1 Which statement is true regarding 1 mol of NH_{3} ?A) It contains 6.02 x 10^{23} atoms and has a mass of 17.04 g. B) It contains 6.02 x 10^{23} molecules and has a mass of 17.04 g. C) It contains 6.02 x 10^{23} atoms and has a mass of 17.04 u. D) It contains 6.02 x 10^{23} molecules and has a mass of 17.04 u. 2 In order to find the number of moles represented by a given mass of substance you need to knowA) Avogadro's number B) N_{A} C) the molar mass of the substance. D) the molar mass of the substance and the Avogadro constant 3 In order to find the mass of a given # of particles of a substance you need to knowA) Avogadro's number B) N_{A} C) the molar mass of the substance D) the molar mass of the substance and the Avogadro constant 4 Gas pressure isA) the amount of strain a gas is under measured in kPa B) the result of the frequency of collisions of the gas particles with the container C) the result of the force of the collisions of the gas particles with the container D) the result of the frequency and force of the collisions of the gas particles with the container. 5 Standard temperature and pressure are defined asA) 273CK and 101.3 kPa B) 25^{o} C and 101.3 kPa C) 0CK and 101.3 kPa D) 0^{o} C and 100.0 kPa 6 Avogadro's hypothesis states thatA) equal volumes of gas contain the same number of particles B) equal volumes of gas at STP contain the same number of particles C) equal volumes of gas at the same temperature and pressure contain the same number of particles D) when gases react, their volumes combine in simple whole number ratios. 7 The molar volume of a gasA) is commonly used in calculations as 22.4 L at STP B) of 22.4 L at STP is considered to be absolutely true only for ideal gases C) will change if the temperature and/or pressure change D) All of the above are true 8 What is the volume of 5.00 mol of He at STP?A) 112 L B) 22.4 L C) 4.48 L D) You need to know the temperature and pressure to answer the question. 9 How many moles are present in 5.6 L of O_{2} gas?A) 0.25 mol B) 22.4 mol C) 125 mol D) You need to know temperature and pressure to answer the question.