Skip to main content
Pearson+ LogoPearson+ Logo
Ch.18 - Free Energy and Thermodynamics
All textbooksTro 4th EditionCh.18 - Free Energy and ThermodynamicsProblem 34
Previous problem
Next problem
Chapter 18, Problem 34

Calculate the change in entropy that occurs in the system when 55.0 g of water vaporizes from a liquid to a gas at its boiling point (100.0 °C). See Table 11.7 for heats of vaporization.

Verified step by step guidance
1
Determine the number of moles of water: Use the molar mass of water (18.02 g/mol) to convert the mass of water (55.0 g) into moles.
Identify the heat of vaporization: Look up the heat of vaporization for water at its boiling point, which is typically given in kJ/mol.
Calculate the total heat absorbed: Multiply the number of moles of water by the heat of vaporization to find the total heat absorbed during the phase change.
Convert the heat absorbed to the same units as entropy: Since entropy is often expressed in J/K, convert the total heat absorbed from kJ to J.
Calculate the change in entropy: Use the formula \( \Delta S = \frac{q_{rev}}{T} \), where \( q_{rev} \) is the heat absorbed (in J) and \( T \) is the temperature in Kelvin (373 K for water at boiling point).
Previous problem
Next problem
Related Practice
Textbook Question

Calculate the change in entropy that occurs in the system when 1.00 mole of isopropyl alcohol (C3H8O) melts at its melting point (-89.5 °C). See Table 11.9 for heats of fusion.

2701
views
1
rank
1
comments
Textbook Question

Calculate the change in entropy that occurs in the system when 1.00 mole of diethyl ether (C4H10O) condenses from a gas to a liquid at its normal boiling point (34.6 °C). See Table 11.7 for heats of vaporization.

2997
views
Open Question

What is the change in entropy that occurs in the system when 45.0 g of acetone (C3H6O) freezes at its melting point (-94.8 °C)? Use Table 11.9 for the heats of fusion.

Textbook Question

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. 2 KClO3(s) → 2 KCl(s) + 3 O2(g) c. Na(s) + 2 Cl2(g) → NaCl(s) d. N2(g) + 3 H2(g) → 2 NH3(g)

3407
views
Textbook Question

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. b. CH2=CH2( g) + H2( g) → CH3CH3( g)

463
views
1
rank
Textbook Question

Without doing any calculations, determine the sign of ΔSsys for each chemical reaction. a. Mg(s) + Cl2(g) → MgCl2(s) b. 2 H2S(g) + 3 O2(g) → 2 H2O(g) + 2 SO2(g) c. 2 O3(g) → 3 O2(g) d. HCl(g) + NH3(g) → NH4Cl(s)