Thermodynamics

A system was heated using 400.0 J of heat, and its internal energy increased by 150.0 J. Calculate w. Was work done on the system or by the system?

-250J

Calculate the standard entropy of fusion of mercury at its freezing point. The freezing point of mercury is 234.3 K and the ∆𝐻&'(°of mercury is 2.292 kJ/mol.

0.009782 Kj/mol*k

How many joules of energy must be absorbed by 5.00 x 102 g of H2O at 50.0oC to convert it to steam at 120oC? Given the following:DHvap for water = 40.7 kJ/mol, CP,m (water) = 75.3 J/mol∙oC, & CP,m (steam) = 36.4 J/mol∙oC

1.25x10^6 kJ

Calculate the entropy change of the surroundings in J/mol when mercury, Hg, freezes at -49°C. The normal freezing point of mercury is -38°C. The ∆𝐻,-.= 2.292 kJ/mol at -49 °C.

10.2 J/mol*k 0.0102 Kj/mol*k

How much energy, in kJ, is needed to evaporate 50.0 g H2O if Hvap = + 40.7 kJ/mol?

112.739 or 113 kJ

What is the change in entropy,Delta S , in J/K when 7.87 mol of vibranium gas expands by a factor of 7 at constant temperature?

127.323

A protein has the three-dimensional shape of a cube. Each face of the cube has a different color. Consider a solution that contains 8 proteins. Due to the protein's density is sinks to the bottom of the solution and randomly rest solely on one face of the cube. How many possible arrangements of the protein can be formed?

1679616

Calculate the change in entropy (in J/K) when 3.00 mol N2(g) expands from 22.0 L to 44.0 L at constant temperature?

17.3 J/k

A substance with a mass of 21.435 g at 26.68 °C is placed in a calorimeter containing 48.736 g of water at 88.622 °C. If the final temperature of the system is 77.366 °C, what is the specific heat capacity (in J/g°C) of this substance? Assume the calorimeter absorbs/releases no heat and no chemical reaction occurs. The specific heat capacity for water is 4.184 J/g°C.

2.1126

Calculate the final temperature and the change in enthalpy when 500. J of energy is transferred as heat to 0.900 mol O2(g) at 298K and 1.00 atm at constant pressure. Treat the gas as ideal

317.09K

Example: Calculate the final temperature of a 200.0 g sample of stainless steel at 25.0oC after 743 J of heat have been provided to the system. Cs for stainless steel = 0.51 J/goC.24

32.3 celsius

Calculate the total entropy change for the combustion of magnesium, 2Mg(s) + O2(g) → 2 MgO(s) at 25°C under standard conditions. Given ∆𝑆ys.°= -217 J/K and ∆𝐻° = -1202 kJ

4.033 Kj/K 4.03x10^3 J/k

Calculate the change in entropy (in J/K) when 18.02 g of water is heated from 1.00oC to 20.0oC at constant pressure. The CP,mfor water is 75.3 J/mol·K

5.05 J/k

What is the change in enthalpy when 425 g of C6H12O6 is burned in the presence of excess oxygen gas?62Reaction EnthalpyC6H12O6 (l) + 6 O2 (g) 6 CO2 (g) + 6 H2O (l) + 3523 kJ

8310 kJ

100.0 grams of H2O(l) at 100.°C is mixed with 82.00 g of H2O(l) at 65.0°C. What is the final temperature of the mixture? The specific heat of H2O(l) = 4.184 J/g °C

84.2

Pos or neg Delta S The pressure of a gas increases while the gas is held at constant temperature.? The temperature of a substance increases while at constant volume.? A solid melts at its melting point.? The following reaction takes place: Mg2+(aq) + 2Cl-(aq) MgCl2(s)?

A) negative B) positive C) negative D) positive

How are equilibrium, entropy, and Gibbs free energy related?

Gibbs free energy describes the likelihood of a reaction to occur under specified conditions; ∆G is a measure of the change in entropy of the universe at a specified temperature. When ∆G = 0, the system is at equilibrium and there is no change in the entropy of the universe under these conditions.

In a given reaction at constant pressure, 45 kJ of energy left the system as heat and 30. kJ of energy left the system as expansion work. What are the values of H and U for this process? Is the reaction endothermic or exothermic?

deltaH = -45Kj deltaU = -75kJ