I need help with part b I already know how to do part a. Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the equation: CO2(s)→CO2(g). When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating carbon dioxide produces a dense fog often used to create special effects. In a simple dry ice fog machine, dry ice is added to warm water in a Styrofoam cooler. The dry ice produces fog until it evaporates away, or until the water gets too cold to sublime the dry ice quickly enough. Suppose that a small Styrofoam cooler holds 15.0 L of water heated to 86 °C. The specific heat of water is 4.184 J/g·°C. a) Use standard enthalpies of formation to calculate the change in enthalpy for dry ice sublimation. (The ΔHºf for CO2(s) is -427.4 kJ/mol, and for CO2(g) is –393.5 kJ/mol) Answer: 33.9 kj b) Calculate the mass of dry ice that should be added to the water so that the dry ice completely sublimes away when the water reaches 13 °C. Assume no heat loss to the surroundings. Answer Choices: 6.0 g 0.325 kg 6.0 kg 133 g 0.325 g
I need help with part b I already know how to do part a.
Dry ice is solid carbon dioxide. Instead of melting, solid carbon dioxide sublimes according to the equation: CO2(s)→CO2(g). When dry ice is added to warm water, heat from the water causes the dry ice to sublime more quickly. The evaporating carbon dioxide produces a dense fog often used to create special effects. In a simple dry ice fog machine, dry ice is added to warm water in a Styrofoam cooler. The dry ice produces fog until it evaporates away, or until the water gets too cold to sublime the dry ice quickly enough. Suppose that a small Styrofoam cooler holds 15.0 L of water heated to 86 °C. The specific heat of water is 4.184 J/g·°C.
a) Use standard enthalpies of formation to calculate the change in enthalpy for dry ice sublimation. (The ΔHºf for CO2(s) is -427.4 kJ/mol, and for CO2(g) is –393.5 kJ/mol)
Answer: 33.9 kj
b) Calculate the mass of dry ice that should be added to the water so that the dry ice completely sublimes away when the water reaches 13 °C. Assume no heat loss to the surroundings.
Answer Choices:
Trending now
This is a popular solution!
Step by step
Solved in 8 steps with 6 images
