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 when pressure is held constant. Charles conducted experiments in the late 18th century and discovered that as the temperature of a gas increases, its volume also increases, and vice versa. His work was instrumental in the development of the gas laws and our understanding of the behavior of gases.
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. This law states that the pressure of a gas is directly proportional to its temperature, provided that the volume and amount of gas remain constant. In a pressure cooker, as the temperature increases, the pressure inside the cooker also increases. This increase in pressure allows the food to cook faster by raising the boiling point of water, resulting in faster cooking times.
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 volume of the gas decreases. This can be explained by Boyle's Law, which states that the volume of a gas is inversely proportional to its pressure at constant temperature. As the pressure increases, the gas particles are pushed closer together, resulting in a decrease in volume.
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. Option 1 is a graph that shows an increase in volume as temperature increases, which is in line with 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 filled with warm air is placed in a refrigerator, the temperature inside the refrigerator is much colder than the temperature of the air inside the balloon. As a result, the air molecules inside the balloon lose heat 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 ability of gas molecules to be squeezed closer together, reducing the volume they occupy. When a gas tank is filled and more gases can still be added, it indicates that the gas molecules are not tightly packed and there is room for further compression.
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 held constant, the volume of the gas is directly proportional to its temperature. In this case, the temperature of the helium is increased from 400 K to 600 K. Since the volume is directly proportional to the temperature, the volume of the helium balloon will also increase. Therefore, the volume of the helium balloon will be 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 the temperature increases, the gas molecules gain more kinetic energy and move faster. This increased movement causes the gas molecules to collide more frequently and with greater force against the piston. The cumulative effect of these collisions leads to an increase in pressure exerted by the gas on the piston, causing it to move upwards. As the piston moves up, the volume of the gas increases, resulting in the volume of the gas increasing.
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 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 of a gas increases, the kinetic energy of the gas molecules also increases. This causes the gas molecules to move faster and collide with the walls of the container more frequently and with greater force. The increased frequency and force of these collisions result in an increase in the gas pressure. 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. This indicates an inverse relationship between pressure and volume. As pressure increases, the particles in the gas are compressed, resulting in a decrease in volume. Therefore, the correct answer is that volume is inversely proportional to the 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 the gas particles also increases. This causes the gas particles to move faster and collide with each other and the container walls more frequently and with greater force. These collisions result in an increase in the volume of the gas sample. Therefore, the correct answer is that the volume of the gas increases.
15.
What is the volume of the gas sample when the temperature is 150 K?
Correct Answer
C. 3 L
Explanation
At constant pressure, according to Charles's Law, the volume of a gas is directly proportional to its temperature. Therefore, as the temperature increases, the volume of the gas sample also increases. In this case, when the temperature is 150 K, the volume of the gas sample is 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 will decrease. This is because the pressure and volume of a gas are inversely proportional. In this case, the volume is increased from 100 mL to 150 mL, which means the pressure will decrease. The new pressure can be calculated using the formula P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume. Plugging in the values, we get (3.0 atm)(100 mL) = (P2)(150 mL). Solving for P2 gives us a new pressure of 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 of gas present. Therefore, the container with 4 moles of gas will have the highest pressure compared to the containers with 1, 2, and 3 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. If gases had significant mass, there would be a noticeable increase in weight when the balloon is filled with air. However, if there is no significant change in weight, it suggests that gases have negligible mass. This can be supported by the equation of mass, where the mass of an object is equal to the weight divided by the acceleration due to gravity. Since the weight of the balloon does not significantly change, it implies that the mass of the gas inside is negligible.
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
When the volume of a gas sample is increased while keeping the temperature constant, the pressure of the gas decreases. This relationship is described by Boyle's Law. According to Boyle's Law, the product of pressure and volume is constant at a constant temperature. In this case, the initial pressure is 720 torr and the initial volume is 125 mL. When the volume is increased to 250 mL, the new pressure can be calculated using the formula P1V1 = P2V2. Plugging in the values, we get (720 torr)(125 mL) = (P2)(250 mL). Solving for P2 gives us a new pressure of 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. Disaccharides are carbohydrates that consist of two sugar molecules linked together. Fructose, galactose, and glucose are all monosaccharides, which means they are single sugar molecules and not disaccharides.
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 they have the same molecular formula (C6H12O6) but differ in their structural arrangement. Isomers have the same number and type of atoms, but their arrangement is different, resulting in distinct chemical properties. In the case of fructose and glucose, they are both monosaccharides and hexoses, but their structures differ in the placement of the hydroxyl groups around the carbon atoms.
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 an essential macronutrient that provides energy to the body. Potatoes are also a good source of fiber, vitamins, and minerals. While fruits like apple and vegetables also contain carbohydrates, potato is specifically known for its high carbohydrate content. Milk, on the other hand, is not a significant source of carbohydrates as it primarily contains proteins and fats.
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, which are essential for the growth and repair of body tissues. They are used to make skin, hair, enzymes, and muscles. Amino acids are not involved in the production of fatty acids or vitamins. While they can be used as a source of energy, their primary function is to support the structure and function of various body tissues.
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 that describes the addition of water to a complex carbohydrate, resulting in the production of simple sugars. This process breaks down the complex carbohydrate into its individual components through the use of water molecules. Condensation and dehydration are opposite processes, involving the removal of water to form larger molecules. Photosynthesis, on the other hand, is the process by which plants convert sunlight into energy.
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 support to plants. Fructose, glucose, and lactose are all monosaccharides or disaccharides, 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 an example of an amino acid. Amino acids are the building blocks of proteins and contain both an amino group (-NH2) and a carboxyl group (-COOH) attached to a central carbon atom. The compound in question appears to have these functional groups, indicating that it is 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 that statement I is true. However, statement II is false because proteins are not insoluble molecules composed of carbon, hydrogen, and oxygen. Statement III is also false because proteins are not molecules from aldehydes and ketones containing numerous hydroxyl groups. Therefore, the correct answer is I and III only.
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 that Substance M is a simple sugar, while substances N and O are not. This conclusion can be drawn by analyzing the information provided in the question. The question states that Malou conducted an activity to determine the types of biomolecules present in the three unknown substances. Based on the given options, it can be inferred that Substance M is a simple sugar because it is the only substance mentioned as such. Additionally, it is stated that substances N and O are not simple sugars, which eliminates the other options. Therefore, the correct statement is 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, which are essential components of living organisms. Carbohydrates, fats, and oils do not contain nitrogen. Therefore, nitrogen is the element that is found in proteins and nucleic acids but not in carbohydrates, fats, and oils.
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 the combination of glucose and fructose. The drawing shows two monosaccharides, which are glucose and fructose, and when they combine through a condensation reaction, they form sucrose. Galactose, lactose, and maltose are not formed from the combination of glucose and fructose, so they are not the correct answer.
32.
Which of the following evidence of chemical change explains the curdling of milk?
Correct Answer
B. Formation of precipitate
Explanation
The curdling of milk is an example of a chemical change because it involves the formation of a precipitate. A precipitate is a solid substance that forms when two liquids react chemically. In the case of milk curdling, the reaction between the proteins in milk and an acid causes the proteins to denature and form solid clumps, resulting in the curdled appearance. This formation of a precipitate is a clear indication that a chemical change has occurred.
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
During a chemical reaction, new substances are formed with different properties than the reactants. This is because the atoms in the reactants rearrange themselves to form new chemical bonds, resulting in the formation of new substances with different chemical and physical properties. This is a fundamental principle of chemical reactions and is often observed in various chemical processes.
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 in a chemical reaction, matter cannot be created or destroyed, only rearranged. This means that the total mass of the reactants must be equal to the total mass of the products. This law ensures that a chemical reaction is balanced, meaning that the number of atoms of each element is the same on both sides of the equation.
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 equation 2KClO3(s) → 2KCl(s) + 3O2 represents the given reaction because it shows that two moles of potassium chlorate (KClO3) decompose to form two moles of potassium chloride (KCl) and three moles of oxygen gas (O2). 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.
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 simpler substances, potassium chloride and oxygen gas. This type of reaction is known as decomposition, where a compound is broken down into its constituent elements or simpler compounds.
37.
Which metal is most reactive?
Correct Answer
B. Rubidium
Explanation
Rubidium is the most reactive metal among the options given. This is because it is located in Group 1 of the periodic table, also known as the alkali metals. Alkali metals are highly reactive due to their low ionization energies and the ease with which they lose their outermost electron to form positive ions. Rubidium, being an alkali metal, exhibits similar characteristics and reacts vigorously with water and other substances. Copper, strontium, and vanadium, on the other hand, are not as reactive as rubidium because they belong to different groups in the periodic table.
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, a lighter fluid, is 2C4H10 + 13O2 -> 8CO2 + 10H2O. This equation shows that two molecules of butane (C4H10) react with 13 molecules of oxygen (O2) to produce eight molecules of carbon dioxide (CO2) and 10 molecules of water (H2O). This equation is balanced because the number of atoms of each element is the same on both sides of the equation.
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
40.
NaCl + AgNO3 --> AgCl +. NaNO3 is an example of what type of chemical reaction?
Correct Answer
C. Double displacement
Explanation
The given chemical equation shows a reaction between NaCl and AgNO3, which results in the formation of AgCl and NaNO3. This type of reaction is known as a double displacement reaction. In a double displacement reaction, the positive ions of two compounds exchange places, forming two new compounds. In this case, the sodium ion (Na+) from NaCl combines with the nitrate ion (NO3-) from AgNO3 to form NaNO3, while the silver ion (Ag+) from AgNO3 combines with the chloride ion (Cl-) from NaCl to form AgCl.
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 most likely 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) as a precipitate. This can be represented by the equation NaOH + CuSO4 → Cu(OH)2 + Na2SO4. The formation of a precipitate indicates a chemical reaction has taken place between the two substances.
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 when sulfur trioxide (SO3) reacts with water (H2O), it forms sulfuric acid (H2SO4). The equation is balanced because the number of atoms of each element is equal on both sides of the equation.
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. When iron filings are used in a reaction with hydrochloric acid, the increased surface area allows for more contact between the iron and the acid. This increased contact leads to a higher rate of reaction because more iron particles are exposed to the acid, resulting in more collisions between the reactants and therefore a faster 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 size of the iron fillings in each beaker is not specified. However, it can be assumed that the iron fillings in beaker D are smaller in size compared to the other beakers. Smaller iron fillings have a larger surface area, which allows for more frequent collisions with the reactant molecules. This increased surface area leads to a faster 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 because a higher concentration of reactants means that there are more particles available to collide and react with each other. This increases the frequency of successful collisions and therefore increases the reaction rate. Conversely, a lower concentration of reactants decreases the frequency of collisions and slows down the reaction rate.
46.
Milk becomes sour more quickly on a hot summer’s day. Which factor affects the spoilage of milk?
Correct Answer
D. Temperature
Explanation
Temperature affects the spoilage of milk because higher temperatures provide an ideal environment for the growth of bacteria. Bacteria multiply rapidly in warm temperatures, causing milk to spoil 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 and using smaller marble chips would increase the rate of the reaction between dilute hydrochloric acid and marble chips. When the temperature is increased, the kinetic energy of the particles increases, leading to more frequent and energetic collisions between the acid and the marble chips. This increases the rate of reaction. Using smaller marble chips increases the surface area of the reactant, providing more sites for the acid to react with. This also increases the rate of 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 pieces of marble have a smaller surface area, which reduces the number of collisions 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. Therefore, changes II and IV would both decrease the rate of the reaction.
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 mixture of nitrogen and hydrogen also increases.
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 the temperature and pressure can increase the yield of ammonia because it helps to shift the equilibrium towards the formation of more ammonia. According to Le Chatelier's principle, increasing the temperature favors the endothermic reaction that produces ammonia, while increasing the pressure favors the reaction that reduces the volume of gas molecules, which in this case is the formation of ammonia. Therefore, both high temperature and pressure conditions can increase the yield of ammonia.