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Cinnamaldehyde is a molecule responsible for the aroma and flavor of cinnamon. Guaiacol is a molecule that gives a smoky flavor to salmon and coffee; it is also a pheromone that causes locust to swarm.  Choose the structure that best matches the IR spectra below:  

[1] bond strength increases the stretching frequency, which means higher infrared energy is absorbed.

An electron enters a magnetic field of 0.75 T with a velocity perpendicular to the direction of the field. At what frequency does the electron traverse a circular path?

A circular coil of radius 5.0 cm and resistance 0.20 Ω is placed in a uniform magnetic field perpendicular to the plane of the coil. The magnitude of the field changes with time according to B(t)=(0.50 T)e−20t,{“version”:”1.1″,”math”:”B(t) = (0.50~\text{T}) e^{ -20t},”} where t is in seconds. What is the magnitude of the current induced in the coil at the time t = 2.0 s?

   dg = 2l + 1  ;  nodes = n – l – 1         NA = 6.022 x 1023    

Three particles travel through a region of space where the magnetic field is out of the page, as shown in the figure. The electric charge of each of the three particles is, respectively,  

a.  In your own words, explain the physical meaning of enthalpy. Is the change in enthalpy for a reaction an extensive (mass-dependent)       property? Explain your answer. b. Explain how the value of ΔH for a reaction change upon:           i) multiplying the reaction by an integer factor.         ii) reversing the reaction.         iii) Why do these relationships hold? c. What is Hess’s law and why is it useful?          

Use the following table to answer the problems focused on the determination of oxidation numbers. Rules Operational considerations 1 The oxidation number of an atom in an elemental substance is zero. 2 The oxidation number of a monatomic ion is equal to the ion’s charge. 3 Oxidation number for common elements H, O , and halogens:H: +1 when combined with nonmetals; −1 when combined with metals.O: −2 in most compounds; Sometimes −1 (so-called peroxides, O22−); Very rarely − ½ (so-called superoxides, O2−); Positive values when combined with F (values vary).Halogens: −1 for F always; −1 for other halogens except when combined with oxygen or other halogens (positive oxidation numbers in these cases, varying values). 4 The sum of the oxidation numbers for all atoms in a molecule or polyatomic ion equals the charge on the molecule or ion. Determine the oxidation state of N in NO3-

If an electron travels at a velocity of 2.000 × 107 m s–1 and has a mass of 9.109 × 10–28 g, what is its wavelength?