Question

6) Consider the diagras given below: HCl(aq) 21.8 ca Zn(s) water 7.10 al of 6.0 M HCl are added to 0.186 g Zn(s) in a test tube. a) Write a balanced equation for the reaction taking place. Zn + 2 Hell - ZnCl₂ + b) The liberated H,(g) is collected by displacing water from an eudlometer, a graduated glass measuring tube for gas analy13. After the reaction is complete, the volume of H() collected above water is 72.18 ml at 18.8°C. The height of water column in the eudiometer is 21.8 cm and the atmospheric pressure is 753.2 na 1. At 18.8°c the density of Hg is 13.6 g/cn' and the water vapor pressure 13 17.54 torr. Calculate the ideal gas constant, R, from the information given. Setup: 6:0M = x moles/0.017 moles= 0.06 moles-0.1868/65 g/mol moles 0.003 I mol zinc = a moles HC ) ,06 mol = 0.006 .006 2n + 0.06 HCl 0.0062ncl2 +0.006H2 n=lmol PV=nRT 17.54 (72, 18)= 1118.8 1266=1886 18. 68

Answer 1

10 mL § 6.0 HHO mole of He = = = Molanity & Volume in Litore 6 x (lo X103j 0.06 mole mass of zinc (znla 0.186,2 Molar mass (zn) = 65-38 almos Mole & Zn = 0.186 = 2.844 x 103 mole -0.002844 mole Chemical reaction Zn + 2uce > Zn caz & Hz 보 mole 2 mole I mole

1 mole zu react with = 2 mole rile 0.002844 mole zn ² 2x01002844 Hel . i 0,005688 , mole rile So we have excess mok of nice ( we have olor mole rice) than nee → excess reactant Zn → Limiting reactant Now a mole zn = 0.002844 mole zu = I mole Hz produced Hz produced 01002844 mole hue= 0.002844 mol Volume & M₂ Collected a 72.18 m2 = 72.188103 L

Height of water = 21.8 cm = 218 mm H2O = 218 mmiro x 1 mm Hg 13.6 mm H2O - 16.0294 mm Hg Pn, Tz 18.8°C =(18.8+273-15 )k = 291-95 P gas colledea = [/atmospheric - 16.0294 mmity - Pwater vaper] = [753.2 mming - 16.0294 mmity - 17.54 mm Hg 1. 1 mmry 24 tour • 1 atm - 719.6306 mm Hg - 119.6306 atm 75312 = 753.2 119.6306 - atm minuty = 0.9554 cutin

Acoc. to Ideal gas law - pv=nR7 R = PV - ogssu (atm) x 72.18 x103 (L) 0.002844 (mole) X 291.95(k) R = 0.08305 Liath Mole .ko True value % error = of R= 0.08205 Lialm Molek 0.08305 -0.0826560 Xloo 0:08205 %error = [experimental - true value] * 100 = 1.2187 % true value 1,2187 o error a large image value] * 200

Molar Volume & Hz 291.95 T = V = R7 - 0.08305 x 291.95 0.9554 L/mole K2 TV = 25.3783 L More