Question

1) Which of the following statements is/are CORRECT?
1. Naturally occurring isotopes account for only a small fraction of known radioactive isotopes.
2. A few radioactive isotopes with long half-lives, such as U-235 and U-238, are found in nature.
3. Trace quantities of some short-lived radioactive isotopes, such as C-14, are found in nature because they are formed continuously by nuclear reactions.
a. 1 only
b. 2 only
c. 3 only
d. 1 and 2
e. 1, 2, and 3

Answer A


2) Ions such as [Co(H2O)6]3+ and [Ag(CN)2]– are called ____.
a. ligands
b. Lewis bases
c. chelates
d. alloys
e. coordination complexes

Answer E



3) All of the following molecules or ions can act as polydentate ligands EXCEPT ____.
a. phenanthroline; C12H8N2
b. acetylacetate ion; CH3COCHCOCH3–
c. oxalate ion; C2O42–
d. ethylenediamine; H2NCH2CH2NH2
e. dimethylamine; (CH3)2NH2

Answer E

4) What is the coordination number of the central metal ion in [Cr(en)2(OH)2]NO3? (en = H2NCH2CH2NH2)
a. 0
b. 2
c. 4
d. 6
e. 7

Answer D

5) What is the name of the compound having the formula [Cr(en)2(H2O)2]SO4?

a. dihydroxydiethlyenediamminechromate(... sulfate
b. diaquabis(ethylenediamine)sulfatochr...
c. bis(ethylenediamine)diaquachromium(I... sulfato
d. diaquabis(ethylenediamine)sulfatochr...
e. diaquabis(ethylenediamine)chromium(I... sulfate

Answer E

Answer 1

I disagree with 1.
I agree with 2,3,4.
I con't see all of the name typed on 5 but e is right if that is chromium IV.