Dimethylhydrazine is a carbon-hydrogen-nitrogen compound used in rocket fuels. When burned completely, a 0.312 g sample yields 0.458 g CO2 and 0.374 g H2O. What is the empirical formula of diemthylhydrazine?
In: Chemistry
Write equations for the reaction of each substance in oxygen if a reaction occurs:
1. Adding glowing orange wooden splint to oxygen and it relighting.
2. Adding glowing orange steel wool to oxygen and it sparkling.
3. Adding glowing orange charcoal to oxygen and relit
4. Adding burnt sulfur to oxygen and it relighting with blue flame
In: Chemistry
1)
Which of the following compounds exhibits optical isomerism?
Which of the following compounds exhibits optical isomerism?
| CH3-CHBr-CH3 | |||||||||||||||||||||
| CH3-CH2-CHF-CH3 | |||||||||||||||||||||
| CH3-CH2-CH3 | |||||||||||||||||||||
| CH3-CH2-CH2F | |||||||||||||||||||||
|
CH3-CH2-CBr2-CH3 2) Based on the molecular formula, determine whether each compound is an alkane, alkene, or alkyne. (Assume that the hydrocarbons are noncyclical and there is no more than one multiple bond.) Drag the appropriate items to their respective bins. "C3H6 C4H10 C4H6 C2H2" Alkane Alkene Alkyne 3) Which of the following alkane names is correct? Which of the following alkane names is correct?
|
5)
Write the balanced chemical equation for the catalytic hydrogenation (addition of H2) to CH3CH=CHCH3.
Write the balanced chemical equation for the catalytic hydrogenation (addition of H2) to CH3CH=CHCH3.
| CH3CH=CHCH3 + H2 → CH3CH2CH2CH3 | |
| CH3CH=CHCH3 + 2 H2 → 2 CH3CH3 | |
| CH3CH=CHCH3 + 3 H2 → CH3CH3 + 2 CH4 | |
| CH3CH=CHCH3 + 2 H2 → CH3CH2CH3 + CH4 | |
|
CH3CH=CHCH3 + 4 H2 → 4 CH4 |
6)
Write the balanced chemical equation for the addition of HBr to CH2=CHCH2CH3.
Write the balanced chemical equation for the addition of HBr to CH2=CHCH2CH3.
| CH2=CHCH2CH3 + 2 HBr → CH3Br + CH2BrCH2CH3 | |
| CH2=CHCH2CH3 + HBr → CH3CHBrCH2CH3 | |
| CH2=CHCH2CH3 + 4 HBr → 4 CH3Br | |
| CH2=CHCH2CH3 + 2 HBr → 2 CH2BrCH3 | |
8)
Which of the following names is correct?
Which of the following names is correct?
| 1,2,4-trifluorobenzene | |
| 2,5-dibromocyclohexene | |
| 4-isopropyl-6-methylbenzene | |
| 1,3,4-fluorobenzene | |
| 1-methyl-3-isopropylhexene |
In: Chemistry
Write the dissociation reaction for the following acids in water. Use the appropriate arrow symbols. Label the acid, base , conjugate acid and conjugate base for each:
HCl(hydrochloic acid)
C6H6COOH (benzoic acid)
In: Chemistry
In: Chemistry
What is the pH at the equivalence point in the titration of a 23.0 mL sample of a 0.304 M aqueous hydrocyanic acid solution with a 0.433 M aqueous sodium hydroxide solution?
pH =
A 30.6 mL sample of a 0.393 M aqueous acetic acid solution is titrated with a 0.296 M aqueous potassium hydroxide solution. What is the pH after 16.7 mL of base have been added?
pH =
When a 18.0 mL sample of a 0.476 M aqueous acetic acid solution is titrated with a 0.320 M aqueous potassium hydroxide solution, what is the pH after 40.2 mL of potassium hydroxide have been added?
pH =
In: Chemistry
A 1 liter solution contains 0.436 M hypochlorous acid and 0.581 M sodium hypochlorite.
Addition of 0.109 moles of barium hydroxide will:
(Assume that the volume does not change upon the addition of barium hydroxide.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
A 1 liter solution contains 0.460 M hydrofluoric acid and 0.345 M potassium fluoride.
Addition of 0.380 moles of hydrobromic acid will:
(Assume that the volume does not change upon the addition of hydrobromic acid.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
A 1 liter solution contains 0.401 M hydrofluoric acid and 0.301 M potassium fluoride.
Addition of 0.150 moles of hydrobromic acid will:
(Assume that the volume does not change upon the addition of hydrobromic acid.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
In: Chemistry
How many grams of NaOH (MW = 40.0) are there in 500.0 mL of a 0.175 M NaOH solution?
In: Chemistry
1. While synthesizing aspirin, a student masses out 3.4898 g salicylic acid.
A) What is the theoretical yield of aspirin the student can make? (the molar mass of salicylic acid is 138.12 g/mol and molar mass of aspirin is 180.2 g/mol)
B) After vacuum filtration, the student collects 3.8929 g aspirin. What is the percent yield?
C) What is the percent error?
2. What is the yield of aspirin when reacting excess salicylic acid with 2.09 mL of acetic anhydride? The density of acetic anhydride is 1.082 g/mL.
3. What is the percent yield if you prepared 2.80 x 10 3 g of aspirin from an industrial process when the theoretical yield was 3.87 kg?
4. A) Explain how the FeCl3 test helps you determine the purity of aspirin (What functional group causes the reaction)?
B) After reviewing the results of the FeCl3 test that your lab instructors posted, what is the purest aspirin product, the commercial aspirin or the synthesized aspirin? Why?
C) Propose a reason for your observation for part B.
D) What was the purpose of testing ethanol with FeCl3?
5. A) What functional group(s) is/are responsible for the acidity of aspirin?
B) According to the pH test results posted by your instructors, what is the sample that is most acidic? And why?
C) Why do you propose that we convert Salicylic acid to Acetylsalicylic acid although they both function as analgesics?
In: Chemistry
Consider the transfer of methane from benzene to water. What temperature would be needed to make this process spontaneous? Also discuss the implications of this when considering hydrophobic interactions.
In: Chemistry
Which of the following aqueous solutions are good buffer systems?
0.13 M calcium hydroxide + 0.25 M calcium bromide
0.27 M ammonia + 0.32 M potassium hydroxide
0.39 M sodium chloride + 0.28 M barium chloride
0.28 M hydrobromic acid + 0.16 M potassium bromide
0.21 M hydrocyanic acid + 0.22 M potassium cyanide
0.34 M nitrous acid + 0.21 M sodium nitrite
0.16 M sodium fluoride + 0.21 M hydrofluoric acid
0.28 M ammonium nitrate + 0.39 M ammonia
0.21 M acetic acid + 0.13 M potassium acetate
0.29 M perchloric acid + 0.24 M potassium perchlorate
In: Chemistry
In: Chemistry
Discuss capillary (zone) electrophoresis, micellar electrokinetic chromatography (MEKC) and capillary electrochromatography. Describe similarities and differences in working principle, injection, and separation. Discuss advantages and disadvantages of each of these techniques. Which compounds would you separate with each of these techniques?
In: Chemistry
1)Describe IN POINT FORM what happens when you raise the pressure of a sample of water from 0.004 atm to 40 atm at a constant temperature of 100 degrees celcius.
2)Describe IN POINT FORM what happens when you raise the temperature of a sample of water from -100 to +300 at a constant pressure of 40 atm.
In: Chemistry
From the data below, calculate the total heat (in J) needed to convert 0.535 mol of gaseous ethanol at 300.0°C and 1 atm to liquid ethanol at 25.0°C and 1 atm:
b.p. at 1 atm: 78.5°C
ΔH o vap : 40.5 kJ/mol
cgas: 1.43 J/g·°C
cliquid: 2.45 J/g·°C
______J
In: Chemistry