Quiz 7: States Of Matter And Intermolecular Forces

Heat is the correct answer because it is the primary factor that causes matter to change from one state to another. When heat is applied to a substance, it increases the kinetic energy of its particles, causing them to move faster and break the intermolecular forces holding them together. This results in a change of state, such as solid to liquid (melting) or liquid to gas (evaporation). Heat is essential in the process of changing the physical state of matter.

A solid has a definite shape and a definite volume because its particles are closely packed together and have strong intermolecular forces. This arrangement restricts the movement of the particles, causing them to vibrate in fixed positions. As a result, solids maintain their shape and volume.

Water in its gas state is called water vapor or steam. When water evaporates, it turns into a gas and becomes water vapor. This is commonly seen when water boils, and steam is produced. Water vapor is invisible, but it can condense into visible water droplets when it cools down, forming clouds or fog. Therefore, the correct answer is water vapor (steam).

The change in state from a solid to a liquid is called melting. This occurs when heat is applied to a solid substance, causing the particles to gain energy and vibrate more rapidly, eventually breaking the bonds that hold them in a fixed position. As a result, the solid substance transitions into a liquid state, where the particles are able to move more freely while still maintaining their cohesive properties.

Freezing is the process in which a substance changes its state from liquid to solid. During freezing, the particles in a liquid slow down and come closer together, forming a rigid structure. This results in the formation of a solid.

Evaporation is the process by which a substance changes from a liquid state to a gaseous state. This occurs when the molecules of the liquid gain enough energy to overcome the attractive forces holding them together, allowing them to escape into the surrounding environment as gas. This process is commonly observed when water or other liquids are heated, causing them to evaporate and form water vapor or gas. Therefore, evaporation is the correct answer for the given question.

In a solid, the molecules are tightly packed together and have strong intermolecular forces holding them in place. Due to this close proximity, the molecules are able to vibrate against each other. This vibration is responsible for the solid's rigidity and ability to maintain its shape. Therefore, the statement that the molecules in a solid stay closely and vibrate against each other is true.

A gas is a state of matter that does not have a definite shape or volume. Unlike solids and liquids, which have distinct boundaries and occupy a fixed amount of space, gases can expand to fill any container they are placed in. The particles in a gas are loosely packed and move freely, allowing them to spread out and fill the available space. This lack of definite shape and volume is a defining characteristic of gases.

A liquid is a state of matter that has no definite shape, meaning it can take the shape of its container, but it does have a definite volume, meaning it maintains a specific amount of space. Unlike solids, which have both a definite shape and volume, and gases, which have neither a definite shape nor volume, liquids have the ability to flow and are characterized by their ability to pour and be poured. Therefore, a liquid fits the description of having no definite shape, but a definite volume.

Condensation refers to the process of a gas changing into a liquid state. This occurs when the temperature of the gas decreases, causing the gas particles to lose energy and come closer together, forming a liquid. This change in state is commonly observed when water vapor in the air cools down and forms water droplets on a cold surface, such as dew forming on grass in the morning or water droplets forming on the outside of a cold glass.

In a gas, the molecules are in constant motion and have high kinetic energy. This causes them to move rapidly and randomly, colliding with each other and the walls of the container. As a result, they spread out to fill the entire available space within the container. Therefore, the statement "The molecules in a gas move fast and spread out to fill the entire container" is true.

H-O, H-N, H-F=Hydrogen Bonds (Weaker than Ion-dipole forces). H and O makes an H-O bond, so the IMF's between the molecules are hydrogen bonding.

It is hydrogen bonding because there is attraction between a hydrogen from one molecule with an oxygen from another molecule. Hydrogen bonding is a strong IMF, causing ethanol exist as a liquid at room temperature.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding;
Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest). NH3 and HF have hydrogen bonding because they have H-F/H-O/H-N bonded. HBr is polar, so it's just dipole-dipole. CH4 is nonpolar, so it's London Dispersion Forces. Hydrogen Bonds are stronger IMF's than dipole-dipole and London Forces are, so NH3 and HF have higher boiling points as a result.

Higher Boiling Point=Stronger Intermolecular Forces.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces. Since CCl4 is nonpolar (symmetrical distribution of charge overall), this qualifies as having London Dispersion Forces.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding;
Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest). HF has H-F, so it has hydrogen bonding. HCl and HBr are polar molecules (asymmetrical distribution of charge) without H-F, H-N, or H-O, so they have dipole-dipole forces. H2 is a nonpolar molecule (symmetrical distribution of charge), so it has London forces. Hydrogen bonding in H-F is the strongest IMF (stronger than dipole-dipole and London forces), so HF will have the highest boiling point, because it has the strongest IMF's of the four molecules.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest). NH3 has H-N, so it has hydrogen bonding. AsH3 and PH3 are polar molecules (asymmetrical distribution of charge) without H-O, N-H, and H-F, so they have dipole-dipole forces. Hydrogen bonding is stronger than dipole-dipole forces are, so NH3 has the highest boiling point, because it has the strongest IMF's out of the three molecules.

H-O, H-N, H-F=Hydrogen Bonds (Weaker than Ion-dipole forces). Both hydrogen fluoride (HF) and ammonia (NH3) contain H-F, H-O, or H-N bonds, so the IMF's between them are hydrogen bonds.

Ionic Compound + Water=Ion-Dipole Forces (strongest IMF's); H-O, H-N, H-F=Hydrogen Bonds (Weaker than Ion-dipole forces); CuO in water is an ionic compound in water, so it has ion-dipole forces. On the other hand, water has H-O, so it has hydrogen bonding. Ion-dipole has stronger IMF's and, therefore, a higher boiling point.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest IMF's, lowest boiling point); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest IMF's, highest boiling point). CF4 is nonpolar (symmetrical distribution of charge), so it has London forces. CH3Cl is a polar molecule (asymmetrical distribution of charge) without H-F, H-O, or H-N, so it has dipole-dipole forces. CH3OH has O-H in its structure, so it has hydrogen bonding. Na2O (aq) has an ionic compound, Na2O, dissolved in water (aq), so it has ion-dipole forces. In order, London forces are weakest, dipole-dipole forces are stronger, hydrogen bonds are even stronger than dipole-dipole, and ion-dipole forces are strongest.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces. Since PH₃ is a polar molecule (it's asymmetrical overall, in terms of charge distribution) without H-F, H-O, or H-N, this qualifies as having dipole-dipole forces.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding
Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest). H2Se and CO have dipole-dipole forces because they are polar molecules without H-F/H-O/H-N. CF4 and CO2 are both nonpolar, so they have London Dispersion Forces. Dipole-Dipole Forces are stronger IMF's than London Forces are, so H2Se and CO have higher boiling points as a result.

Molecules in a liquid do not spread out to fill the entire container. Unlike gases, liquids have a definite volume and take the shape of the container they are in, but the molecules still remain close together. The movement of liquid molecules is more restricted compared to gases, as they have stronger intermolecular forces holding them together.

Nonpolar Molecules (Symmetrical distribution of charge)=London Dispersion (weakest IMF's, lowest boiling point); Polar Molecules (Asymmetrical distribution of charge)=Dipole-Dipole Forces; Molecules with H-F, H-O, or H-N (because of big ∆EN)=Hydrogen Bonding; Saltwater (ionic compound and water)=Ion-Dipole Forces (strongest IMF's, highest boiling point). CO2 is nonpolar (symmetrical distribution of charge), so it has London forces. H2S is a polar molecule (asymmetrical distribution of charge) without H-F, H-O, or H-N, so it has dipole-dipole forces. HF has F-H in its structure, so it has hydrogen bonding. NaF is an ionic compound, so it has ion-ion opposite attractions. In order, London forces are weakest, dipole-dipole forces are stronger, hydrogen bonds are even stronger than dipole-dipole, and ion-ion forces are strongest.