Questions
Using the following atomic weights and that the density of cyclohexanol is 0.96, what is the...

Using the following atomic weights and that the density of cyclohexanol is 0.96, what is the % yield of a reaction that starts with 6.7 mL of cyclohexanol and ends with 2.3 g of cyclohexene?

C = 12, H = 1, O = 16

In: Chemistry

(7 marks) You are performing a separation experiment with gas chromatography and notice that your peaks...

  1. You are performing a separation experiment with gas chromatography and notice that your peaks have overlapping elution times. Provide three possible approaches you could take to improve the resolution of the peaks. Explain how these changes would provide a higher resolution using the resolution equation. Which of your listed approaches would be the most cost effective?

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A piece of iron (mass = 25.0g) at 95.0 C is placed in a styrofoam coffee...

A piece of iron (mass = 25.0g) at 95.0 C is placed in a styrofoam coffee cup containing 25.0 g of water at 25.0 C. If not heat is lost to the cup or surroundings, what will the final temperature of the water and iron be? The specific heat capacity of iron = 0.449 J/gC and water = 4.18 J/gC.

In: Chemistry

A 10.0 mL sample of 0.90 M HClO (Ka = 3.4. 10-8) is titrated with 0.45...

A 10.0 mL sample of 0.90 M HClO (Ka = 3.4. 10-8) is titrated with 0.45 M NaOH. What is the pH of the solution after 5.00 mL of NaOH has been added?

In: Chemistry

Please give the Correct IUPAC names of the following molecules (A)   Pt(NH3)2ClBr (B)   [Sr(H2O)8](ClO4)2 (C)   Hf(acac)4...

Please give the Correct IUPAC names of the following molecules

(A)   Pt(NH3)2ClBr

(B)   [Sr(H2O)8](ClO4)2

(C)   Hf(acac)4

(D)   Rh(H2O)3Cl3

(E)   [Co(H2O)2(NH3)2(SCN)I]Br

(F)   [Ni(en)2(NH3)4]SO4

(G) [Fe(en)3](NO2)2

(H) Na3[Co(CN)6]

(I)    Ba3[OsCl6]2

(J)   (NH4)3[MoBr6]

(K) (NMe4)2[AuCl6]

(L) (PEt4)[Ag(CN)2]

In: Chemistry

benzoic acid naphthalene and aniline Which will be eluted first in reverse chromatography

benzoic acid naphthalene and aniline

Which will be eluted first in reverse chromatography

In: Chemistry

If you started with an acetic acid solution of 2.0 mL of 0.84M Acetic acid and...

If you started with an acetic acid solution of 2.0 mL of 0.84M Acetic acid and shifted it with 0.2mL of 0.01M HCl (4 drops), what is the new pH?.

Initial pH

Final pH

Ka of acetic acid = 1.8 x 10-50.3

Start by finding the equilibrium concentrations of the acetic acid solution. Calculate the Ph based on this initial concentration (initial Ph).  

Calculate the moles of everything (compounds in the equilibrium AND the acid). Shift the equilibrium with the strong acid. Calculate the new molarities (new volume!). Now, re-establish the equilibrium and calculate the new Ph.

In: Chemistry

You measured the pH of a 0.1M HCl solution. If you had diluted this solution by...

You measured the pH of a 0.1M HCl solution. If you had diluted this solution by adding 100mL of water, what happens to the concentration of H3O+?

In: Chemistry

Procedure, Part 1: Remember when using the experimental insert to place it under a clear plastic...

Procedure, Part 1:

Remember when using the experimental insert to place it under a clear plastic reaction surface; a sheet of plastic wrap works well. Place your samples such that they straddle the “X,” with some of the material in the drop over white paper, and some over the black “X.” This will allow you to see both pale solution colors, and small amounts of lightly colored solids.

1.Obtain a page of newspaper and tear it in half from top to bottom. Examine the torn edges with the hand lens and record your observations. Now take one half and tear it in half so the second tear is perpendicular (at a right angle) to the first tear. Examine the torn edges with a hand lens and record your observations. Note any differences in the two tears.

2.Observe a large piece of rock salt with a hand lens. Note things such as its color, its approximate size and shape, and the texture of the surface. Then use a rounded rock or other hard item to gently break the large piece into a few smaller pieces (try not to completely pulverize it). Note and record what you observe. Return any large dry pieces of rock salt to the vial. Now add several drops of water to a few very small flakes of salt. Record your observations after several minutes.

3.Place a very small sample of sand over the large “X” on your reaction surface insert. Observe the sand with a hand lens. Note things such as the color, approximate size and shape of granules, and the texture of the individual grains of sand. Are they all the same, or different? If there are differences, note the different types of sand grains that you observe within the sample. Note and record what you observe. Return most of the sand to the vial. Now add several drops of water to a few grains of sand. Record your observations after several minutes.

4.Place one drop of water and one drop of mineral oil separately on your small-scale reaction surface such that they do not tough. Observe and note any differences in the behavior of the water and oil. Again look at things like size, shape, mobility, color, and luster. Examine the drops with a hand lens. Record your results.

5.Place ½ teaspoon of baking soda over the large “X” on your reaction sheet. Observe the baking soda with the hand lens and record your observations. Add one teaspoon of vinegar to the baking soda and observe the reaction. Record your observations.

Procedure

Observation

1.torn paper

                                            

                                      

Vertical tear:

Horizontal Tear:

2. Appearance of rock salt crystals

                                     

Before crushing:

After crushing:

Wet

3   Appearance of sand

                                     

                              

Dry:

Wet:

4.   oil and water on plastic

                                     

Oil:

Water:

5.   baking soda and vinegar

Baking soda, dry:

After combined:

In: Chemistry

1 a). Write down the Slater determinant for Lithium. Expand the determinant into linear combination of...

1 a). Write down the Slater determinant for Lithium. Expand the determinant into linear combination of products.

b). Write down the Slater determinant for Beryllium. Expand the determinant into linear combination of products.

In: Chemistry

Molar Mass % F- % Pure Compound in the Commercial Product NaF Sodium Fluoride 42 45...

Molar Mass

% F-

% Pure Compound in the Commercial Product

NaF

Sodium Fluoride

42

45

95

Na2SiF6

Sodium fluorosilicate

188

61

95

H2SiF6

Fluorosilicic acid

144

79

30

ii. How much 30.0% commercial fluorosilicic acid in kg must be added to 50,000 gallons of water in order to fluoridate at the optimum level?

In: Chemistry

1.00g of K3[Fe(C2O4)3] (Molar mass 437.25g/mol) Mixed with 20ml .984M sulfuric acid. TItrated with 13.4ml .028MKmNO4...

1.00g of K3[Fe(C2O4)3] (Molar mass 437.25g/mol)

Mixed with 20ml .984M sulfuric acid.

TItrated with 13.4ml .028MKmNO4

-----

What is

Moles of KMnO4 reduced?

Moles of C2O42 oxidized?

Mass of C2O42 oxidized?

Actual weight % C2O42 in KTOF3

Theoritical weight % of C2O42 in KTOF3

%Error of weight % of C2O42 in KTOF3

In: Chemistry

1. For each set of atoms/ions, write them in increasing order of size (smallest to largest)...

1. For each set of atoms/ions, write them in increasing order of size (smallest to largest) a. Mg2+, Se2- , S2- , K+ , Ca2+ b. Ga, Si, Rb, N, In c. A2+, B+ , C, D- , E2- if these elements are isoelectronic (same number of electrons) d. Put the following elements, S, Ba, Bi, Cl, Te, Ar in order of increasing ionization energy, and increasing electron affinity.

2. The following questions involve the following atoms: Ge, As, K, N, O a. Draw the Lewis symbol for each atom b. Put the atoms in order of increasing electronegativity c. If any two atoms in the above list could be paired to make a bond, which two would lead to the most polar bond?

3. Calculate the lattice energy of MgCl2: MgCl2(s)Mg2+ (g) + 2Cl- (g) given the following: The sum of the 1st and 2nd ionization energy required to make Mg2+ is 2189 kJ/mol The heat of formation of Cl(g) is 121 kJ/mol The heat of formation of MgCl2 is -641.6 kJ/mol The electron affinity of Cl(g) is -349 kJ/mol The heat of formation of Mg(g) is 147.1 kJ/mol

4. Out of the following ionic compounds LiCl, Li2O, Na2S, BeF2, Al2S3, CaS a. Put them in order of increasing bond distance between the cation/anion, lowest to highest (Li-O distance in the formula unit Li2O). Use Figure 7.8 from text. b. Put them in order of increasing (lowest to highest) lattice energy

5. Draw Lewis structures (octet rule) for the following molecules: HCN, SF3 + , CH2Cl2, ClF3, BO3 3- , CH2CCl2 (the two carbon atoms are bonded to each other), CH3OH. If a double or triple bond is required, state your reasoning as to why you came to that conclusion.

6. Two Lewis structures for BF3 are given below. Determine the formal charge for each atom (write the formal charge next to the atom) in both structures and identify the correct structure. Redraw these structures on your homework.

7. Incorrect Lewis dot structures for PCl3 and CCl2O are given below. Disregarding any resonance considerations, identify the mistakes (explicitly state the mistake) in the list of instructions that led to the drawing of these incorrect structures.

In: Chemistry

Good evening! I have synthetized benzocaine by Fischer esterification of para-aminobenzoic acid with ethanol and concentrated...

Good evening!

I have synthetized benzocaine by Fischer esterification of para-aminobenzoic acid with ethanol and concentrated H2SO4 . Product was collected by vacuum filtration and tested for melting point. Results is 79-81 while literature value is 88-90. Also Yield was 59%.

Could you please describe the way how this compound could be purified further (in detail please if it possible)

Many thanks!

In: Chemistry

A 1.05 gram sample of butter is refluxed with ethanolic KOH and required 10.4 mL of...

A 1.05 gram sample of butter is refluxed with ethanolic KOH and required 10.4 mL of 0.1875 M HCl to reach the phenolphthalein end point. If blank determination required 27.7 mL of the same standard acid, calculate the saponification value. Calculate the saponification number. Assuming butter comprised mainly of fat, what is its molar mass?

In: Chemistry