Exam 6: Thermochemistry

A sample of copper absorbs 43.6 kJ of heat,resulting in a temperature rise of 90.0°C,determine the mass (in kg)of the copper sample if the specific heat capacity of copper is 0.385 J/g°C.

Identify an energy source that is NOT renewable.

Which of the following processes is endothermic?

Wind power produces nearly ________ percent of U.S.electricity.

Describe the energy changes that occur when a book is held 6 ft off the floor and then dropped.

Identify a substance that is NOT in its standard state.

Identify a substance that is NOT in its standard state.

A piece of iron (C = 0.449 J/g°C)and a piece of gold (C = 0.128 J/g°C)have identical masses.If the iron has an initial temperature of 468 K and the gold has an initial temperature of 328 K,which of the following statements is TRUE of the outcome when the two metals are placed in contact with one another? Assume no heat is lost to the surroundings.

A 4.98 g sample of aniline (C₆H₅NH₂,molar mass = 93.13 g/mol)was combusted in a bomb calorimeter with a heat capacity of 4.25 kJ/°C.If the temperature rose from 29.5°C to 69.8°C,determine the value of ΔH°_comb for aniline.

Energy that is associated with the motion of an object is called

How much energy is required to form 141.8 g of Cl₂,according to the reaction below? The molar mass of PCl₃ is 137.32 g/mol and may be useful. 4 PCl₃(g)→ P₄(s)+ 6 Cl₂(g)ΔH°_rxn = +1207 kJ

Which statement is FALSE?

Which of the following is a standard state?

Two aqueous solutions are both at room temperature and are then mixed in a coffee cup calorimeter.The reaction causes the temperature of the resulting solution to fall below room temperature.Which of the following statements is TRUE?

How much energy is evolved during the reaction of 53.4 g of Al,according to the reaction below? Assume that there is excess Fe₂O₃. Fe₂O₃(s)+ 2 Al(s)→ Al₂O₃(s)+ 2 Fe(s)ΔH°_rxn = -852 kJ

Using the following equation for the combustion of octane,calculate the heat associated with the combustion of excess octane with 100.0 g of oxygen assuming complete combustion.The molar mass of octane is 114.33 g/mole.The molar mass of oxygen is 31.9988 g/mole. 2 C₈H₁₈ + 25 O₂ → 16 CO₂ + 18 H₂O ΔH°_rxn = -11018 kJ

Identify the greatest source of energy in the United States.

A student is preparing to perform a series of calorimetry experiments.She first wishes to determine the calorimeter constant (C_cal)for her coffee cup calorimeter.She pours a 50.0 mL sample of water at 345 K into the calorimeter containing a 50.0 mL sample of water at 298 K.She carefully records the final temperature of the water as 317 K.What is the value of C_cal for the calorimeter?

Energy that is associated with the relative positions of electrons and nuclei in atoms and molecules is called

Write the reaction illustrating ΔH°_f of CaCO₃ and draw the enthalpy diagram showing the relative positions of the reactants and products if it is an exothermic reaction.