How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Scott Your Own Question

Scott, MIT Graduate
Category: Homework
Satisfied Customers: 3040
Experience:  MIT Graduate (Math, Programming, Science, and Music)
Type Your Homework Question Here...
Scott is online now
A new question is answered every 9 seconds

Hydrocarbons contain only hydrogen and carbon. Which of the

Customer Question

Hydrocarbons contain only hydrogen and carbon. Which of the following is not a class of pure hydrocarbons?
a. alkynes
b. alcohols
c. alkenes
d. alkanes

2. What prefix is used to name a hydrocarbon with two carbon atoms?
a. Dec-
b. Eth-
c. Prop-
d. Hex-

3. You have two neutral solutions. One contains the indicator methyl red, which turns red in strongly acidic aqueous solutions but is otherwise yellow. The other contains the indicator phenol red, which turns red in strongly basic aqueous solutions but is otherwise yellow. Which of these steps would cause a color change in both solutions?
a. Add a weak acid to both solutions.
b. Add a strong acid to both solutions.
c. Add a strong acid to one solution, and a strong base to the other.
d. Add a weak acid to one solution, and a weak base to the other.

4. Which of the following shows a correctly balanced reaction in which cerium is reduced?
a. Ce3+ (aq) + Fe2+ (aq) -->
          Ce4+ (aq) + Fe3+ (aq)
b. Ce4+ (aq) + Fe2+ (aq) -->
          Ce3+ (aq) + Fe3+ (aq)
c. Ce3+ (aq) + Fe3+ (aq) -->
          Ce4+ (aq) + Fe2+ (aq)
d. Ce4+ (aq) + Fe3+ (aq) -->
          Ce3+ (aq) + Fe2+ (aq)

5. Suppose that the gas in a storage tank exerts a pressure of 55.125 lb/in2 . What is the pressure of the gas in units of torr?
a. 3.75 torr
b. 3.799 torr
c. 41,895 torr
d. 2850.0 torr

6. In a manometer the mercury level at the open ed of the tube is 215 mm higher than at the closed end of the tube. If the atmospheric pressure is 1 atm, what is the pressure of the gas sample in units of torr?
a. 1.28 torr
b. 545 torr
c. 975 torr
d. 215 torr

7. Using Boyle's Law, predict what will happen to the pressure of a gas in a container at constant temperature, if the volume of the container is changed to one-half its original size.
a. Nothing will happen to the pressure.
b. The pressure will be decrease to one-half its original value.
c. The pressure will increase to twice its original value.
d. More information is needed.

8. A sample of gas is heated. During the heating process, the volume of the gas increases 1.7 times. If the initial temperature of the gas is 80°C, what is the final temperature of the gas?
a. 136°C
b. 600 K
c. 210 K
d. 353 K

9. Suppose that you have a 2.0 L sample of hydrogen at 1.00 atm and 59°C. If you heat the sample to 84°C and it expands to a volume of 3.7 L, what will the final pressure be?
a. 0.58 atm
b. 0.76 atm
c. 0.54 atm
d. 1.00 atm

10. A helium balloon with a volume of 2.4 L contains 0.10 moles of gas at 25°C and 1 atm of pressure. The balloon leaks 0.02 moles of gas until someone manages to seal the hole. What is the new volume of the balloon?
a. 3.0 L
b. 0.5 L
c. 19.2 L
d. 2 L

11. There is an unlabeled gas cylinder in the chemistry lab. The cylinder contains a gaseous compound. A sample of the compound shows that it contains 27.27% carbon and 72.73% oxygen. The 1.50 L bottle was found at STP and contained 2.94 g of the compound. Identify the number of moles of the compound in the bottle.
a. 1.96 mol
b. 0.0669 mol
c. 0.105 mol
d. 0.0609 mol

12. Two gas tanks are linked by a connecting tube of negligible volume with a valve. One contains 15 L of nitrogen at 7.2 atm of pressure. The other contains 8.3 L of helium at 4.1 atm of pressure. If the valve is opened, what is the final pressure of the two tanks combined?
a. 142 atm
b. 4.5 atm
c. 6.1 atm
d. 0.48 atm

13. Which of the following steps illustrates work being done?
a. A beaker of water being heated from 25°C to 75°C.
b. A battery producing 1.5 V.
c. A box being pushed up a ramp.
d. A log burning in a fireplace.

14. Which of the following has the highest number of Calories?
a. 7.2 g of fat
b. 9.8 g of starch
c. 15.5 g of sugar
d. 14.3 g protein

15. What is the sign of q when heat moves from the surroundings to the system?
a. It depends on the value of work.
b. Positive
c. Negative
d. This situation never occurs.

16. Which of the following is true about an endothermic reaction?
a. The reactants have a lower enthalpy than the products.
b. The reactants have a higher enthalpy than the products.
c. The reactants have the same enthalpy as the products.

17. For the reaction:

6HCl(aq) + 2Fe(s) --> 2FeCl3(aq) + 3H2(g)

Which of the following rate expressions is NOT correct?
a. Rate = - [HCl]/6 t
b. Rate = - [Fe]/2 t
c. Rate = 2 [FeCl3]/ t
d. Rate = [H2]/3 t

18. The rate equation for the synthesis of water

2H2 + O2 --> 2H2O


Rate = k[H2][O2]

What is the overall order of this reaction?
a. 0
b. 1
c. 2
d. 3

19. The following reaction is second order in [A] and second order overall.

2A --> B + C

The instantaneous rate of reaction is 1.8 × 10–3 M/s when [A] is equal to 0.63 M. What is the rate constant, k, of this reaction?
a. 1.4 × 10–3 M–1s–1
b. 2.2 × 102 M–1s–1
c. 4.5 × 10–3 M–1s–1
d. 7.1 × 10–4 M–1s–1

20. The activation energy (Ea) on a reaction diagram for an uncatalyzed reaction is generally ________ a catalyzed reaction.
a. the same as
b. unrelated to
c. greater than
d. less than

21. In a reaction, the equilibrium constant for the forward reaction is Kf and the equilibrium constant of the backward reaction is Kb. What is the relationship between Kf and Kb?
a. Kf = Kb
b. Kb = 1 + Kf
c. Kf = 1/Kb

a. 0.95
b. 1.05
c. 0.2
d. 3.74

a. The energy of the system will increase.
b. More methanol will decompose.
c. The equilibrium position will not be affected.
d. More methanol will be formed.

25. What is the [H3O+] in a solution with a pH of 2.34?
a. 4.57 x 10–3 M
b. 4.6 x 10–3 M
c. 4.57 x 103 M
d. 4.6 x 103 M

26. A 0.200 M solution of a weak acid, HA, is 9.4% ionized. Using this information, calculate Ka for HA.
a. 1.8 x 10–3
b. 3.8 x 10–3
c. 9.4 x 10–3
d. 1.9 x 10–2

27. Which of the following is not a buffer solution?
a. a weak acid (to neutralize a strong base) and its conjugate base (to neutralize a strong acid)
b. a weak base (to neutralize a strong acid) and its conjugate acid (to neutralize a strong base)
c. a strong acid (to neutralize a strong base) and its conjugate base (to neutralize a strong acid)
d. formic acid and sodium formate

28. Which statement about alcohols is not correct?
a. Alcohols contain hydroxyl functional groups.
b. Alcohols are organic molecules.
c. Alcohols contain nitrogen.
d. Alcohols are named by their Greek prefix
+ -anol.

29. Which of the following shows the alkanes in correct order from lowest to highest boiling points?
a. hexane, pentane, butane, propane, ethane, methane
b. hexane, ethane, propane, butane, pentane, methane
c. methane, ethane, propane, butane, pentane, hexane
d. methane, ethane, propane, pentane, butane, hexane

30. Which characteristic defines the main difference between a basic buffer system and an acidic buffer system?
a. A basic buffer system uses more base than acid per liter.
b. A basic buffer system is a solution that can maintain an acidic pH when more acid or                   base is added.
c. A basic buffer system maintains a steady basic pH regardless of how much acid or base is added.
d. A basic buffer system is a solution that can maintain a basic pH when more acid or base is added.
Submitted: 4 years ago.
Category: Homework
Expert:  R.R. Jha replied 4 years ago.
Hi streetcream,
Can you please complete question no. 22 and 23 ?

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
< Last | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C. Freshfield, Liverpool, UK
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex Los Angeles, CA
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP Hesperia, CA
  • I couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin Kernersville, NC
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther Woodstock, NY
  • Thank you so much for taking your time and knowledge to support my concerns. Not only did you answer my questions, you even took it a step further with replying with more pertinent information I needed to know. Robin Elkton, Maryland
  • He answered my question promptly and gave me accurate, detailed information. If all of your experts are half as good, you have a great thing going here. Diane Dallas, TX

Meet The Experts:

  • Manal Elkhoshkhany


    Satisfied Customers:

    More than 5000 online tutoring sessions.
< Last | Next >
  • Manal Elkhoshkhany's Avatar

    Manal Elkhoshkhany


    Satisfied Customers:

    More than 5000 online tutoring sessions.
  • Linda_us's Avatar


    Finance, Accounts & Homework Tutor

    Satisfied Customers:

    Post Graduate Diploma in Management (MBA)
  • LogicPro's Avatar



    Satisfied Customers:

    Expert in Java C++ C C# VB Javascript Design SQL HTML
  • Lani S.'s Avatar

    Lani S.


    Satisfied Customers:

    Registered Nurse, Internet Researcher, Private Tutor
  • Chris M.'s Avatar

    Chris M.

    M.S.W. Social Work

    Satisfied Customers:

    Master's Degree, strong math and writing skills, experience in one-on-one tutoring (college English)
  • F. Naz's Avatar

    F. Naz

    Chartered Accountant

    Satisfied Customers:

    Experience with chartered accountancy
  • Bizhelp's Avatar



    Satisfied Customers:

    Bachelors Degree and CPA with Accounting work experience