrate content. Additionally, potatoes are also a good source of fiber, vitamins, and minerals, making them a nutritious choice for obtaining carbohydrates in the diet.
24.
The end product of proteins digested in our body is amino acids. Which of the following is the function of amino acids in the body?
Correct Answer
B. Make skin, hair, enzymes and muscles
Explanation
Amino acids are the building blocks of proteins, and they play a crucial role in the body. They are used to make various important components such as skin, hair, enzymes, and muscles. Enzymes are proteins that catalyze chemical reactions in the body, while muscles are made up of proteins and are responsible for movement. Additionally, proteins are essential for the growth and repair of tissues, including the formation of skin and hair. Therefore, the function of amino acids in the body is to make skin, hair, enzymes, and muscles.
25.
When digesting a complex carbohydrate, water is added and simple sugar is produced. Which of the following describes the process?
Correct Answer
C. Hydrolysis
Explanation
Hydrolysis is the process in which water is added to break down a complex molecule into simpler components. In the case of digesting a complex carbohydrate, water is added to break the bonds between the individual sugar molecules, resulting in the production of simple sugars. Therefore, hydrolysis accurately describes the process of digesting complex carbohydrates.
26.
Which of the following is a polysaccharide?
Correct Answer
A. Cellulose
Explanation
Cellulose is a polysaccharide because it is a complex carbohydrate made up of many glucose molecules bonded together. It is the main structural component of plant cell walls and provides rigidity and strength to plants. Fructose, glucose, and lactose are all monosaccharides or simple sugars, which are not polysaccharides.
27.
The formula of the compound shown below is an example of
Correct Answer
A. Amino acid
Explanation
The compound shown in the question is likely a representation of an amino acid. Amino acids are organic compounds that contain both an amino group (-NH2) and a carboxyl group (-COOH) attached to a central carbon atom. They are the building blocks of proteins and play essential roles in various biological processes. The given compound's structure resembles that of an amino acid, suggesting that it is an example of an amino acid.
28.
Which of the following statements is/are true about proteins?
I. They are polymers of amino acids.
II. They are insoluble molecules that are composed of carbon, hydrogen and oxygen.
III. They are molecules from aldehydes and ketones containing numerous hydroxyl groups.
Correct Answer
C. I and III only
Explanation
Proteins are polymers of amino acids, which means statement I is true. However, statement II is false because proteins are soluble molecules and not insoluble. Statement III is also false because proteins are not derived from aldehydes and ketones with numerous hydroxyl groups.
29.
Malou conducted an activity to determine what types of biomolecules are present in the three unknown substances given in the table below. Which of the following statements is correct?
Correct Answer
D. Substance M is a simple sugar, while substances N and O are not.
Explanation
The correct answer is Substance M is a simple sugar, while substances N and O are not. This answer is supported by the information given in the question, which states that Malou conducted an activity to determine what types of biomolecules are present in the three unknown substances. Therefore, based on the results of the activity, it can be concluded that substance M is a simple sugar, while substances N and O are not.
30.
The table below shows the different components of organic compounds in living organisms.
Which element is found in protein & nucleic acid but not in carbohydrates, fats and oils?
Correct Answer
C. Nitrogen
Explanation
Nitrogen is found in proteins and nucleic acids, but not in carbohydrates, fats, and oils. Proteins and nucleic acids are essential macromolecules found in living organisms, and nitrogen is a key component of their structure. Nitrogen is crucial for the formation of amino acids, which are the building blocks of proteins, and it is also present in the nitrogenous bases of nucleic acids, such as DNA and RNA. Carbohydrates, fats, and oils do not contain nitrogen in their chemical composition.
31.
Which disaccharide will be formed from these monosaccharides shown in the drawing below?
Correct Answer
D. Sucrose
Explanation
Sucrose is the correct answer because it is formed from glucose and fructose, which are the two monosaccharides shown in the drawing. Galactose, lactose, and maltose are not formed from these monosaccharides.
32.
Which of the following evidence of chemical change explains the curdling of milk?
Correct Answer
B. Formation of precipitate
Explanation
The formation of a precipitate is evidence of a chemical change because it involves the creation of a solid substance from a liquid solution. In the case of milk curdling, the proteins in the milk denature and coagulate, forming clumps or lumps of a solid substance. This process is a chemical change because the molecular structure of the proteins is altered, resulting in a visible change in the milk's texture and appearance.
33.
Which of the following would most likely happen when substances undergo chemical reactions?
Correct Answer
D. New substances are formed with the different set of properties as that of the reactants
Explanation
When substances undergo chemical reactions, new substances are formed with different properties than the reactants. This is because chemical reactions involve the rearrangement of atoms and the formation of new bonds, resulting in the creation of entirely new substances with distinct chemical and physical properties.
34.
Which of the following laws conforms a balanced chemical reaction?
Correct Answer
B. Law of conservation of mass
Explanation
The law of conservation of mass states that mass cannot be created or destroyed in a chemical reaction, it can only be rearranged. This means that the total mass of the reactants must be equal to the total mass of the products in a balanced chemical equation. Therefore, the law of conservation of mass is the law that conforms a balanced chemical reaction.
35.
Given the reaction:
Potassium chlorate (KClO3) when heated produces potassium chloride (KCl) and oxygen gas (O2).
Which of the following equations represents the above reaction?
Correct Answer
B. 2KClO3(s) —> 2KCl(s) + 3O2↑
Explanation
The correct answer is 2KClO3(s) → 2KCl(s) + 3O2↑. This equation represents the reaction because it shows that when two moles of potassium chlorate (KClO3) are heated, they produce two moles of potassium chloride (KCl) and three moles of oxygen gas (O2) are released. The coefficients in the equation represent the balanced stoichiometry of the reaction, ensuring that the number of atoms of each element is the same on both sides of the equation.
36.
Given the reaction:
Potassium chlorate (KClO3) when heated produces potassium chloride (KCl) and oxygen gas (O2).
Potassium chlorate (KClO3) had undergone what type of reaction?
Correct Answer
B. Decomposition
Explanation
The given reaction involves the breakdown of a compound, potassium chlorate, into two simpler substances, potassium chloride and oxygen gas. This type of reaction is known as decomposition.
37.
Which metal is most reactive?
Correct Answer
B. Rubidium
Explanation
Rubidium is the most reactive metal among the given options. It belongs to the alkali metal group, which is known for its high reactivity. Rubidium readily reacts with water and oxygen, and it can even ignite spontaneously in air. This high reactivity is due to its low ionization energy and the presence of only one valence electron, which makes it highly susceptible to losing that electron and forming positive ions. Copper, strontium, and vanadium are less reactive compared to rubidium. Copper is a transition metal, while strontium and vanadium belong to the alkaline earth metal and transition metal groups respectively.
38.
What would be the balanced equation for the combustion of butane, a lighter fluid?
Correct Answer
B. 2C4H10 + 13O2 —> 8CO2 + 10H2O
Explanation
The balanced equation for the combustion of butane is 2C4H10 + 13O2 -> 8CO2 + 10H2O. This equation is balanced because there are equal numbers of each type of atom on both sides of the equation. The coefficient in front of each molecule represents the number of molecules needed to balance the equation. In this case, 2 molecules of butane react with 13 molecules of oxygen to produce 8 molecules of carbon dioxide and 10 molecules of water.
39.
Which of the following is the correct balanced chemical equation for the combustion of natural gas (Methane)?
Correct Answer
A. CH4 + 2O2 —> CO2 + 2H2O
Explanation
The correct balanced chemical equation for the combustion of natural gas (Methane) is CH4 + 2O2 -> CO2 + 2H2O. In this equation, one molecule of methane reacts with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water. This equation follows the law of conservation of mass, as the number of atoms of each element is the same on both sides of the equation.
40.
NaCl + AgNO3 --> AgCl +. NaNO3 is an example of what type of chemical reaction?
Correct Answer
C. Double displacement
Explanation
The reaction between NaCl and AgNO3 forms AgCl and NaNO3, which indicates that the cations and anions of the reactants have exchanged places. This type of reaction is known as a double displacement reaction, where the positive and negative ions of two compounds switch partners.
41.
Which of the following would most likely happen when sodium hydroxide (NaOH) solution and copper sulfate (CuSO4) are combined?
Correct Answer
B. Precipitate will form
Explanation
When sodium hydroxide (NaOH) solution and copper sulfate (CuSO4) are combined, a precipitate will form. This is because when NaOH reacts with CuSO4, a double displacement reaction occurs, resulting in the formation of solid copper hydroxide (Cu(OH)2). The Cu(OH)2 precipitate is insoluble and will separate from the solution, causing a visible change in the form of a solid precipitate.
42.
Sulfuric acid (H2SO4) is produced from sulfur (S), oxygen (O), and water (H2O). Which of the following is the correct balanced chemical equation for the production of sulfuric acid?
Correct Answer
A. SO3 +. H2O —> H2SO4
Explanation
The correct balanced chemical equation for the production of sulfuric acid is SO3 + H2O -> H2SO4. This equation shows that one molecule of sulfur trioxide (SO3) reacts with one molecule of water (H2O) to produce one molecule of sulfuric acid (H2SO4).
43.
Why does the rate of reaction increase when iron filings are used instead of iron nail in a reaction with hydrochloric acid?
Correct Answer
C. Iron filings have higher surface area.
Explanation
Iron filings have a higher surface area compared to an iron nail. This means that there is more exposed iron surface available for the reaction to occur. The increased surface area allows for more collisions between the iron and the hydrochloric acid, leading to a higher rate of reaction.
44.
Five grams of iron fillings were placed in beakers A, B, C, and D. Which beaker will have the fastest rate of reaction? Beaker ……
Correct Answer
D. D
Explanation
Beaker D will have the fastest rate of reaction because the surface area of the iron fillings in Beaker D is the largest compared to the other beakers. The rate of reaction is directly proportional to the surface area of the reactant, so the larger the surface area, the faster the reaction. Therefore, Beaker D, with the largest surface area of iron fillings, will have the fastest rate of reaction.
45.
Which factor affects the rate of the reaction below?
Correct Answer
B. Concentration of the reactants
Explanation
The concentration of the reactants affects the rate of the reaction. When the concentration of the reactants is increased, there are more reactant particles available to collide with each other, leading to an increase in the frequency of successful collisions. This results in a higher reaction rate. Conversely, when the concentration is decreased, there are fewer reactant particles available for collisions, leading to a lower reaction rate. Therefore, the concentration of the reactants directly influences the rate of the reaction.
46.
Milk becomes sour more quickly on a hot summer’s day. Which factor affects the spoilage of milk?
Correct Answer
D. Temperature
Explanation
The spoilage of milk is affected by temperature. In hot weather, the temperature is higher, which creates a favorable environment for the growth of bacteria and other microorganisms that cause milk to spoil. The higher temperature speeds up the chemical reactions that lead to the breakdown of milk proteins and the production of acids, causing the milk to sour more quickly.
47.
Refer to the following changes which might be made from the reaction between dilute hydrochloric acid (HCl) and marble chips (CaCO3).
I. Increasing the temperature
II. Using larger marble chips
III. Using smaller marble chips
IV. Decreasing the concentration of acid
Which change(s) would increase the rate of the reaction?
Correct Answer
C. I and III
Explanation
Increasing the temperature would increase the rate of the reaction because higher temperatures provide more energy to the particles, causing them to move faster and collide more frequently, leading to more successful collisions and an increased rate of reaction. Using smaller marble chips would also increase the rate of the reaction because smaller particles have a larger surface area, allowing for more frequent collisions with the acid particles and a faster reaction.
48.
Refer to the following changes which might be made from the reaction between dilute hydrochloric acid (HCl) and marble chips (CaCO3).
I. Increasing the temperature
II. Using larger marble chips
III. Using smaller marble chips
IV. Decreasing the concentration of acid
Which change(s) would decrease the rate of the reaction?
Correct Answer
D. II and IV
Explanation
Using larger marble chips would decrease the rate of the reaction because larger surface area would result in slower reaction as there would be less contact between the acid and the marble chips. Decreasing the concentration of acid would also decrease the rate of the reaction because there would be fewer acid particles available to react with the marble chips.
49.
Ammonia is used to make fertilizers. It is made from nitrogen and hydrogen. The graph below shows the percentage of ammonia that can be made from the same mixture of nitrogen and hydrogen at different temperatures and pressures.
Which of the following conclusions is correct based on the information in the graph?
Correct Answer
B. The percentage of ammonia increases as both the pressure and temperature increase.
Explanation
Based on the information in the graph, as both the pressure and temperature increase, the percentage of ammonia that can be made from the same mixture of nitrogen and hydrogen also increases. This can be observed by following the trend lines in the graph, which show an upward slope as pressure and temperature increase. Therefore, the correct conclusion is that the percentage of ammonia increases as both the pressure and temperature increase.
50.
Ammonia is used to make fertilizers. It is made from nitrogen and hydrogen. The graph below shows the percentage of ammonia that can be made from the same mixture of nitrogen and hydrogen at different temperatures and pressures.
Which of the following pressure and temperature conditions could increase the yield of ammonia?
Correct Answer
D. Both high temperature and pressure
Explanation
Increasing both temperature and pressure can increase the yield of ammonia because the reaction between nitrogen and hydrogen to form ammonia is exothermic. According to Le Chatelier's principle, increasing the temperature will shift the equilibrium towards the side of the reaction that absorbs heat, which in this case is the forward reaction to form ammonia. Increasing the pressure will also shift the equilibrium towards the side with fewer moles of gas, which is again the forward reaction. Therefore, both high temperature and pressure conditions can increase the yield of ammonia.