A hiker caught in a rainstorm absorbs 1.00 L of water in her clothing. If it is

Question

A hiker caught in a rainstorm absorbs 1.00 L of water in her clothing. If it is windy so that the water evaporates quickly at 20 ° C, how much heat is required for this process? Express your answer using three significant figures and include the appropriate units H = 2440 kJ Submit My Answers Give Up Correct Significant Figures Feedback: Your answer 2.45.106 J(-2450 kJ was either rounded differently or used a different number of significant figures than required for this part. rt B If all this heat is removed from the hiker (no significant heat was generated by metabolism during this time), what drop in body temperature would the hiker experience? The clothed hiker weighs 75 kg, and you can approximate the heat capacity of hiker and clothes as equal to that of water. (Moral: stay out of the wind if you get your clothes wet.) Express your answer using two significant figures and include the appropriate units. Submit My Answers Give Up Incorrect; Try Again; 5 attempts remaining rt C How many grams of sucrose would the hiker have to metabolize (quickly) to replace the heat of evaporating 1.00 L of water so that her temperature would not change? You can use the enthalpy of reaction at 25 C;the sucrose (s) reacts with oxygen (g) to give carbon dioxide (g) and water (1) Express your answer using three significant figures and include the appropriate units

Explanation / Answer

Part B:

Total heat=2440 KJ

Specific heat of evaporation for water = 4.187 KJ/KgK

Heat = Specific heat x mass x change in temperature

2440=4.187 x 75 x dT

dT = 7.77 K

Part C:

Total heat of evaporation = m x Latent heat = 1Kg x 2,260 kJ/kg= 2260 KJ

Enthalphy of sucrose reaction = -5645 kJ/mol

So, 1 mole = 342.3 grams

Enthalphy of sucrose reaction= - 16.49 kJ/gm

So, total mass of sucrose needed = 2260/16.49 gm = 137.04 gm

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