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 given amount of gas is directly proportional to its temperature in Kelvin, when the pressure remains constant. In other words, as the temperature of a gas increases, its volume also increases, and vice versa. This discovery was an important contribution to the understanding of gas behavior and the development of the gas laws.
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, assuming 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 and increasing the transfer of heat to the food. Therefore, Gay-Lussac's Law is the appropriate law to explain 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
According to Boyle's Law, when the pressure of a gas increases while the temperature remains constant, the volume of the gas decreases. This is because the increased pressure forces the gas particles closer together, resulting in a decrease in volume.
4.
Which of the following figures represents Charles' Law?
Correct Answer
A. Option 1
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 surrounding temperature decreases. As the temperature decreases, the air molecules inside the balloon lose kinetic energy and move slower, causing the air to contract. This contraction leads to a decrease in volume, causing the balloon 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 of gas is best described when a gas tank is filled and more gases can still be added. Compressibility refers to the ability of gas particles to be squeezed closer together, reducing the volume they occupy. In the case of a gas tank, even when it is filled, more gases can still be added by compressing the existing gases, allowing for an increase in the overall gas volume.
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, 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 while the pressure is held constant, the volume of the gas will also increase. This relationship is described by Charles's Law. According to Charles's Law, the volume of a gas is directly proportional to its temperature in Kelvin. In this case, the initial volume of the helium balloon is 15 L at a temperature of 400 K. When the temperature is increased to 600 K, the volume of the balloon will also increase proportionally. Using the formula V1/T1 = V2/T2, we can calculate the new volume. Plugging in the values, we get (15 L)/(400 K) = (V2)/(600 K). Solving for V2, we find that the new volume is 22.5 L. Therefore, the correct answer is 22.5 L.
9.
How will you represent water molecules at 1000C?
Correct Answer
A. Option 1
Explanation
Option 1 is the correct answer because at 1000C, water molecules exist in the form of steam or water vapor. This is because water boils and turns into steam at 1000C. Therefore, representing water molecules at 1000C would involve showing them as individual water vapor molecules or as a cloud of steam.
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, the gas molecules below the piston gain energy and start moving faster. This increased kinetic energy causes the gas molecules to collide more frequently and with greater force against the piston. As a result, the piston is pushed upwards, increasing 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 amount of gas 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 the gas particles also increases. This leads to an increase in the frequency and force of their collisions with the walls of the container. Consequently, the pressure exerted by the gas on the container walls 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 correct answer is "Volume is inversely proportional to the pressure." This can be inferred from the line graph, which shows that as pressure increases, volume decreases. This indicates an inverse relationship between pressure and volume, where an increase in one variable leads to a decrease in the other variable.
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 molecules also increases. This leads to an increase in the average speed and collisions between the gas molecules and the walls of the container. As a result, the gas molecules exert more pressure on the walls, causing the volume of the gas sample to increase. 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, the volume of a gas is directly proportional to its temperature. This means that 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 pressure and volume of a gas are inversely proportional when temperature is held constant. 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, we find that 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 of gas 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 using a balance that can measure up to the nearest hundredths of a gram, you can compare the weight of the balloon before and after it is filled with air. If gases had a significant mass, there would be a measurable increase in weight when the balloon is filled with air. However, if the mass of the balloon remains the same before and after filling it with air, it suggests that gases have negligible mass. This empirical evidence supports 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
When the volume of a gas sample is increased at constant temperature, according to Boyle's Law, the pressure of the gas decreases. This is because there is now a larger volume for the gas particles to occupy, resulting in fewer collisions with the container walls. Therefore, the new pressure will be lower than the initial pressure. The correct answer is 360 torr, as it is the only option that represents a decrease in pressure.
20.
Which of the following is a disaccharide?
Correct Answer
D. Sucrose
Explanation
Sucrose is a disaccharide because it is composed of two monosaccharides, specifically glucose and fructose, joined together by a glycosidic bond. It is commonly found in plants and is a common table sugar used in cooking and baking.
21.
Which of the following pairs of monosaccharide form lactose sugar?
Correct Answer
B. Glucose + Galactose
Explanation
Lactose sugar is a disaccharide composed of two monosaccharides, glucose and galactose, linked together by a glycosidic bond. Therefore, the correct answer is Glucose + 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 have the same molecular formula (C6H12O6) but differ in their structural arrangement. Isomers have the same chemical formula but different structural formulas, resulting in different chemical properties. In the case of fructose and glucose, they have the same number and types of atoms, but the arrangement of atoms is different, giving them distinct properties and functions in biological systems.
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. It is a good source of energy due to its high carbohydrate content, which is important for providing fuel for the body. Potatoes also contain fiber, vitamins, and minerals, making them a nutritious choice for incorporating carbohydrates into a balanced 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 proteins are essential for the growth and repair of tissues in the body. Therefore, the function of amino acids in the body is to make skin, hair, enzymes, and muscles. They are not involved in making fatty acids, vitamins, or producing quick energy.
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 correct answer because it refers to the process of breaking down complex carbohydrates into simple sugars by adding water. In this process, the water molecule is split, with one part attaching to the complex carbohydrate and the other part attaching to the broken bond, resulting in the formation of simple sugars. This process is important for the body to be able to absorb and utilize the energy from 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 linked together. Polysaccharides are large, long-chain molecules that serve as storage and structural compounds in living organisms. Fructose, glucose, and lactose are all monosaccharides or simple sugars, which are smaller carbohydrate molecules.
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 organic compounds that contain both an amino group (-NH2) and a carboxyl group (-COOH) attached to the same carbon atom. They are the building blocks of proteins and play a crucial role in various biological processes. The compound shown in the question likely has an amino group and a carboxyl group attached to a central carbon atom, making it 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 indeed polymers of amino acids, which means they are made up of long chains of amino acid molecules. This is stated in statement I. However, statement II is incorrect because proteins are not insoluble molecules. They can be soluble or insoluble depending on the specific protein and its environment. Statement III is also incorrect because proteins are not derived from aldehydes and ketones with 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 "Substance M is a simple sugar, while substances N and O are not." This statement is correct because it aligns with the information given in the question. The question states that Malou conducted an activity to determine the types of biomolecules present in the 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, such as DNA and RNA, but not in carbohydrates, fats, and oils. Proteins are composed of amino acids, which contain nitrogen, and nucleic acids contain nitrogenous bases. Carbohydrates, fats, and oils primarily consist of carbon, hydrogen, and oxygen. 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 monosaccharides glucose and fructose. In the drawing, there are two hexagons connected by a line, representing the glucose and fructose molecules. Sucrose is a disaccharide composed of one glucose molecule and one fructose molecule, making it the appropriate choice. Galactose, lactose, and maltose are not formed from glucose and fructose, so they are not the correct answers.
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 a chemical change that occurs when the proteins in milk denature and coagulate, forming a solid substance called a precipitate. This process is not influenced by the evolution of gas, change in temperature, or production of heat and light. Therefore, the formation of a precipitate is the most relevant evidence of chemical change in this scenario.
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 a different set of properties compared to the reactants. This is because chemical reactions involve the rearrangement of atoms and the formation of new chemical bonds, resulting in the creation of different molecules with distinct 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 matter cannot be created or destroyed in a chemical reaction, only rearranged. This means that the total mass of the reactants must be equal to the total mass of the products. This principle ensures that a chemical reaction is balanced, with the same number of atoms of each element on both sides of the equation. Therefore, the law of conservation of mass is the correct answer for 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 equation 2KClO3(s) -> 2KCl(s) + 3O2 represents the reaction correctly because it shows that two moles of potassium chlorate react to form two moles of potassium chloride and three moles of oxygen gas. This balanced equation follows the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction.
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 (KClO3), into two simpler substances, potassium chloride (KCl) and oxygen gas (O2), when heated. This type of reaction is known as decomposition, where a single compound breaks down into two or more simpler substances.
37.
Which metal is most reactive?
Correct Answer
B. Rubidium
Explanation
Rubidium is the most reactive metal among the given options. This is because it belongs to the alkali metal group, which is known for its high reactivity. Alkali metals have only one electron in their outermost shell, making it easier for them to lose that electron and form positive ions. Rubidium, with its larger atomic size and lower ionization energy compared to the other options, readily reacts with other elements, especially water and oxygen, resulting in vigorous reactions.
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 carbon, hydrogen, and oxygen atoms on both sides of the equation. By balancing the equation, we ensure that the law of conservation of mass is upheld, meaning that the total number of atoms of each element is the same before and after the reaction.
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. This equation follows the law of conservation of mass, with the same number of atoms of each element on both sides of the equation. It shows that one molecule of methane reacts with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water.
40.
NaCl + AgNO3 --> AgCl +. NaNO3 is an example of what type of chemical reaction?
Correct Answer
C. Double displacement
Explanation
The reaction NaCl + AgNO3 --> AgCl + NaNO3 is an example of a double displacement reaction. In this type of reaction, the cations and anions of two different compounds switch places to form two new compounds. In this case, the sodium cation (Na+) from NaCl combines with the nitrate anion (NO3-) from AgNO3 to form NaNO3, while the silver cation (Ag+) from AgNO3 combines with the chloride anion (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 form. This is because sodium hydroxide reacts with copper sulfate to produce insoluble copper hydroxide, which appears as a solid precipitate. The reaction can be represented by the equation NaOH + CuSO4 → Cu(OH)2 + Na2SO4. Therefore, the most likely outcome of combining these two solutions is the formation of a 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.
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 greater number of collisions between the reactant particles, resulting in 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
The beaker with the fastest rate of reaction will be D. This can be inferred because the question states that all four beakers contain the same amount of iron fillings. Therefore, the rate of reaction will depend on other factors such as temperature, concentration, and presence of catalysts. Since no other information is provided, we can assume that beaker D has the most favorable conditions for a faster reaction compared to the other beakers.
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 reactants is increased, there are more reactant particles available to collide with each other, leading to an increased frequency of successful collisions and a faster reaction rate. On the other hand, when the concentration is decreased, there are fewer reactant particles available, resulting in a decreased frequency of collisions and a slower 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 temperature affects the spoilage of milk because higher temperatures provide a favorable environment for the growth of bacteria and other microorganisms that cause milk to spoil. Heat speeds up the chemical reactions and microbial activity, leading to the souring of milk at a faster rate on a hot summer's day.
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 (I) would increase the rate of the reaction because it provides more energy to the reactant particles, causing them to move faster and collide more frequently, leading to a higher rate of successful collisions. Using smaller marble chips (III) would also increase the rate of the reaction because smaller chips have a larger surface area, providing more area for the acid to react with and increasing the rate of collisions between the acid and the marble chips.
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 marble chips 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 are fewer acid particles available to react with the marble chips. Therefore, both changes II and IV would 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
The correct answer is that the percentage of ammonia increases as both the pressure and temperature increase. This can be inferred from the graph, which shows that as the pressure and temperature increase, the amount of ammonia that can be made from the nitrogen and hydrogen mixture also increases. This suggests that higher pressure and temperature conditions favor the production of ammonia.
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
Both high temperature and pressure can increase the yield of ammonia because the reaction to produce ammonia is exothermic, meaning it releases heat. Increasing the temperature provides the necessary energy for the reaction to occur, while increasing the pressure helps to shift the equilibrium towards the product side, increasing the yield of ammonia.