Calculate [H3O ], [ClO4–], and [OH–] in an aqueous solution that is 0.130 M in HClO4(aq) at 25 °C.

[H^+]=

[ClO4^-]=

[OH^-]=

Is the solution acidic, basic or neutral?

The standard free energy of activation of a reaction A is 75.1 kJ mol–1 (17.9 kcal mol–1) at 298 K. Reaction B is one million times faster than reaction A at the same temperature. The products of each reaction are 10.0 kJ mol–1 (2.39 kcal mol–1) more stable than the reactants. (a) What is the standard free energy of activation of reaction B?

You are making sandwiches again. This time, one double-decker sandwich consists of 3 slices of bread, 2 chicken slices, and 4 tomato slices. Suppose that you have 3.15 kg of slices of bread, 1.52 kg of chicken slices, and 1.92 kg of tomato slices.You also know that a dozen slices of bread weigh 360 g, a dozen slices of chicken weigh 240 g, and a dozen slices of tomato weigh 144 g. (One dozen is 12). (a) What is the maximum number of complete sandwiches you can make with the quantities you have available? (b) Which ingredient is the limiting one? (c) What is the mass (in grams) of one sandwich?

how many photons are produced in a laser pulse of 0.558 J at 431 nm?

1)The minimum frequency of light needed to eject electrons from a metal is called the threshold frequency, ν0. Find the minimum energy needed to eject electrons from a metal with a threshold frequency of 4.55 × 1014 s–1.

2)With what maximum kinetic energy will electrons be ejected when this metal is exposed to light with a wavelength of λ = 265 nm?

3. Fluorine reacts with vanadium to produce vanadium(V) fluoride according to the following equation: 5 F2 (g) + 2 V (s) → 2 VF5 (l) (a) How many moles of vanadium are needed to react completely with 0.1917 g of fluorine? (b) What is the maximum theoretical mass of vanadium(V) fluoride that can be produced? (c) If 0.225 g of vanadium(V) fluoride is obtained, what is the percent yield of VF5 (l)? Molar masses (g/mol): F2 38.00 VF5 145.93

The questions below refer to a solution of butanoic acid, CH3(CH2)2-COOH, in water. The solution was formed by adding 1.15 g of butanoic acid to enough water to make 100 mL of solution at 298K.

1. What is the initial butanoic acid concentration in the solution in moles per liter?

2. What is the pH of this solution?

3. How many mL of a 1.095 M NaOH solution would have to be added to the butanoic acid solution in order to completely neutralize the acid?

4. What will be the pH of the solution at the equivalence point, i.e. when all of the acid has reacted with the NaOH?

Calculate the pH in 0.780 M CH3CO2H.

The optimal pH for condensing an amine with a carbonyl group to create an imine is pH = 5-6. a. Show a predicted reaction mechanism using curved arrows to show how this reaction occurs. b. If the pH were higher, which steps would be more difficult? Explain. c. If the pH were lower, which steps would be more difficult? Explain.

A 1.100 L sample of HCl gas at 25∘C and 732.0 mm Hg was absorbed completely in an aqueous solution that contained 6.900 g of Na2CO3 and 265.0 g of water.

What is the pH of the solution?

What is the freezing point of the solution?

What is the vapor pressure of the solution? (The vapor pressure of pure water at 25 ∘C is 23.76 mm Hg.)

“Condensation” polymerization involves the formation and loss of a small molecule (such aswater) as each monomer is added to the growing polymer chain. What small molecule would be formed by the reaction of sebacoyl chloride and hexamethylenediamine?

At which pH would the net electric charge of tyrosine be zero, given that its -COOH group has a pKa of 2.20, its –NH3+ group has a pKa of 9.11, and its R group has a pKa of 10.07?

2(a). Describe how adding a solution of KOH to the original sulfide precipitate results in the separation of Sn4+ ion from the other Group II cations.

2(b). Why wouldn’t a weak base, such as aqueous NH3 work just as well as aqueous KOH in (a)?

4. When perturbing the equilibrium with heating and cooling, how many times do you think the equilibrium can be shifted before it stops working? Why? How about modification of the equilibrium through changes in concentration?

The vapor pressure of diethyl ether (ether) is 463.57 mm Hg at 25°C.

How many grams of testosterone, C₁₉H₂₈O₂, a nonvolatile, nonelectrolyte (MW = 288.4 g/mol), must be added to 192.8 grams of diethyl ether to reduce the vapor pressure to 458.70 mm Hg ?

diethyl ether = CH₃CH₂OCH₂CH₃ = 74.12 g/mol.