In a process facility, you have two liquid streams with only methanol and water coming in from two separate processes. Stream 1 contains 80% of methanol by moles and Stream 2 contains 30% of methanol by moles. Your manager says you need to mix these together and flash it in a column. The temperature of operation is 400 K and you need to operate at a pressure that is nearly the average of the vapor pressures of methanol and water at 400 K. The VLE plot for methanol and water at 400 K is given to you (see below). (a) What is the vapor pressure of methanol and water? What is the operating pressure? You can round off the operating pressure to the nearest integer for further calculations (1.5 points) (b) What will be the composition of liquid and vapor product if you flash Stream 1 and Stream 2 individually (without mixing) at the operating pressure and temperature? (2 points) (c) Your manager now tells you that he needs half of the net product as a vapor. What ratio of streams 1 and 2 should you mix and flash at given operating pressure and temperature so as to get the desired product? (7 points) (d) Now you take the product vapor and liquid from (c), mix it and pass it through another flash drum operating at 400 K and 65 atm pressure. What is the composition (mole fractions) of your final liquid and vapor product? Approximate values are acceptable (1.5 points)

The answer to your question really depends on three things: how much water you have, how cold it is to start out, and how cold the things around it are. water actually freezes when it gets to 32 degrees fahrenheit (0 degrees celsius), but the time it takes to get there may be different.  let's start with the first. if you take two glasses, and fill one with a tiny bit of water, and the other about halfway, then put them both in the freezer, the one with less water will freeze first (you can try this at home, but i recommend using plastic cups and not glass ones).  now let's move on to the second part. let's say you have two glasses, and you fill one with really cold water that has been in the refrigerator, and the other with really hot water from the sink. if you put both of them in the freezer, the one that started out colder will freeze first.  for the third part, let's imagine that you have two glasses with the same amount of water in them, and the water is at the same temperature. imagine putting one outside on a really really cold day in georgia, and having a friend in alaska put one outside on the same day. since it would be so much colder in alaska, the glass of water there would freeze before yours.  so, if you took a tiny bit of really cold water in a glass, and put it outside on a cold day in alaska, it would freeze a lot faster than a big glass of hot water outside on a cold day in georgia. 

Theoretical temperature at which molecules stop moving and no more heat can be removed from the object. kelvin: absolute zero degrees. none of the above.