Prelab Exp. 13. Meal gas law. 1. If the volume of the cylinder is 5500 mL and th
ID: 858841 • Letter: P
Question
Prelab Exp. 13. Meal gas law. 1. If the volume of the cylinder is 5500 mL and the pressure of the N2 in it is 2.5 atm. (temperature is 25 degree C) a. How many moles of nitrogen molecules are in the cylinder? b. How many grams of nitrogen are in the cylinder? 2. For the following reaction: Mg(s) + 2HCl(aq) right arrow MgCl2 (aq) + H2 (g) At 25 degree C and 1 atm, 0.0350 g of Mg reacted with excess amount of HCl. a. flow many moles of H2 will be produced? b. How many mL of H2 will be collected (assume hydrogen is an ideal gas)?Explanation / Answer
Ideal as law: PV=nRT
V=5.5 L
P=2.5 atm
T=25 deree celcius = 273 +25= 298 K
R=0.0821 L?atm?K?1?mol?1
1)a)n=(PV)/RT=.562 moles
1)b)grams of nitrogen = number of moles x molecular weight of N2 = .562 x 28 = 15.73 grams
2)a) from the reaction 1 mole of Mg produces 1 mole of H2
no. of moles of M=0 .0305/24.305 = 0.00125 moles
implies 0.00125 moles of H2 are produced.
PV = nRT
V= (0.00125)(0.0821)(298)/1 = 0.0305 L= 30.5 mL