CHEM103/ CHEM 103 Module 6 – General Chemistry I with Lab | Portage Learning | Latest Exam Questions & Answers | Verified Study Material | Grade A

CHEM103/ CHEM 103 Module 6 – General Chemistry I with Lab | Portage Learning | 2026 2027 Latest Exam Questions & Answers | Verified Study Material | Grade A 2026 / 2027 Academic Year Q: What is an amorphous solid? Answer A solid where the particles are arranged randomly and do not have any order. (Ex. Plastic and Rubber) Q: What is a colligative property? Answer properties that depend on the concentration of solute particles but not on their identity. Includes the boiling point, freezing point, and vapour pressure. Q: What is a colloid? Answer Appears to be a homo-geneous mixture but is actually composed of separate particles that is too small to be able to see. Q: What is condensation? Answer Occurs when gas is cooled to become a liquid (occurs at 100C) Q: What is the critical point? Answer A point in a substance where it is reaching a temperature that the substance cannot exist in a liquid state Q: What is the critical pressure? Answer The lowest pressure required for a substance to exist in the liquid state Q: What is a crystalline solid? Answer A particle that is arranged in an orderly fashion of one of seven geometric patterns Q: What is an electrolyte? Answer Compounds that are ionic or very polar and dissolve into ions which conduct an electric current. Q: What is a fluid? Answer Particles are free to move (slide) around each other but will take the shape of any container it is in Q: What is ionization? Answer The amount of energy required to remove an electron from an atom. Takes place when a solvent causes the molecules of an electrolyte to dissociate into ions. Q: What is molality? Answer The moles of a solute that is present per kilogram of the solvent Q: What is molarity? Answer The moles of a solute that is present per litre of solution Q: What is a non-electrolyte? Answer Compounds that don't dissolve into ions and stays as a molecules when dissolved Q: What is a phase? Answer Any state of matter such as a solid, liquid, or gas Q: What is a strong electrolyte? Answer A substance that completely (100%) ionizes (Ex. HCl, HBr) Q: What is sublimation? Answer Occurs when solids are directly converted to a gas state Q: What is surface tension? Answer The surface acts like a thin elastic sheet. Occurs from an unbalanced cohesive forces where particles in the center of the liquid is attracted to other particles on all sides but the particles on the surface is attracted to other particles below them but aren't attracted to particles above them. This results in the surface particles being pulled inward. Q: What is the triple point? Answer The temperature and pressure that allows for solids, liquids, and gases to coexist Q: What is the vapour pressure? Answer The pressure that is exerted by freely translating vapour molecules above liquid molecules Q: What are weak electrolytes? Answer A substance that only partially ionizes (1-10%) (Ex. HF, NH3) Q: Explain how and why the presence of a solute affects the BP of water Answer A solute presence will lower the VP of a solvent by occupying some of the space near the surface of the water. This decrease in VP results in the increase of the temperature to raise the VP to atmospheric pressure. Therefore, elevating the BP Q: Why are liquids the least common state of mater? Answer Because there is a relatively small range of temperatures that liquids can exist in Q: What is the difference between evaporation and vapourization? Answer - Vapourization is the conversion of liquid particles to vapour at the BP of the material - Evaporation is the process of converting liquid particles to vapour at a temperature below the BP Q: Explain why the vapour pressure of a liquid increases with increased temperatures Answer As the temp increases the vibrations and rotations become intense enough to overcome the forces that keep the molecules together. The molecules begin to undergo translation motion allowing the molecules to convert to the vapour state and these exert a pressure above the still-existing liquid molecules called the VP of the substance Q: Explain water's concave meniscus in terms of cohesive and adhesive forces Answer - Cohesive forces are the attractions between particles of the same type - Adhesive forces are the attractions between particles of one type and another type - These cohesive and adhesive forces combine to cause liquids to form a meniscus in a glass tube. A liquid with strong cohesive tries to roll itself into a ball to minimize surface tension but it's also attracted to the walls of any tube by adhesive forces. Causing the water to form a concave meniscus Why does diffusion take place quickly in a gas, more slowly in a liquid, and not at all in a solid? Answer Diffusion is the non-energy-requiring movement of particles from regions of higher to lower concentrations. Diffusion in a liquid occurs more slowly than in a gas since the gas particles are moving more rapidly. Solids don't show the property of diffusion since the particles in a solid can only vibrate around a fixed point rather than move through the sample Differentiate between a crystal lattice and a unit cell Answer A crystal lattice is the orderly, repeating geometric pattern in which the particles of a crystalline solid are arranged. The unit cell is the smallest section of the crystal lattice having that arrangement of particles Why is liquid H2O more dense than ice H2O? Answer Ice has empty spaces between the molecules in its structures compared to H2O liquid List and describe the two components of a solution Answer - The minor component (aka solute) which is being dissolved in a solution - The major component (aka solvent) which is doing the dissolving in the solution Describe and define the Tyndall Effect Colloids can be distinguished from solutions by the use of a beam of light which is scattered by colloids but is un-scattered (organized) through the solution, known as Tyndall Effect Explain why sugar can be made to dissolve more quickly by grinding it to a fine crystal Grinding sugar to fine crystals increases the surface area of the crystal and this makes it dissolve more quickly b/c the solute particles dissolve by leaving the surface of their bulk structure which is in contact with the solvent Why does a bottle of a soda "fizz" when it's opened? When a bottle of soda is being opened, the pressure above the solution decreases and some of the CO2 bubbles off since a lower pressure allows the gas molecules in the solution to escape. Why does a temp increase usually increase the solubility of a solid? Dissolving most solids is an endothermic process (absorbs heat). Adding heat causes any dissolving process to change in the direction that consumes the added energy. For a solid or liquid, heat is absorbed as the solute dissolves in water so a solid or liquid is more soluble at higher temps. Explain how and why the presence of a solute affects the VP of a solvent The presence of a solute lowers the VP of a solvent b/c some of the solute particles occupy the space near the surface of the liquid replacing some of the solvent particles thereby decreasing the rate at which solvent particles can enter the vapour. Explain how and why the presence of a solute affects the FP of a solvent The presence of a solute lowers the FP of a solvent by forcing solvent molecules away from the growing solid crystal. In order. for the solvent molecules to reach the crystal and add themselves to the freezing solid, they must be slowed down to a lower kinetic energy by decreasing the temp. Describe the behaviour of a weak electrolyte and a strong electrolyte when placed in the conductivity apparatus which has the metal strips and light bulb. Solutions containing ions conduct electrical causing the light bulb to glow so the bulb would glow brightly with a strong electrolyte and dimly with a weak electrolyte. calorie (cal) unit of heat or other energy; the amount of energy required to raise 1 gram of water by 1 degree Celsius; 1 cal is defined as 4.184 J endothermic process chemical reaction or physical change that absorbs heat energy the capacity to supply heat or do work exothermic process chemical reaction or physical change that releases heat joule (J) SI unit of energy; 1 joule is the kinetic energy of an object with a mass of 2kg moving with a velocity of 1 m/s, 1 J = 1 kg m2/s and 4.184 J = 1 cal kinetic energy energy of a moving body, in joules, equal to 1/2mv^2 potential energy energy of a particle or system of particles derived from relative position, composition, or condition thermal energy kinetic energy associated with the random movement of atoms or molecules thermochemistry study of measuring the amount of heat absorbed or released during a chemical reaction or a physical change which of the following substances would you expect to have a relatively high chemical potential energy: Wood, Gasoline, Chalk, Water, Hydrogen Gas? Wood, gasoline, hydrogen gas heat (q) transfer of thermal energy between two substances surroundings all matter other than the system being studied system portion of matter undergoing a chemical or physical change being studied temperature intensive property of matter that is a quantitative measure of "hotness" and "coldness" When 50.0 mL of 0.10 M HCl(aq) and 50.0 mL of 0.10 M NaOH(aq), both at 22.0 °C, are added to a coffee cup calorimeter, the temperature of the mixture reaches a maximum of 28.9 °C degrees. Would the amount of heat measured for this reaction be greater, lesser, or remain the same if we used a calorimeter that was a poorer insulator than a coffee cup calorimeter? Explain your answer Lesser; more heat would be lost to the coffee cup and the environment and so ΔT for the water would be lesser and the calculated q would be lesser When solid ammonium nitrate dissolves in water, the solution becomes cold. This is the basis for an "instant ice pack". When 3.21 g of solid NH4NO3 dissolves in 50.0 g of water at 24.9 °C in a calorimeter, the temperature decreases to 20.3 °C. Would the amount of heat absorbed by the dissolution appear greater, lesser, or remain the same if the experimenter used a calorimeter that was a poorer insulator than a coffee cup calorimeter? Explain your answer. Lesser; heat from the environment would make ΔT smaller since the heat can affect the temperature of the reaction system, and the calculated q would be lesser chemical thermodynamics area of science that deals with the relationships between heat, work, and all forms of energy associated with chemical and physical processes enthalpy (H) is an energy like internal energy (E). The most important attribute of H is ΔH = Qp, the heat transferred at constant pressure expansion work (pressure-volume work) work done as a system expands or contracts against external pressure first law of thermodynamics internal energy of a system changes due to heat flow in or out of the system or work done on or by the system internal energy (E) sum of all kinetic and potential energies of the molecules in the system. It is the change in E that is useful to understand, and it is expressed through the first law of thermodynamics, ΔE = q + w. heat capacity (C) extensive property of a body of matter that represents the quantity of heat required to increase its temperature by 1 degree Celsius (or 1 kelvin) calorimeter a device used to measure the amount of heat absorbed or released during chemical or physical processes specific heat capacity (c) intensive property of a substance that represents the quantity of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius (or 1 kelvin) bomb calorimeter device designed to measure the energy change for processes occurring under conditions of constant volume; commonly used for reactions involving solid and gaseous reactants or products calorimetry process of measuring the amount of heat involved in a chemical or physical process Which can happen during a physical change? A) Molecules can move more rapidly and freely and change states B) The molecules in a substance break into smaller molecules. C) The molecules in a substance react with other molecules. D) The molecules in a substance are destroyed. Molecules can move more rapidly and freely and change states How many oxygen atoms are found in one molecule of nitric acid, HNO3? A) 1 B) 2 C) 3 D) 4 3 How many phosphorous atoms are found in three molecules of magnesium phosphate, 3Mg3(PO4)2? A) 1 B) 2 C) 3 D) 6 6 Which of the following is a synthesis reaction? A) 2H2 + O2 → 2H2O B) 2H2O2→ 2H2O + O2 C) CaCO3 → CaO + CO2 D) 2AgNO3 + Zn → 2Ag + Zn(NO3)2 2H2 + O2 → 2H2O Which is a chemical property of iron? A) Its tendency to react with oxygen B) Its melting point C) Its strength under compression D) Its hardness Its tendency to react with oxygen Which equation shows a physical change? A) Pb(NO3)2 (aq) + 2KI(aq) → 2KNO3(aq) + PbI2(s) B) HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) C) 2H2O(l) → 2H2(g) + O2(g) D) H2O(g) → H2O(s) H2O(g) → H2O(s) Which property of matter allows convection currents to form? A) Fluids rise if they are less dense than the matter around them. B) The molecules in solids do not vibrate very quickly. C) Electromagnetic waves carry energy. D) Liquids take the shape of their container. Fluids rise if they are less dense than the matter around them. A burning piece of coal glows red on a lab table. A student wants to prevent the coal from transferring heat to him. He sets up a metal shield between himself and the coal to prevent convection. Why will this not completely stop all of the heat transfer? A) The metal shield will heat up, and then heat the air on the student's side of the shield. B) The metal shield will cause more radiation to reach the student. C) The metal shield will not prevent heat transfer by conduction. D) The metal shield cannot block the flow of fluids. The metal shield will heat up, and then heat the air on the student's side of the shield. What must be true for any endothermic reaction? A) The chemical bonds of the products have more energy than the chemical bonds of the reactants. B) There are more products than there are reactants. C) There must be a phase change from solid to liquid or from liquid to gas. D) The reaction must take place in a sealed container held at constant volume. The chemical bonds of the products have more energy than the chemical bonds of the reactants. A student notices that a reaction takes place faster when the temperature is higher. Which best explains why this happens? A) At higher temperatures, the molecules collide more frequently. B) The heat of the solution breaks apart chemical bonds. C) As the particles move more quickly, they can more easily avoid each other. D) Catalysts cannot be effective at high temperatures. At higher temperatures, the molecules collide more frequently. A chemist finds that when platinum is added to a reaction, the reaction speeds up. He thinks the platinum may be acting as a catalyst. What measurement should the chemist make to determine whether it is a catalyst? A) Measure the mass of the platinum before and after the reaction. B) Measure the temperature of the solution before and after the reaction. C) Measure the change in volume of the solution. D) Measure the amount of gas released by the reaction. Measure the mass of the platinum before and after the reaction. Which would you most expect to be an unstable atom? A) A carbon (C) atom with 6 protons and 6 neutrons B) An iron (Fe) atom with 26 protons and 27 neutrons C) A helium (He) atom with 2 protons and 2 neutrons D) A curium (Cm) atom with 96 protons and 85 neutrons A curium (Cm) atom with 96 protons and 85 neutrons Americium-241 decays into neptunium-237. Which correctly describes this process of radioactive decay? A) An unstable nucleus decays into a more stable nucleus B) Energy in the nucleus is converted into mass C) The strong nuclear force splits the nucleus apart. D) The atom loses four protons. An unstable nucleus decays into a more stable nucleus Gamma rays are often used to kill microorganisms in food, in an attempt to make the food safer. Some people contend that this irradiated food is actually less safe to eat. Which, if true, would most effectively dispute their idea? A) Irradiated food only emits alpha particles, which are harmless. B) Irradiated food is shown to not be radioactive. C) Irradiated food only contributes to background radiation. D) Irradiated food has molecules that undergo transmutation. Irradiated food is shown to not be radioactive. How do the forces in nuclear and chemical reactions differ? A) Both reactions only need to overcome weak electrostatic forces. B) Chemical reactions must overcome the strong nuclear force C) Nuclear reactions must overcome much stronger forces. D) Nuclear reactions must overcome intermolecular forces. Nuclear reactions must overcome much stronger forces. Why do chemical reactions not produce radioactive particles? A) Chemical reactions make the nuclei of atoms more stable. B) Chemical reactions only release gamma rays. C) Only electrons are involved in chemical reactions. D) Mass is not conserved in chemical reactions. Only electrons are involved in chemical reactions. Which of these statements about power plants is true? A) Coal-fired plants give off pollution even when operating correctly. B) Nuclear plants give off radiation even when operating correctly. C) Coal-fired plants give off no pollution when operating correctly. D) Nuclear plants give off greenhouse gases when operating correctly. Coal-fired plants give off pollution even when operating correctly. Which is the most valid reason a group of people might oppose the storage of spent fuel rods in their community? A) The fuel rods will remain radioactive for a long time. B) The fuel rods contribute to global warming. C) The fuel rods may cause a nuclear meltdown. D) The fuel rods do not emit radioactive particles. The fuel rods will remain radioactive for a long time. Which of the following aspects of biotechnology is not considered to be a moral or ethical issue? A) Research and testing on animals B) Cloning living material C) Reducing research cost D) Damaging the environment Reducing research cost Which is one way that an advance in biotechnology can produce unintended consequences that harm the environment? A) Genetically modified plants require less water to grow. B) Patients using insulin pumps live longer than those without the pumps C) Pesticides can prevent insects from destroying crops. D) Genes implanted into a species of plant can spread to other plants. Genes implanted into a species of plant can spread to other plants.