Question

Answer problems 1 and 2

Post-Lab Problem 1 (5 points). A sample of helium was placed in a cylinder under a piston at 25.0°C and 5.95 atm of pressure. Then the initial volume was increased twice while the temperature was simultaneously reduced to 12.5°C. What was the final pressure of helium in the cylinder? Enter your answer in the box provided with correct units and sig, figs.: The final ). Answer: pressure was: Pin Post-Lab Problem 2 (5 points). A sample of potassium permanganate (KMnO2) reacts to completion with sodium oxalate (Na,C,02) in the following redox reaction: 2Mnog(aq) +50,02 (aq) + 16H*(aq) → 10C02(9) + 2Mn2+(aq) + 8H,O(1) The volume of carbon dioxide released by the reaction at 297 K and 1.00 atm was 138 L. How many moles of potassium permanganate reacted? The Universal Gas Constant is 0.082057 kr. Enter your answer in the box provided with correct units and sig. figs.: Answer: The number of moles of potassium permanganate reacted was

Answer 1

Date: Page: of Cylinder is closed so amount Helium sample is fixed so nlno of mole) = constant. PV=nRT iner are const pv= const. then . Pivi - Pe Va T Tz Given, Initial Condition final condition P, = 5.95 atm T=250 = 298k v = v P₂ = ? T2 = 12. 5 e = 955k Let 1 V₂ = 2V. T . PV - Pq xV₂ TIT 5.950X P₂ x 2X 285.5

o Po = 5.95 x 285.5 = 298 Date: - Page = 5.708 alma īs. 7oatin And ③ Giren balanced chemical reaction 2 MnOf cast 5 GO cart 16 Hoa loca(g) - +2mm Ear) + 8 HOL) cal of mole of co, :P1=nRT for gas (assuming ideal) en p=latm T=297k R = 0.082057 alm. lomatik v = 138 1 RT na PV * 138 0.0820578297 = 5.662 mole According to given chemicelar 2. 10 mde of co produced by 2 mole of Mno i la s ---2011 o 5.662mole 1 " . 2x 5.662 10 1,132 pole .: moles of KMnO4 = 1.132 mole And