Question

im 2. The volume of a gas is 3.90 I at 72° C. What will the volume become if the temperature is changed to -18° C at constant pressure? HINT: Use combined law with Tin kelvins. K = C + 2713.16 - On the final, no hints, no equations will be given, just constants and a periodic table. So prepare accordingly. P1V/ (natı) = P2V2/(n2T2) 3. How many moles of helium gas must be added to a balloon currently holding 6.00 moles in order to increase the volume from 124 L to 175 L? HINT: Use PV / (niti) - P2V2/ (n2T2) Then find n2 and subtract 6.00 moles from it. Assume and T are constant. 4. What will be the volume of 0.465 moles of argon at 15° C and 735 torr? HINT: PV = nRT where R = 0.0821 L'atm/ (mol.K) Tin K = 273.16 + C 5. How many grams of 2n must react with hydrochloric acid in order to produce 4.35 L of hydrogen gas, measured at STP? HINT: 1 mole - 22.4 L at STP. Zna: + 2HCl(aq) + ZnCl2 + Higi T K 6. What is the density of propane, CyHe at STP? D = HINT: 1 mole - 22.4 L at STP 7. What is the molar mass of an unknown gas, which has a density of 8.28g/L at 740 torr and 270 C? HINT: 1 mole = 22.4 I at STP. Or solve PV - nRT for n. Then n = mass/MW

Answer 1

the solution of the questions are as below:

2 Pivi P₂ V2 in Tan, T, at constant pressure and mores, 10,= 3.90 L T = 273.16 472 = 34 Sadok ₂ = ? T2 = 273.16-18=255.16k OY 3.90 345.16 V2 255:16 so the final volume is a 2.882 OY V2 -2.88 1. P&T are constants, V = 124 L 12 = 6.00 mores | ₂ = 175L m2 = 2 1. 0 12.4 - 6. (8.47-6.0)-'2-47 moles of helium must be added. Op m2 ~ 8.47 +60 $ 0 PV = nRT I P = 735 ton = 735 0.97 atm 0.97XV=0.465x0.06 V =2 X 228.16 0.465 R 0.0821 L atm (mol) V 11.34 T: 273.16 + 5 = 288-16K o the volume will be - 11-34 L OY - Zn + 1 mole 2HCl 2 mile 2n Cl2 + Ha Imole 1 moke 22.4L - mole 4,35 L 4.35* 0.194 mole 22.4 4.35 To produce 4.352 of H₂ gas ie D.194 mie of H₂ gas, 0.194 mole of an is required. % Now - 1 mole zn = 65.38 grams 0.1944 = 65.38X0-194) - 12.68 grams. o 9.12:68 grams of 2n required.