Question

1211 L postlab Calorimetry - in both cases ignore the calorimeter A 248-8 sample of copper is dropped into 390 to be 39.9"C. Calculate the initial temperature of the copper. Density of water 1.00/mL. Specific heat of copper - 384 1/8" 590 R of water at 22.500 The final temperature wash When 50.0 mL of .10 M HCl and 50,0 mL of .10 M NAOH, both at 22°C. are added to a calorimeter, the temperature of the mixture reaches 28.9°C. Calculate the heat produced by this reaction. Density of water 100g/mL. Specific heat of water = 4.184 1/8°C A student masses 5,34 g of NH.CI, and adds it to a calorimeter containing 100.0 mL of water at 21.0°C As the salt dissolves, the temperature drops to 17.6 'C. Calculate the AH.. of ammonium chloride in kl/mol. Is the process endothermic or exothermic? Explain. Density of water 1.00g/mL. Specific heat of water 4.184 1/8 °C

Answer 1

For Water - Tj = 22.6.0 072174 - Til - t = 39.9°C 17.30 heat gained by water - mcat F 390x4 · 184 X 17.3 • 28, 229. 45 I Since heat by w e heat gained wata by lost Copper. heat lost by copper - a m coT m= moss of copper = 248 gon c = 3847 lg c. sigh shows that heat got tive lost- - 28, 229.457 = 248 gm x 384 Ilgic XOT DT AT It-T Ti = 7 i = = 0.296. - 0.3°C -0.3 Tt + 0.3 39.9 +03 40.2'G. Ti = 22°c Ips 28.9.c - AT = Tt - Ti = 6.900 Total valome of mixture se water = 100 ml moss of C = mixture = 4.184 alge 100gm L d = 1 g) ml ]

- heat produced by reaction & MEST - - 100 x 4.184 X 6-9 28.86.96 Joule 2.89 KJ - mass of water = loogm { d = Ign land ? It = 17.6°C Ti 21.0c OT= 1 It - Til = 3.4.6. heat al dissalition : m cOT loo X 4.8 4X 3.4 - 1422.56 Joule Endir males of Nnya = mass malar mass 5.34 gm 53.4 o.1 mal. کے کرنے heat of dissalution mals 1422.56 0.1 mal 14225 6 bulmal on - 14.23 kJ l mal.