{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

practiceexam21

# practiceexam21 - City College Chemistry Department...

This preview shows pages 1–3. Sign up to view the full content.

City College, Chemistry Department Chemistry 10301, sections T, T2, Τ 3 Prof. T. Lazaridis Second Midterm exam, Oct 29, 2009 Last Name: _____________________________________________ First Name: _____________________________________________ SSN l ast 4 : ______________________________________________ Note: There are 7 questions in this exam (check both sides of the sheet). Fill in your answer in the blank space provided immediately following each question. 1/2 point will be subtracted every time you report a numerical result with an incorrect number of significant figures. The last 3 sheets of this exam contains information that may or may not be needed to answer these questions. SHOW WORK! 1. (18) a. (6) What volume of a 0.2000 M K 2 Cr 2 O 7 solution do we need in order to prepare 100 mL of 0.0400 M K 2 Cr 2 O 7 solution? McVc = Md Vd => Vc = (0.0400 M X 100mL) / 0.2000 M = 20 mL b. (6) We have a sample of gas at 285 o C. To what Celsius temperature must the gas be heated to double its pressure if there is no change in the volume of the gas? Ti= 285 + 273 = 558 K Pf = 2 Pi PiV = nRTi => Ti/Tf = Pi/Pf= ½ => Tf = 2 Ti = 1116K , or 843 o C Pf V= nRTf c. (6) Assign oxidation numbers to N in each of the following compounds: N 2 : 0 ΝΟ 2 : +4 N 2 O 3 : +3 HNO 2 : +3 N 2 H 4 : -2 NH 3 : -3

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2.
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern