Calculate the amount of heat needed to convert 15.0 g of liquid water at 87 ºC to steam at 135. ºC.

45,765 J

815 J

33,900 J

35,807 J

The total heat required is 35807 J

Explanation:

Step 1: Data given

Mass of water = 15.0 grams

Initial temperature of water = 87.0 °C

Temperature of steam = 135.0 °C

ΔHfus = 334 J/g

ΔHVap = 2260 J/g

Step 2: Calculate heat required to heat water from 85 to 100 °C

Q = m*c*ΔT

⇒Q = the heat required = TO BE DETERMINED

⇒m = the mass of water = 15.0 grams

⇒c= the specific heat of water = 4.18 J/g°C

⇒ΔT = the change of temperature = T2 - T1 = 100 - 87 = 13°C

Q = 15.0 * 4.18 J/g°C * 13 °C

Q = 815.1 J

Step 3: Calculate heat required to change water at 100 °C to steam

Q = m * ΔHVap

Q = 15.0 grams * 2260 J/g

Q = 33900 J

Step 4: Calculate heat required to heat steam from 100 °C to 135 °C

Q = m*c*ΔT

⇒Q = the heat required = TO BE DETERMINED

⇒m = the mass of water = 15.0 grams

⇒c= the specific heat of steam = 2.09 J/g°C

⇒ΔT = the change of temperature = T2 - T1 = 135 - 100 = 35°C

Q = 15.0 * 2.09 * 35 °C

Q = 1097.25 J

Step 5: Calculate the total heat required

Q = 35807 J

The total heat required is 35807 J

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