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Bombykol, the sex pheromone secreted by the female silkworm moth,
has the formula C16H30O and the systematic name (10E,12Z)-hexadeca10,12-dien-1-ol. Draw bombykol showing correct stereochemistry for the
two double bonds
Give the structures of the major products you would obtain from reaction
of phenol with the following reagents:
(a) Br2 (1 mol) (b) Br2 (3 mol)
(c) NaOH, then CH3I (d) Na2Cr2O7, H3O+
Sodium Bicarbonate is sometimes used to neutralize acid spills. If 2.0L of 6.0M H2SO4 is spilled, how many liters of Sodium Bicarbnate, NaHCO3, is required to neutralize H2SO4?
Air-saturated water has a hydronium ion concentration caused by the dissolved CO2 of 2.0 × 10–6 M, about 20-times larger than that of pure water. Calculate the pH of the solution at 25 °C.
Coal is mostly carbon (C). When it is burned, it reacts with oxygen in the air in a combustion reaction. 43% of the electricity generated uses coal. On average, each person uses 2680 kg of coal per year to generate electricity that they use.
How much CO2 is produced?
3000 J of heat is added to a system and 2500 J of work is done by the system. What is the change in internal energy of the system.
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1. Explain;
a) Molecular absorption
(2 marks)
b) Nonradiative relaxation
(2 marks)
c) Fluorescence
Consider the cell: Zn (s) I ZnCl2 (0.0050 mol kg-1) I Hg2Cl2 (s) I Hg (I)
i) Identify the types of electrodes combined to form this cell. [2 marks]
ii) Write the overall cell reaction. [2 marks]
The standard potential of the following cell:
Cd (s) / Cd (NO3)2 (aq) // KBr (aq) / AgBr (s) / Ag (s)
Was found to be 0.4731 V at 25°C. The temperature coefficient of the emf of the cell is 1.74 x 10-4 VK-1. Write the cell reaction and calculate ΔG°, ΔS° and ΔH°. [3 marks]
Calculate the value of the mass-transfer coefficient for mass transfer from a sphere of naphthalene to air at 45 oC and 1 atm abs flowing at a velocity of 0.305 m/s. The diameter of the sphere is 25.4 mm. The diffusivity of naphthalene in air at 45 oC is 6.92 x 10-6 m2/s and the vapor pressure of solid naphthalene is 0.555 mm Hg. Viscosity of air is 1.93 x 10-5 Pa.s, density of air is 1.113 kg/m3.
