3. Consider the 4 reaction-energy diagrams shown here. (a) Which diagram(s) represent reaction(s) were the reactants and products are equal in energy? (b) Which diagram(s) represent reaction(s) with an intermediate? (c) Which diagram represents the slowest reaction? Potential energy Potential energy Reaction coordinate Reaction coordinate Potential energy Potential energy Reaction coordinate D Reaction coordinate (a) (b)

How much heat is released when a mixture containing 10.0 g CS2 and 10.0 g Cl2 reacts by the following equation? CS2(g)+3Cl2(g)S2Cl2(g)+CCl4(g);H=230kJ

Combustion of table sugar produces CO2(g) and H2O( l). When 1.46 g table sugar is combusted in a constant-volume (bomb) calorimeter, 24.00 kJ of heat is liberated. a. Assuming that table sugar is pure sucrose, C12H22O11 (s), write the balanced equation for the combustion reaction. b. Calculate E in kJ/mol C12H22O11 for the combustion reaction of sucrose.

A rebreathing gas mask contains potassium superoxide, KO2, which reacts with moisture in the breath to give oxygen. 4KO2(s)+2H2O(l)4KOH(s)+3O2(g) Estimate the grams of potassium superoxide required to supply a persons oxygen needs for one hour. Assume a person requires 1.00 102 kcal of energy for this time period. Further assume that this energy can be equated to the heat of combustion of a quantity of glucose, C6H12O6, to CO2(g) and H2O(l). From the amount of glucose required to give 1.00 102 kcal of heat, calculate the amount of oxygen consumed and hence the amount of KO2 required. The ff0 for glucose(s) is 1273 kJ/mol.

9.61 Silane, SiH4, burns according to the reaction, SiH4+2O2SiO2+2H2O , with H=1429 kJ. How much energy is released if 15.7 g of silane is burned?

Describe the interconversions of potential and kinetic energy in a moving pendulum. A moving pendulum eventually comes to rest. Has the energy been lost? If not, what has happened to it?

How much would the temperature of 275 g of water increase if 36.5 U of heat were added?

A small car is traveling at twice the speed of a larger car, which has twice the mass of the smaller car. Which car has the greater kinetic energy? (Or do they both have the same kinetic energy?)

Hypothetical elements A2 and B2 react according to the following equation, forming the compound AB. A2(aq)+B2(aq)2AB(aq);H=+271kJ/mol If solutions A2(aq) and B2(aq), starting at the same temperature, are mixed in a coffee-cup calorimeter, the reaction that occurs is a exothermic, and the temperature of the resulting solution rises. b endothermic, and the temperature of the resulting solution rises. c endothermic, and the temperature of the resulting solution falls. d exothermic, and the temperature of the resulting solution falls. e exothermic or endothermic, depending on the original and final temperatures.

9.31 A metal radiator is made from 26.0 kg of iron. The specific heat of iron is 0.449Jg1C1 . How much heat must be supplied to the radiator to raise its temperature from 25.0 to 5 5.0°C?