Water standing in the open at 30.7°c evaporates because of the escape of some of the surface molecules. the heat of vaporization (550 cal/g) is approximately equal to εn, where ε is the average energy of the escaping molecules and n is the number of molecules per gram. (a) find ε. (b) what is the ratio of ε to the average kinetic energy of h2o molecules, assuming the latter is related to temperature in the same way as it is for gases

What is the magnitude of the resultant vector round your answer to the nearest tenth

The boy of mass 30 kg is at r1= 2 meters from the fulcrum. of the girl is 45 kg, at what r2 must she sit so that they are balanced ?

1. how much energy is needed to raise the temperature of 40.0 g of argon from 25c to 40c? the specific heat capacity of argon is 0.520 j/(g·k) 2a. 23.0 ml of 0.100 m hcl (standard) are added from a buret to neutralize 50.0 ml of an unknown basic solution. 2b. if the oh- produced in the previous reaction came from ca(oh)2, then what is the molarity of the ca(oh)2? 3.calculate the new freezing-point of a solution when 60.5 grams of cacl2 solute is dissolved in 0.612 kg of water. 4. what is the maximum number of moles of alcl3 that can be produced from 5.0 mol al and 6.0 mol cl2? 5. a sample of oxygen gas has a volume of 150 ml when its pressure is 0.923 atm. if the pressure is increased to 0.987 atm and the temperature remains constant, what will the new volume be? 6. nitrogen gas in a closed container at a temperature of 100.0 oc and 3.0 atm is heated to 300 oc. what is the pressure of the gas at the higher temperature?