Exam 6: Thermochemistry

A 6.50-g sample of copper metal at 25.0°C is heated by the addition of 84.0 J of energy.The final temperature of the copper is ________°C.The specific heat capacity of copper is 0.38 J/g ∙ K.

Choose the reaction that illustrates ΔH°_f for Ca(NO₃)₂.

Which of the following statements are false?

When 1 mole of butane burns at constant pressure and 100^°C,it produces 2658 kJ of heat and does 5 kJ of work.What are the values of ΔE and q for the combustion of 1 mole of butane?

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.

Given w = 0,an endothermic reaction has the following.

Use the information provided to determine ΔH°_rxn for the following reaction: ΔH°_f (kJ/mol)CH₄(g)+ 3 Cl₂(g)→ CHCl₃(l)+ 3 HCl(g)ΔH°_rxn = ? CH₄(g)-75 CHCl₃(l)-134 HCl(g)-92

Calculate the change in internal energy (ΔE)for a system that is giving off 25.0 kJ of heat and is changing from 12.00 L to 6.00 L in volume at 1.50 atm pressure.(Remember that 101.3 J = 1 L^∙atm)

Use the information provided to determine ΔH°_rxn for the following reaction: ΔH°_f (kJ/mol)CH₄(g)+ 4 Cl₂(g)→ CCl₄(g)+ 4 HCl(g)ΔH°_rxn = ? CH₄(g)-75 CCl₄(g)-96 HCl(g)-92

Match the following. --q

Which of the following processes is exothermic?

Calculate the amount of heat (in kJ)required to raise the temperature of a 79.0 g sample of ethanol from 298.0 K to 385.0 K.The specific heat capacity of ethanol is 2.42 J/g°C.

Hydrogen peroxide decomposes to water and oxygen at constant pressure by the following reaction: 2H₂O₂(l)→ 2H₂O(l)+ O₂(g)ΔH = -196 kJ Calculate the value of q (kJ)in this exothermic reaction when 4.00 g of hydrogen peroxide decomposes at constant pressure?

Which of the following signs on q and w represent a system that is doing work on the surroundings,as well as losing heat to the surroundings?

Use the ΔH°_f and ΔH°_rxn information provided to calculate ΔH°_f for IF: ΔH°_{f (kJ/mol)} IF₇(g)+ I₂(g)→ IF₅(g)+ 2 IF(g)ΔH°_rxn = -89 kJ IF₇(g)-941 IF₅(g)-840

A 21.8 g sample of ethanol (C₂H₅OH)is burned in a bomb calorimeter,according to the following reaction.If the temperature rises from 25.0 to 62.3°C,determine the heat capacity of the calorimeter.The molar mass of ethanol is 46.07 g/mol. C₂H₅OH(l)+ 3 O₂(g)→ 2 CO₂(g)+ 3 H₂O(g)ΔH°_rxn = -1235 kJ

For ?E_sys to always be -,what must be true?

A 12.8 g sample of ethanol (C₂H₅OH)is burned in a bomb calorimeter with a heat capacity of 5.65 kJ/°C.Using the information below,determine the final temperature of the calorimeter if the initial temperature is 25.0°C.The molar mass of ethanol is 46.07 g/mol. C₂H₅OH(l)+ 3 O₂(g)→ 2 CO₂(g)+ 3 H₂O(g)ΔH°_rxn = -1235 kJ

Calculate the kinetic energy of a 150 g baseball moving at a speed of 39.m/s (87 mph).

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.When 0.025 mol of Na is added to 100.00 g of water,the temperature of the resulting solution rises from 25.00°C to 35.75°C.If the specific heat of the solution is 4.18 J/(g ∙ °C),calculate ΔH for the reaction,as written. 2 Na(s)+ 2 H₂O(l)→ 2 NaOH(aq)+ H₂(g)ΔH= ?