Elemental Analysis Results:  C(74.09%) H(7.11%) O(18.80%). The following mas spectra belong to this compound. Please annotate the mass spectra. Thanks!

6. The precise mass of a compound was determined by high resolution mass spec to be 84.0575. Using the values in the precise atomic mass table below determine which molecular formula best agrees with this mass – C6H12, CsH:O or C4H&N2? Table 13.3 The Exact Masses of Some Common Isotopes Mass Isotope Mass Isotope 31.9721 amu 1.007825 amu 325 34.9689 amu 35CI 12C 12.00000 amu 78.9183 amu 19B. 14N 14.0031 amu 15.9949 amu 160 O 2011 Pearson Education, inc.

e) when a compound Containy e, H and 2 N's . Now, when we add two nitrogen atom we Should 2 CH2 unit (a). when a Compound Contaiy only c and H. thet meany C2 Hq urit mupt be elimate from the base formula, 136 = 10 +음 Nou, the mew formula Containing two nitrogen is - Accurding to the formula n=10 and r: 6 the base formula mupt be- Go HiD46 Ov, Cro Hia (d) when a Compound Containg c, H, 2NS and 20's when a Compound Contains e , H and 2 o's . Now, when we add two nitrogen and two orygen atom , we 2 CH4 and 2CH2 unit respectively, ) Now, when wse add two onygen atom Should elimimate 2 CHq unit that meanp G Hg unit myst eliminate from the hase formula. we Should that means we should elimimete C4 H2 unit from the base for mula . Now, the new formula Containig two onygen atom in Now, the new for mula Containing tawo nitrogen and two ozygen sn Cc HA Oz N2 6. Calculate the molecular formulas for possible compounds with molecular mass 136 using the Rule of 13. a. a compound that contains only C…

2.Calculate the molecular weight of sulfur by using m, W1and W2 3.The atomic weight of sulfur is 32 g/mol. By using the result from (2), write the molecular formula of sulfur as Sn. What is n?

a A b с Prelab Question #7 Homework Unanswered e f B d D C Strength of response E 0 F A With respect to Figure 3, which signal would you expect to represent the compound with the highest boiling point? 2.0 Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. B C 4.0 D 6.0 8.0 10.0 Time (min) Figure 3. An example gas chromatograph. E F 12.0 14.0 16.0 ✰

3

The mass spectrum of a sample of an element is shown. What is the Ar of the element ?

Hi, I am working on a homeowrk problem and I can't figure out how to approach it.  How would I go about finding the mass of a sample of a compound when given how many atoms there are of a certain element? i.e mass of CO2 (subscript 2) when given it contains a certain number of oxygen atoms.

An unknown compound contains 42.6 oxygen, 32% carbon, 18.7% N and the remainder is hydrogen. Using mass spectroscopy its molar mass was determined to be 75.0g/mol. What is the molecular formula of the compound.

40. Deuterium oxide, D20, is water that contains the stable hydrogen isotope H, usually shown as D. When dissolved in deuterium oxide, ethanol undergoes the following reaction: CH3CH2OH + D2O → CH3CH2OD + HOD What is the best way of showing that this reaction has occurred? A. By testing the product with phosphorus pentachloride and not getting steamy fumes. B. By determining the mass spectrum of the mixture and showing peaks at m/z values of 20 and 46. C. By fractionally distilling the mixture and determining the amount of CH3CH2OD using a Geiger counter. D. By determining the mass spectrum of the mixture and showing peaks at m/z values by 19 and 47.