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Anonymous asked in Science & MathematicsChemistry · 2 years ago

Chem math questions!! Please help!!!?

A 47 g piece of ice at 0.0 ∘C is added to a sample of water at 6.4 ∘C. All of the ice melts and the temperature of the water decreases to 0.0 ∘C. How many grams of water were in the sample

A patient arrives in the emergency room with a burn caused by steam. Calculate the heat that is released when 13.9 g of steam at 100. ∘C hits the skin, condenses, and cools to body temperature of 37.0 ∘C. (For water, 540 cal (2260 J) is needed to convert 1 g of water to vapor at 100 ∘C.)

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  • 2 years ago
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    A 47 g piece of ice at 0.0°C is added to a sample of water at 6.4°C. All of the ice melts and the temperature of the water decreases to 0.0°C. How many grams of water were in the sample.

    Latent heat of fusion of water at 0°C = 334 J/g

    Heat capacity of water = 4.18 J/g°C

    Heat absorbed by the ice = (47 g) × (334 J/g) = 15700 J

    Heat released by the water = (m g) × (4.18 J/g°C) × [(6.4 - 0)°C] = 26.76m J

    Heat released by the water = Heat absorbed by the ice

    26.76m = 15700

    m = 586.7 ≈ 590 (to 2 sig. fig.)

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    A patient arrives in the emergency room with a burn caused by steam. Calculate the heat that is released when 13.9 g of steam at 100.°C hits the skin, condenses, and cools to body temperature of 37.0°C. (For water, 540 cal (2260 J) is needed to convert 1 g of water to vapor at 100 ∘C.)

    Heat released when 100°C steam → 100°C water = (13.9 g) × (540 cal/g) = 7506 cal

    Heat released when 100°C water → 37.0°C water = (13.9 g) × (1.00 cal/g) × [(100 - 37)°C] = 876 cal

    Heat released to hit the skin = (7506 + 876) cal = 8382 cal ≈ 8380 cal (to 3 sig. fig.)

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