Discuss why the constituents of an aqueous solution can only be separated by evaporation and the concentration of the solute in the solution calculated in % (m/v) and in molarity

You prepare a solution by adding 20.0 g Urea [(NH₂)₂CO] to 125 g water at 25.0^oC & vapor pressure 23.76 torr.

       The solution vapor pressure is 22.67 torr. Calculate the molecular weight of urea.

     X_H2O = ________   moles H₂O = ________    X_solute = ________      moles urea = ________    molar mass = ________

No other data provided

3. The cations on an exchangeable site of a 40 g soil were displaced by repeatedly washing by a salt and found to be 40 mg Ca+2, 11.5 mg Na+1, 39 mg K+1, 12 mg Mg+2, and 9 mg Al+3. The pH of the soil was 5.0. Calculate the CEC (cmolc/kg), percentage base saturation (PBS) and percent acidic saturation (PAC) per kg of the soil.

4. A give soil has a CEC of 12.50 cmol of charge per kg of soil. If 70%, 15%, 10% and 5% of the CECis occupied by Ca+2, K+1, Mg and Na+1 , respectively, calculate the weight (grams) of Ca, K, Mg and Na in the soil.

5. A given soil contains the following colloids: 1.0% humus (CEC=200), 30% kaolinite (CEC=5), 5%smectite (montmorillonite) (CEC=80), 10% illite (CEC=20), 5% mica (CEC=70) and 49% sesquioxides (CEC=2). Calculate the CEC of the soil? Which colloids contributed the most and which contributed the least? (All CEC are in molc/kg soil).

6. Calculate the amount of pure CaCO3that could theoretically neutralize the H+ in one-year acid rain if a 1-hectare (ha) site received 200 mm of rain per year and the average pH of the rain was 5.0.

7. Calculate the pH and pOH of a soil with the following H+ concentrations: (a) 0.0000001M (b) 0.00001M (c) 0.005M? Which soil is relatively most acidic? Most basic?

8. Determine the calcium carbonate equivalent (CCE) of the following compounds: (amount that has the same neutralizing value as 100 g pure CaCO3) (a) KOH (b) Mg(OH)2 (c) and CaMg(CO3)2.

9. How many grams of limestone with a CaCO3 equivalent of 100% would you need to apply to an acidic soil with 85% exchangeable Al saturation to reduce it to 10%? The CEC of the soil is 12.5cmolc/kg.

10. How many grams of gypsum (CaSO4.2H2O) would you need to reclaim a sodic soil with an exchangeable sodium percentage (ESP) of 80% to reduce to it to 50%? The CEC of the soil is 12.5cmolc/kg.

Summarize main factors that have influence on SN2 type reactions: reactivity of the nucleophile, nature of the leaving group, structure of the alkyl portion of the substrate and the nature of the solvent :) can you go into each of these in a short paragraph <3

Sulfur dioxide (SO₂ ) is a gas that is a polluant responsible for acid rain. It can be formed by the following reaction:

               H₂S _(g) + O_{2 (g)} ? SO_2(g) + H₂O_(g)   (unbalanced)

What volume of 4M H₂S , in L, is required to react with excess O₂ to produce enough SO₂ to fill a cylinder that is 58ft long and has a diameter of 14ft at a pressure of 551 torr and 24?C?

What is the reaction order with respect to initiator concentration (e.g. first order, second order, etc.) for each of the following steps:

a. Initiation

b. Propagation

c. What is the relationship between initiator concentration and critical chain length?

If a gas mixture at 298 K, which contains 90% N2, 5% H2O, and 5% O2, is instantaneously heated to 2000 K, plot the NO concentration as a function of time.

Plot the NO concentration as a function of time, if the mixture is heated to 3000K.

what is meant by stokes shift and anti stokes shift in spectroscopy?

How would the accuracy of your determined Keq change if all your volume measurements were made with graduated cylinders rather than pipets?

What amount of solid NaOH must be added to 1.0 L of a 0.12 M H2CO3 solution to produce a solution with [H+]= 3.0×10−11 M ? There is no significant volume change as the result of the addition of the solid.

The leaves of the rhubarb plant contain high concentrations of diprotic oxalic acid (HOOCCOOH) and must be removed before the stems are used to make rhubarb pie. If pK_a1 = 1.23 and pK_a2 = 4.19, what is the pH of a 0.0205 M solution of oxalic acid?

The following is a list of drugs. For this assignment, use any resources available to you to find the structures and the pKa of these drugs. Identify the functional groups on each drug that will readily ionize under the appropriate pH conditions. Finally, determine the degree of ionization of the drug at physiological pH (7.4).

• MDMA
• Amphetamine
• Butalbital
• Hydrocodone
• Carisoprodol

I understand how to find the functional groups. I need help understanding how to calculate the degree of ionization. With the explanation of at least one of the drugs I should be able to finish the other drugs on my own. Thank you in advance!