CHEM 210 EXAM 1 REVIEW QUESTIONS AND ANSWERS

What phase change is taking place if DHsub = 26.1 kJ/mol is being used to calculate the heat involved in the process) 1)Liquid to solid 2) Gas to solid 3) Solid to liquid 4) Liquid to gas 5) Solid to gas - ANSWER3 Diethyl ether, (CH3CH2)2O , used as a solvent for extraction of organic compounds from aqueous solutions, has a high vapor pressure which makes it a potential fire hazard in laboratories in which it is used. How much energy is released when 10 g is cooled from 50.0°C to 10.0°C? boiling point 34.5°C heat of vaporization 351 J/g specific heat capacity, (CH3 CH2)2O(l) 3.74 J/(g·K) specific heat capacity, (CH3CH2)2O(g) 2.35 J/(g·K)1) 1)6.55 kJ 2) 4.79 kJ 3) 14.0 kJ 4) 1.3 kJ 5) 4.67 kJ - ANSWER5 Which molecules or compounds in the following pair have the highest boiling point? NH3 or PH3 Ar or Kr 1) NH3 and Ar 2) NH3 and Kr 3) PH3 and Ar 4) PH3 and Kr 5) One of the pairs has the same boiling point - ANSWER1 Which of the following has a boiling point which does not fit the general trend? 1) HF 2) HCl 3) HBr 4) HI - ANSWER Which of the following atoms should have the greatest polarizability? 1) F 2) Br 3) P