Combustion of naphthalene

Exercise 21-10 Suggest reasons why (a) the stabilization energy of biphenylene is less than twice that of benzene, and (b) the heat of combustion of naphthalene is less than that of azulene. 

In a constant-volume bomb calorimeter with a heat capacity of 13.418 kJ/K, 1.17 g of naphthalene, C10H8, is burned. Fifty-two joules of energy are required to ignite the sample. If the temperature rise of the calorimeter is 3.318 K, what is the A U and AH of combustion of naphthalene What is the AHy of naphthalene (You may assume that all water is formed in the liquid phase.)... 

The heat of combustion of naphthalene is +1234 kilocalories per mole, and of phthalic anhydride, +450 kilocalories per mole. 

In this experiment a bomb calorimeter is employed in the determination of the heat of combustion of an organic substance such as naphthalene, CioHg. The heat of combustion of naphthalene is - A/f for the reaction at constant temperature and pressure ... 

Report the individual and average values of the heat capacity C(S) and the individual and average values of the molar enthalpy change AH for the combustion of naphthalene, calculated using the average C(S). 

A quantity of 1.435 g of naphthalene (CioHg), a pungent-smeUing substance used in moth repellents, was burned in a constant-volume bomb calorimeter. Consequently, the temperature of the water rose from 20.17°C to 25.84°C. If the mass of water surrounding the calorimeter was exactly 2000 g and the heat capacity of the bomb calorimeter was 1.80 kJ/°C, calculate the heat of combustion of naphthalene on a molar basis that is, find the molar heat of combustion. 

To calculate A/f, A must be determined, which is the difference in moles of gas products and moles of gas reactants. Looking at the balanced equation for the combustion of naphthalene ... 

The heat of combustion of decahydronaphthalene (CjoHjg) is —6286 kJ/moL The heat of combustion of naphthalene (CjoHg) is —5157 kJ/moL [In both cases C02(g) and H20(l) are the products.] Using these data and data in Appendix C, calculate the heat of hydrogenation of naphthalene. Does this value provide any evidence for aromatic character in naphthalene ... 

Fownes determined the equivalent of carbon by the combustion of naphthalene (C5H2 i.e. CioHg)/ discovered a new organic base benzoline from oil of bitter almonds, which was really Laurent s hydrobenzamide, and obtained furfurol by the action of sulphuric acid on bran and prepared a vegetable alkali (furfuramide) by the action of ammonia on it. Fownes mentions that furfurol had been noticed and named by William Coley Jones. Jones says upon distilling the lignin of wheat in a manner which I shall describe (but does not) he obtained a liquid of s.g. i-iyS-i iSy, b.p. 208 F., many chemical reactions of which he describes in detail. He says I have named the body furfurol torn furfur bran and oleum oil, being a peculiar essential oil produced from that body, either as an educt or product. He found that it is inflammable. Furfurol (kiinstliches Ameisenol, artificial oil of ants) had been discovered by Dobereiner (seep. 179). 

The combustion of naphthalene (CioEls), which releases 5150.1 kj/mol, is often used to calibrate calorimeters. A 1.05-g sample of naphthalene is burned in a calorimeter, producing a temperature rise of 3.86°C. Burning a 1.83-g sample of coal in the same calorimeter causes a temperature change of 4.90°C. What is the energy density of the coal ... 

A 1.620 g sample of naphthalene, CioHg(s), is completely burned in a bomb calorimeter assembly and a temperature increase of 8.44 °C is noted. If the heat of combustion of naphthalene is -5156 kj/mol CioHg, what is the heat capacity of the bomb calorimeter ... 

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