0 votes
64 views
in Physical Chemistry by (430 points)
A beaker of water is placed on a hot plate, and the temperature is gradually increased. Write an equation for the rate of change of entropy with respect to time during this process, assuming the system is not in equilibrium. Use the equation to determine the rate of entropy production in the water as it is heated from 25°C to 100°C at a constant rate of 2°C/min.

1 Answer

0 votes
by (570 points)
To determine the rate of change of entropy with respect to time, we can use the equation:dS/dt = dQ/dt *  1/T where dS/dt is the rate of change of entropy, dQ/dt is the rate of heat transfer, and T is the temperature in Kelvin.First, we need to find the rate of heat transfer  dQ/dt . We can use the equation:dQ/dt = mc *  dT/dt where m is the mass of the water, c is the specific heat capacity of water, and dT/dt is the rate of temperature change.Given that the water is heated at a constant rate of 2C/min, we can convert this to Kelvin per second:dT/dt = 2 K/min *  1 min/60 s  = 1/30 K/sThe specific heat capacity of water is approximately 4.18 J/ g*K . Assuming we have 100 g of water in the beaker, we can calculate dQ/dt:dQ/dt =  100 g  *  4.18 J/ g*K   *  1/30 K/s  = 13.93 J/sNow we can find the rate of entropy production as the water is heated from 25C to 100C. Since the temperature is changing, we need to integrate the equation for dS/dt over the temperature range:S =  dQ/dt *  1/T   dTWe can substitute the values we found for dQ/dt and the temperature range in Kelvin  298 K to 373 K :S =  13.93 J/s *  1/T   dT from 298 K to 373 KTo solve this integral, we can use the natural logarithm function:S = 13.93 J/s *  ln 373 K  - ln 298 K   = 13.93 J/s * ln 373/298 S  13.93 J/s * 0.223 = 3.11 J/ K*s So, the rate of entropy production in the water as it is heated from 25C to 100C at a constant rate of 2C/min is approximately 3.11 J/ K*s .

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...