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A hot 0.25-kg piece of iron is placed in a calorimeter containing room temperature water. How much heat is lost by the iron as it cools from 125C to 75C? How much heat is gained by the water?

5. The temperature of 2.500 kg substance rises from 20 oC to 60 oC when it absorbs 23,500 joules of heat. Calculate the specific heat capacity of the substance. What is the identity of the substance?

7. Using the specific heat capacities of water and steam, explain which would be a better coolant for your car's engine if equal masses of each were used.

8. A cube of lead has a temperature of 18C. A second identical cube of lead is twice as hot. What is the temperature of the second lead cube?

2. For each pair of substances, identify the substance that will take more energy to heat from 20C to 100C and explain why. Specific heat for water- 4180 J/kg°C. Specific Heat for silver- 235 J/kg°C. Specific heat for iron- 450 J/kg°C.
a. 30 g of water vs. 300 g of water

b. 500 g of iron vs. 500 g of silver

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2. For each pair of substances, identify the substance that will take more energy to heat from 20C to 100C and explain why. Specific heat for water- 4180 J/kg°C. Specific Heat for silver- 235 J/kg°C. Specific heat for iron-450 J/kg°C.
a. 30 g of water vs. 300 g of water
Q = mcpΔT
Q(water) = (0.03kg)(4180 J/kg°C)(100-20)
Q(water) = 10,032 J
Q(water) = (0.3kg)(4180 J/kg°C)(100-20)
Q(water) = 100,320 J
300g of water takes mroe heat than 30g of water.

b. 500 g of iron vs. 500 g of silver
Q = mcpΔT
Q(iron) = (0.5g)(-450 J/kg°C)(100-20)
Q(iron) = -18,000J
Q(silver) = (.5g)(-235 J/kg°C)(100-20)
Q(silver) = -9,400J
Iron gives off more heat than silver

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