Which of the following is likely to have the greatest exothermic hydration enthalpy? A) Sr2+ B) Na+ C) Mg2+ D) Ca2+ E) K+

Which pair of aqueous solutions is given in order of increasing freezing point?

(1) 0.010m Na3PO4 < 0.030m NaCl

(2) 0.020m NaI < 0.030m glucose

(3) 0.010m CaCl2 < 0.020m KCl

(4) 0.010m Na3PO4 < 0.020m Na3PO4

(5) 0.020m glucose < 0.010m CaCl2

If a solution containing 84.670 g of mercury(II) nitrate is allowed to react completely with a solution containing 12.026 g of sodium sulfide, how many grams of solid precipitate will be formed?How many grams of the reactant in excess will remain after the reaction?

1. In this distillation experiment we start the experiment with 10 mL of liquid mixture ofcyclohexane and toluene. However, it is not possible to obtain all 10 mL back under thecurrent procedure particularly for fractional distillation. Explain why that is the case for distillation and in particular for fractional distillation.

2. How could you modify the experiment and collect all 10 mL of the startingmaterials.

3. Plot a theoretical distillation curve of temperature (y-axis) vs. volume in mL (x-axis) fora 15 mL of a mixture containing 60% 1-propanol and 40% 2-propanol. Are these twocompounds easier to separate by distillation than cyclohexane and toluene? Explain youranswer.

4. In this experiment you were asked to collect two fractions and early fraction and a latefraction. Which of the two fractions would be richer in cyclohexane? Would there be adifference between the percent of cyclohexane in the fractions collected from fractionalvs. simple distillation.

5. What method of purification would you use to purify methanol from a solution ofmethanol and NaCl? Be specific and explain your choice of method.

20 mL of .10 M HC2H3O2l solution in a small beaker is titrated with .10 M NaOH solution (at 25 C). Calculate the value of the equilibrium constant for this titration. Is it safe to assume that this titration reaction goes essentially to completion? Explain.

a bag of "bulldog ice melter" is made up of a mixture of calcium chloride and magnesium chloride, but the ratio of salts in not listed on the bad. A sample of salt mixture is added to 1000g of water. The concentration of chloride ions in the resulting solution is 2M. What is the molarity of the ions in this solution?

a. A student performed Part 3 of the lab. A 360 ppm Ca2+ standard required 22.34 mL of EDTA to reach the end point. Some well water from my grandma’s farm required 15.47 mL of EDTA. By proportionality to the 360 ppm standard, determine the total concentration of Ca2+ (in ppm) in my grandma’s well water?

b. What is the molarity of Ca2+ in the well water? (ppm stands for parts per million. 100 ppm Ca2+ represents 100 grams of Ca2+ in 1,000,000 grams of solution. Assume that the density of the solution is 1.00g/mL).

c. If the daily recommended amount of calcium in an adult’s (age 19 – 50) diet is 1,000 mg, how many liters of water would you need to consume to fully meet your daily calcium needs? (See http://www.nlm.nih.gov/medlineplus/ency/article/002412.htm for reference information.)

How will you determine the relationship between acid/base molarity and ∆H? Write specific equations for the reactions that you will use in this determination (at least 3). What variables will you need to keep constant in this determination?

--Given Values--
Atomic Radius (nm) = 0.116
FCC Metal = Gold
BCC Metal: = Sodium
Temperature ( C ) = 1017
Metal A = Tin
Equilibrium Number of Vacancies (m^-3) = 6.02E+23
Temperature for Metal A = 369
Metal B = Gallium

I need help with 3, 4, 6, 7, 11, 12. Am I entering the notations incorrectly?

) If the atomic radius of a metal is the value shown above and it has the face-centered cubic crystal structure, calculate the volume of its unit cell in nm³? Write your answers in Engineering Notation.  
        Your Answer =Correct! Exact Answer= 35.3E-3 +/- 1.00E-03%
2) What is the atomic packing factor for the BCC crystal structure?  
        Your Answer = Correct!
3) Find the theoretical density for the FCC Element shown above in g/cm³. Write your answer to the ten thousandths place (0.0000):  
        Your Answer = Incorrect.
4) Calculate the atomic radius, in nm, of the BCC Metal above utilizing the density and the atomic weight provided by examination booklet - Write your answer with 4 significant figures:  
        Your Answer = Incorrect.
5) Calculate the fraction of atom sites that are vacant for copper (Cu) at the temperature provided above. Assume an energy for vacancy formation of 0.90 eV/atom:  
        Your Answer =Correct! Exact Answer= 3.05E-04 +/- 1.00E-05%
6) Repeat the calculation in question 5 at room temperature (25 C):  
        Your Answer = Incorrect.
7) Calculate the energy (in eV/atom) for vacancy formation for the Metal A and the equilibrium number of vacancies at the temperature provided above - Write your answer with 4 significant figures:  
        Your Answer = Incorrect.
8)Calculate the number of atoms per cubic meter in Metal B (units atoms/m³). Write your answer with 4 significant figures :
        Your Answer =Correct! Exact Answer= 5.0961E+28 +/- 1.00E+26%
9) What is the composition, in atom percent, of an alloy that contains a) 36 g Metal A and b) 47 g Metal B? Composition for Metal A (%):  
        Your Answer =Correct! Exact Answer= 31.02769217 +/- 1.00E-01%
10) What is the composition, in atom percent, of an alloy that contains a) 36 g Metal A and b) 47 g Metal B? Composition for Metal B (%):  
        Your Answer =Correct! Exact Answer= 68.97230783 +/- 1.00E-01%
11) What is the composition of Metal A in atom percent, if the alloy consists of 4.5 wt% Metal A and 95.5 wt% of Metal B?  
        Your Answer = Incorrect.
12) What is the composition of Metal B in atom percent, if the alloy consists of 4.5 wt% Metal A and 95.5 wt% of Metal B?  
        Your Answer =

Write a net ionic equations to show how each of hte buffer mixtures below would neutralize added H+ and OH-

a. C6H5COOH and NaC6H5COO H+ + _______ ---> _____________

OH- + _______----> _____________

H+ + ________-----> _____________

b. NH4Cl and NH3 H+ + ________ ------> _____________

OH- + ________-------> ______________

Balance the following redox reaction in basic solution then answer these questions about the balanced reaction. Cl2(g) → Cl-(aq) + ClO-(aq)

Part 1: What is the stoichiometric coefficient in front of Cl2 in the balanced reaction?

Part 2: What is the stoichiometric coefficient in front of OH- in the balanced reaction?

Part 3: What is the stoichiometric coefficient in front of Cl- in the balanced reaction?

Part 4: What is the stoichiometric coefficient in front of OCl- in the balanced reaction?

Part 5: What is the stoichiometric coefficient in front of H2O in the balanced reaction?

Draw a diagram that illustrates the hyperconjugation that explains these phenomena:

- more substituted alkenes have lower heats of hydrogenation

- more substituted carbocations are more stable

- staggered conformations are lower in energy than eclipsed

- allylic SN2 is faster than non-allylic

Be sure to use shading to indicate the location of nodes and use arrows to show overlap.

Thank you!!!

Suppose we are running a Gas Chromatography for a mixture of standard alkanes (C5-C18) in hexane solvent. How do we determine which alkanes are present in the standard from the chromatogram?

Which following molecules expected to be polar? SiBr4 CO2 SO2 BF3

Explain why carbocations are higher in energy than oxonium ions, despite oxygen being more electronegative than carbon. Second, state four factors that account for the relative stabilities of carbocations.