Cinnamaldehyde is a molecule responsible for the aroma and f…
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:
Read DetailsA circular coil of radius 5.0 cm and resistance 0.20 Ω is pl…
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?
Read Detailsa. In your own words, explain the physical meaning of entha…
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?
Read DetailsUse the following table to answer the problems focused on th…
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-
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