Gaseous ethane (CH,CH,) will react with gaseous oxygen (02) to produce gaseous carbon dioxide (CO,) and gaseous water (H,O). Suppose 23. g of ethane is mixed with 25.5 g of oxygen. Calculate the minimum mass of ethane that could be left over by the chemical reaction. Round your answer to 2 significant digits. Ox10

This year, like many past years, you begin to feel very sleepy alter eating a large helping of Thanksgiving turkey. Some people attribute this sleepiness to the presence of the amino acid tryptophan in turkey. Tryptophan can be used by the body to produce serotonin, which can calm the brains activity and help to bring on sleep. a. What mass in grams of tryptophan is in a 0.25-lb serving of turkey? (Assume tryptophan accounts for 1.0% of the turkey mass.) b. What mass in grams of tryptophan is in 0.25 quart of milk? (Assume tryptophan accounts for 2.0% of milk by mass and that the density of milk is 1.04 kg/L.)

Convert the following Celsius temperatures to Kelvin and to Fahrenheit degrees. a. the temperature of someone with a fever, 39.2C b. a cold wintery day, 25C c. the lowest possible temperature, 273C d. the melting-point temperature of sodium chloride, 801C

Many laboratories use 25C as a standard temperature. What is this temperature in kelvins?