In: Chemistry
PART A A 25.00 mL sample of 1.5 M hydrobromic acid is reacted with a 45.0 g sample of calcium. a. How many moles of hydrogen gas are produced in the reaction? . What volume of hydrogen gas (in mL) is produced at 28.6ºC and 786.5 mm Hg?
PART B. All gases display non-ideal behavior (i.e., they are real gases) in two general situations: at high pressure or at low temperature. What component(s) of the ideal gas model is (are) no longer valid when a gas is at a high pressure or at a low temperature? Explain your reasoning using a particulate-level model of a gas.
PART C A sample of ammonia gas in a 200.0 mL container has a temperature of 16ºC and a pressure of 0.93 atm. What volumes of nitrogen and hydrogen gas are required to produce this much ammonia if all gas have the same temperature and pressure?
PART A
Molarity of HBr = 1.5 M
Volume of HBr = 25 mL = 0.025 L
Moles of HBr = Molarity * Volume = 1.5 M*0.025 L = 0.0375 mol
Mass of Ca = 45 g
Molar mass of Ca = 40 g/mol
Moles of Ca = Mass/ molar mass = 45 g/(40 g/mol) = 1.125 mol
Reaction is:
2HBr + Ca CaBr2 + H2
From reaction, 2 mol of HBr reacts with 1 mol of Ca
Thus, 0.0375 mol of HBr reacts with 0.01875 mol of Ca
Thus, HBr is a limiting reagent
From reaction, 2 mol of Hbr produces 1 mol of H2
So, Moles of H2 formed(n) = 0.01875 mol
Temperature (T) = 28.6 oC = 301.6 K
Pressure (P) = 786.5 mmHg = 786.5/760 = 1.035 atm
FRom Ideal gas equation
PV = nRT
V = nRT/P = (0.01875 mol * 0.0821L.atm/mol.K * 301.6K) / 1.035 atm = 0.4486 L = 448.6 mL
PART B
ACCORDING TO KINEtic gas theory, Ideal gases have no force of attraction among molecules and Volume occupied by gas is also negligible. But when Pressure is high, particles come closer to each other and force of attraction become significant and as particle come closer, volume occupied by gas also becomes significant.
PART C
Reaction is:
N2 + 3H2 2NH3
Since temperature and pressure are constant. Therefore
200 mL = 0.2 L
So,2 Volume of NH3 is produced from 1 volume of N2 and 3 volume of H2
Hence, 0.2 L of NH3 is produced from 0.2/2 = 0.1 L of N2and 0.2*3/2 = 0.3 L of H2