Exam 6: Thermochemistry

According to the following thermochemical equation,what mass of H₂O (in g)must form in order to produce 975 kJ of energy? SiO₂(s)+ 4 HF(g)→ SiF₄(g)+ 2 H₂O(l)ΔH°_rxn = -184 kJ

Use the information provided to determine ΔH°_rxn for the following reaction: ΔH°_f (kJ/mol)3 Fe₂O₃(s)+ CO(g)→ 2 Fe₃O₄(s)+ CO₂(g)ΔH°_rxn = ? kJ Fe₂O₃(s)-824 Fe₃O₄(s)-1118 CO(g)-111 CO₂(g)-394

A sample of 5.23 kg of aluminum absorbs heat,which raises the temperature 50.0°C.Determine the amount of heat absorbed,in kJ,if the specific heat capacity of aluminum is 0.903 J/g°C.

Give the temperature and pressure for the standard state for a liquid.

A 6.55 g sample of aniline (C₆H₅NH₂,molar mass = 93.13 g/mol)was combusted in a bomb calorimeter with a heat capacity of 14.25 kJ/°C.If the initial temperature was 32.9°C,use the information below to determine the value of the final temperature of the calorimeter. 4 C₆H₅NH₂(l)+ 35 O₂(g)→ 24 CO₂(g)+ 14 H₂O(g)+ 4 NO₂(g) ΔH°_rxn = -1.28 × 10⁴ kJ

Identify an energy source that is not renewable.

Which of the following is true if ΔE_sys = -95 J?

Which of the following processes is endothermic?

When 50.0 mL of 0.400 M Ca(NO₃)₂ is added to 50.0 mL of 0.800 M NaF,CaF₂ precipitates,as shown in the net ionic equation below.The initial temperature of both solutions is 23.0°C.Assuming that the reaction goes to completion,and that the resulting solution has a mass of 100.00 g and a specific heat of 4.18 J/(g ∙ °C),calculate the final temperature of the solution. Ca²⁺(aq)+ 2 F^-(aq)→ CaF₂(s)ΔH° = -11.5 kJ

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

An exothermic reaction has

Explain the difference between ΔH and ΔE.

Calculate the standard enthalpy of sublimation (Δ_sub H^°)at 298K for water using the following thermochemical equations H₂O(s)= H₂O(l);Δ_fus H^° = +6.1 kJ mol^-1 H₂O(l)= H₂O(g);Δ_vap H^° = +44.0 kJ mol^-1

At constant pressure,the combustion of 15.0 g of C₂H₆(g)releases 777 kJ of heat.Calculate ΔH for the reaction given below. 2 C₂H₆(g)+ 7 O₂(g)→ 4 CO₂(g)+ 6 H₂O(l)

A block of metal initially at 70°C is submerged in water initially at 25°C in a coffee cup.Which of the following is true?

A 50.0-g sample of liquid water at 25.0°C is mixed with 29.0 g of water at 45.0°C.The final temperature of the water is ________°C.

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

Which of the following statements is true?

When 0.455 g of anthracene,C₁₄H₁₀,is combusted in a bomb calorimeter that has a water jacket containing 500.0 g of water,the temperature of the water increases by 8.63°C.Assuming that the specific heat of water is 4.18 J/(g ∙ °C),and that the heat absorption by the calorimeter is negligible,estimate the enthalpy of combustion per mole of anthracene.

Use the standard reaction enthalpies given below to determine ΔH°_rxn for the following reaction: 2 S(s)+ 3 O₂(g)→ 2SO₃(g)ΔH°_rxn = ? Given: SO₂(g)→ S(s)+ O₂(g)ΔH°_rxn = +296.8 kJ 2 SO₂(g)+ O₂(g)→ 2 SO₃(g)ΔH°_rxn = -197.8 kJ