A 2.00-kg block of ice at 0.00°C is dropped into a very large lake at 25.0°C?
A 2.00-kg block of ice at 0.00°C is dropped into a very large lake at 25.0°C and completely melts.
For water, the heat of fusion is 3.35 × 105 J/kg, the heat of vaporization is 2.25 × 105 J/kg, and the
specific heat is 4190 J/kg · K. The net change in entropy of the system consisting of the ice and the
lake during this melting process is closest to:
A) 2.06 × 102 J/K
B) -2.45 × 103 J/K
C) 2.24 × 103 J/K
D) 2.45 × 103 J/K
E) -2.06 × 102 J/K
Would you please solve the question for me, I am really getting confused
More Questions From This User See All
Answers & Comments
Verified answer
mi = 2 kg
Ti = 0 deg. C = 3 K
Ts = 25 deg. C = 298 K
Hfus = 335 kJ/kg
c = 4.19 kJ/kg
Entropy change of ice,
ΔSi = m* [ Hfus/Tfus + c*ln(Ts/Ti) ]
ΔSi = 2* [335/273 +4.19*ln(298/273)]
ΔSi = 3.1885 kJ/k
Entropy change of surrounding,
Q = m* [ Hfus + c*(Ts-Ti) ]
Q = 2* [335 + 4.19*25]
Q = 879.5 kJ
ΔSs = -Q/Ts
ΔSs = -879.5/298
ΔSs = - 2.9513 kJ/K
Nett entropy change
ΔS = ΔSi + ΔSs
ΔS = 0.237 kJ/K
ΔS =237 J/K = 2.37 * 10^2 J/K closest to (A) 2.06 × 10^2 J/K
Temperature of sunlight on its floor is arpund 6,000°C, yet in the middle it ought to get 13,000,000°C. so we are able to take 10,000,000°C as an widespread temperature. This warmth is feed by making use of nuclear reactions of in maximum cases hydrogen into helium and the carbon etc. Mass of sunlight is one million.ninety 8 ×10^30 kg The capability released by making use of the sunlight is W = 383 x 10^34 watts (Joules according to 2nd) we would desire to appreciate what may be the quantity of ice water mandatory to extinguish the sunlight. it ought to signify to get a minimum of a temperature of 0°C. We notice the definition of particular warmth: C= particular warmth of ice water = 2.114 J/g°C = 2114 J/Kg°C Q = mCT (we assume that each and one and all capability released by making use of sunlight (W) is switched over into warmth (Q)) 383 x 10^34 J = m (2114 J/Kg°C)(10000000°C) m = 383 x 10^34 J / (2114 x 10^10 J Kg°C) = one million.8117 x 10^26 kg So, we analyze the mass of water ice against the sunlight mass (one million.ninety 8 x 10^30 kg). sure, an ice block of one million/ten thousand the mass of sunlight ought to extinguish it to get 0°C. It does no longer would desire to be greater than sunlight, in simple terms 10,000 much less large than sunlight. the former calculations have been accomplished in a similar temper of your question. So we ought to think that an invisible and extremely useful hand drops the block directly onto the sunlight. If any obtainable needs me to superb them, they are welcomed. ADDENDUM: owing to scythian1950 to function the notice of the interior capability concern. I believe him pertaining to to this question as thrilling to think of roughly it (nonetheless the impossibility that this experience ever happens). i'm going to offer additionally an action picture star to the question. I in simple terms did the calculations as a "curious" workout. sturdy good fortune!