Exam 10: Thermochemistry

Calculate the change in internal energy (ΔE)for a system that is giving off 25.0 kJ of heat and is changing from 18.00 L to 15.00 L in volume at 1.50 atm pressure.(Remember that 101.3 J = 1 L^∙atm)

Define specific heat capacity.

Calculate the change in internal energy (ΔE)for a system that is absorbing 35.8 kJ of heat and is expanding from 8.00 to 24.0 L in volume at 1.00 atm.(Remember that 101.3 J = 1 L^∙atm)

Calculate the change internal energy (ΔE)for a system that is giving off 65.0 kJ of heat and is performing 855 J of work on the surroundings.

The specific heat of copper is 0.385 J/(g ∙ °C).If 34.2 g of copper,initially at 24.0°C,absorbs 4.689 kJ,what will be the final temperature of the copper?

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

How much energy is evolved during the formation of 197 g of Fe,according to the reaction below? Fe₂O₃(s)+ 2 Al(s)→ Al₂O₃(s)+ 2 Fe(s)ΔH°_rxn = -852 kJ

Define chemical energy.

For a particular process that is carried out at constant pressure,q = 145 kJ and w = -35 kJ.Therefore

A piece of iron (mass = 25.0 g)at 398 K is placed in a styrofoam coffee cup containing 25.0 mL of water at 298 K.Assuming that no heat is lost to the cup or the surroundings,what will the final temperature of the water be? The specific heat capacity of iron = 0.449 J/g°C and water = 4.18 J/g°C.

Which of the following substances (with specific heat capacity provided)would show the greatest temperature change upon absorbing 100.0 J of heat?

Explain the difference between ΔH and DE.

A sample of copper absorbs 43.6 kJ of heat,resulting in a temperature rise of 40.0°C,determine the mass (in kg)of the copper sample if the specific heat capacity of copper is 0.385 J/g°C.

Use the standard reaction enthalpies given below to determine ΔH°_rxn for the following reaction 2 S(s)+ 3 O₂(g)→ 2 SO₃(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

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)

Choose the reaction that illustrates ΔH°_f for CsHCO₃.

How much heat energy is required to raise the temperature of 0.298 mole of water from 35.93°C to 79.84°C? The specific heat capacity of water = 4.18 J/g°C.

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.

Give the units of specific heat capacity.

Sodium metal reacts with water to produce hydrogen gas and sodium hydroxide according to the chemical equation shown below.When 0.0 25 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 = ?