Why does the antifreeze ethylene glycol, HO-CH2-CH2-OH, molar mass 62.07 g/mol, have a much higher higher boiling point (197.6°C) than propanol (97.4°C), CH3-CH3-CH2-OH, molar mass 60.09 g/mol, even though they have similar molar masses?

As a technician in a large pharmaceutical research firm, you need to produce 450. mL of a potassium dihydrogen phosphate buffer solution of pH = 6.91. The pKa of H2PO4− is 7.21. You have the following supplies: 2.00 L of 1.00 M KH2PO4 stock solution, 1.50 L of 1.00 M K2HPO4 stock solution, and a carboy of pure distilled H2O. How much 1.00 M KH2PO4 will you need to make this solution? (Assume additive volumes.)

What is the Henry's law constant for CO2 at 20∘C?

Express your answer to three significant figures and include the appropriate units.

What pressure is required to achieve a CO2 concentration of 9.40×10⁻² M at 20∘C?

Express your answer to three significant figures and include the appropriate units.

At 1 atm, how many moles of CO2 are released by raising the temperature of 1 liter of water from 20∘C to 25∘C?

Express your answer to four decimal places and include the appropriate units.

The Ostwald process is used commercially to produce nitric acid, which is, in turn, used in many modern chemical processes. In the first step of the Ostwald process, ammonia is reacted with oxygen gas to produce nitric oxide and water. \(4NH_{3}(g)+5O_{2} --> 4NO+6H_{2}O(g)\) What is the maximum mass of H2O that can be produced by combining 72.0 g of each reactant?

Calculate the amount of sodium oxalate needed to react with 1.5 ml of 0.02M of KMNO4 solution.

The solutions at the two Pb electrodes of a concentration cell were prepared as follows:

Cell A: A mixture of 1.00 mL of 0.0500 M Pb(NO₃)₂ with 4.00 mL of 0.0500 M KX (the soluble potassium salt of an unspecified monovalent ion X^-).
Some PbX₂(s) precipitates.

Cell B: 5.00 mL of 0.0500 M Pb(NO₃)₂.

The cell potential was measured to be 0.05600 V at 25 °C.

1.By use of the Nernst equation, determine the concentration (M) of Pb²⁺ in the solution of Cell A.

2.In Cell A, how many moles of X^- have reacted with Pb²⁺?

3.What is the concentration (M) of X^- in the solution of cell A.

4.Calculate K_sp of PbX₂.

Ag⁺ + Cl^- ↔ AgCl(s)

1.004 g of an impure mixture containing Cl- was dissolved to 100.0 mL. 10.00 mL of this solution required 22.97 mL of 0.05274 M AgNO3 to reach end point. What is the weight percent of Cl- in the unknown solid?

consider the isoelectronic ions Cl- and K+. Which ion is smaller?

ssuming the core electrons contribute 1.00 and valence electrons contribute nothing to the screening constant, S, calculate Zeff for these two ions.

Repeat this calculation using slater's rules to estimate the screening constant, S. For esoelectronic ions how are effective nuclear charge and ionic radius related?

Sulfide in a water sample is coulometrically titrated with iodine (H2S + I2 ----> S + 2H+ + 2I-). If a 10.00 mL aliquot of the water sample requires a current of 0.75 A for 5.4 minutes to reach the end point, what is the molarity of the sulfide in the water sample?

(A) 0.5036 (B) 0.1259 (C) 0.0051   (D) 0.0013

A 0.1358-g portion of potassium iodate (MW 214.00), about 2 g of potassium
iodide, and 2 mL of 6 M hydrochloric acid were dissolved in 25 mL of distilled
water. The triiodide formed during the ensuring reaction was titrated to the
starch end point with 31.94 mL of a thiosulfate solution. A 25.00-mL triiodide
sample solution was titrated to the end point with 21.33 mL of the standardized
thiosulfate solution. Calculate the concentrations of the thiosulfate solution and
the triiodide solution.

The density of liquid oxygen at its boiling point is 1.14 kg/L , and its heat of vaporization is 213 kJ/kg .

How much energy in joules would be absorbed by 2.0 L of liquid oxygen as it vaporized?

Express your answer to two significant figures and include the appropriate units.

Water's heat of fusion is 80. cal/g , and its specific heat is 1.0calg??C .

Some velomobile seats have been designed to hold ice packs inside their cushions. If you started a ride with ice packs that held 1400 g of frozen water at 0 ?C , and the temperature of the water at the end of the ride was 32 ?C , how many calories of heat energy were absorbed?

Express your answer to two significant figures and include the appropriate units.

Water's heat of fusion is 80. cal/g , its specific heat is 1.0calg??C, and its heat of vaporization is 540 cal/g .

A canister is filled with 390 g of ice and 100. g of liquid water, both at 0 ?C . The canister is placed in an oven until all the H2O has boiled off and the canister is empty. How much energy in calories was absorbed?

Express your answer to two significant figures and include the appropriate units.

For a particular redox reaction NO is oxidized to NO3– and Ag^+ is reduced to Ag. Complete and balance the equation for this reaction in basic solution. Phases are optional.

Consider the following reaction at constant P. Determine the value of ΔSsurroundings at 298 K? Predict whether or not this reaction will be spontaneous at this temperature. N₂(g) + 2 O₂(g) → 2 NO₂(g); ΔH = +66.4 kJ

(Please show work and thank you for taking the time to answer.)