One way to calculate enthalpy is by subtracting the strength of the bonds broken in the reactants from the strength of the bonds formed in the products. If the first value is greater than the second value, the overall enthalpy change will be negative.

A buffer is made up of either a weak acid and its salt or a weak base and its salt. Option (B) has a strong acid and strong base, option (C) has a strong acid and its salt, and option (D) has a weak acid and a weak bas

The farther away an electron is from the nucleus, the less ionization energy that is required to eject it, and as a result, the electron will have more kinetic energy after it is ejected. The 3p subshell is the farthest one that a neutral chlorine atom would have electrons in. Beware of choice (D); chlorine does not have a 3d subshell.

There is 1 mole of N₂, 1 mole of Ar, and 2 moles of water in the container. The mole fraction of nitrogen is 1/4 = 0.25.

P_N2 = (X_N2)(P_total)

P_N2 = (0.25)(2.0) = 0.50 atm

Water is polar, and using "like dissolves like," we know that only polar solvents will be able to fully mix with it to create a homogenous solution.

When a covalent substance undergoes a phase change, the bonds between the various molecules inside the substance break apart.

In an endothermic reaction, heat is transferred into the reaction system.

The overall rate law is always equal to the rate law for slowest elementary step, which can be determined using the coefficients of the reactants. In this case, rate = k[NO₂][F₂]. To get the overall order, we add the exponents in the rate law. 1 + 1 = 2

Both are nonpolar, but propane has a lot more electrons and thus is more polarizable than ethene.

Moving across a period, atomic size decreases. Therefore, atom Z will be farthest to the right (have the most protons), and thus will have the highest electronegativity value.

In phase I, an increased temperature means the molecules are moving faster and will spread out more, leading to an increased volume. For the volume to remain constant in phase II, either both pressure and volume have to remain constant, or they both have to increase or decrease together, as they are inversely proportional.

None of the options would decrease the rate of reaction, which would be required for the half-life of the reactant to increase.

Nitrogen only has two shells of electrons while phosphorus has three, making nitrogen smaller and more able to attract additional electrons, meaning a higher electronegativity. Nitrogen and oxygen both have two shells, but oxygen has more protons and an effective nuclear charge of +6 vs. nitrogen's effective nuclear charge of +5. Thus, oxygen has a higher electronegativity.

Adding (or removing) any species in an equilibrium reaction does not change the equilibrium constant and also does not change the magnitude of the Gibbs free energy at standard conditions.

The reaction is endothermic, meaning energy is a reactant (appears on the left side of the equation). Adding stress to the left side increases the rate of the forward reaction, creating more products.

Use M₁V₁ = M₂V₂ to determine the necessary volume of stock solution.

(18.0 M)V₁ = (3.0 M)(1.0 L)

V₁ = 0.167 L = 167 mL

When creating solutions with acid, you always add some water first, as the process is extremely exothermic and the water will absorb the generated heat.

Vapor pressure is dependent on intermolecular forces. The weaker the IMFs are, the easier it is for molecules to escape from the surface of the liquid. To begin, polar molecules have stronger IMFs than nonpolar molecules. Methanol and ethanal are both polar, but methanol has hydrogen bonding meaning it has stronger IMFs (and thus a lower vapor pressure) than ethanal. Ethene and propane are both nonpolar, but propane is larger meaning it is more polarizable than ethene and thus has stronger IMFs and lower vapor pressure.

Between trial 1 and 3, the concentration of NO doubled while the concentration of Br₂ held constant, and the rate went up by a factor of four. So, the reaction is second order with respect to NO. Between trial 1 and 2, the concentration of NO was held constant while the concentration of Br₂ doubled, and the rate went up by a factor of two. Thus, the reaction is first order with respect to Br₂.

The weaker the O-H bond is in an oxoacid, the stronger the acid will be because the H⁺ ions are more likely to dissociate. The O-F bond in HOF is stronger than the O-Cl bond in HOCl because fluorine is smaller (and thus more electronegative) than chlorine. If the O-F bond is stronger, the O-H bond is correspondingly weaker, making HOF the stronger acid.

The oxidation state of nitrogen in NO is +2. If the nitrogen is reduced, that value must get more negative. The oxidation state of nitrogen in N₂ is 0, so that fits the bill. The oxidation state on the nitrogen in the other choices is greater than +2.

14.0 g of Si is 0.50 mol, and 32.0 g of oxygen is 2.0 mol. Converting that to a whole number ratio gives us 1 mol of Si for every 4 moles of O.

Increasing the pressure in an equilibrium reaction with any gas molecules causes a shift to the side with less gas molecules-in this case, the product.

Potassium's first valence electron is in the fourth energy level, but both chlorine and argon's first valence electron is in the third energy level.

Temperature in Kelvins is a measure of kinetic energy. When that temperature doubles, so does the kinetic energy. However, a doubling of the temperature in Celsius, while increasing the amount of kinetic energy, would not double it.