1. Perform the following unit conversions by hand. The unit conversion feature on your calculator may be used to check your work.

Transcription

1 SOLUTIONS CHAPTER 2 EXERCISES 1. Perfr the fllwing unit cnversins by hand. The unit cnversin feature n yur calculatr ay be used t check yur wrk. a. Cnvert 4000 gras int punds. lb = ( 4000g ) = 8.82 lb 45.g b. Cnvert 27.4 feet t eters. = ( 27.4ft ) = ft c. Cnvert 80 years t secnds. 5d 24hr 0in 0s 80yr = s yr 1d 1hr 1in = ( ) 9 d. Cnvert 55 ph int a speed f n per secnd = = hr 1i 1k 0 in 0s s 9 55i 1.1k n 1hr 1in 10 n e. Cnvert gallns int L..785L 1000L = ( 0.004gal) = 15.14L 1gal L f. Cnvert 10.8 t angstrs. c A 8 = ( 10.8) A 8 = c g. Cnvert 87ºF int Celsius and Kelvin. 5 = ( ) = 9 87 F 2 0. C = 0. C = 04 K Slutins Ch 2 July 1,

2 h. Cnvert 54ºC t degrees Fahrenheit. 9 = ( ) + = 5 54 C F i. Cnvert 1.2 atspheres t newtns per square eter (pascals). 101,70Pa = ( 1.2at) = Pa r 1at N 2 j. Cnvert 20.4 kilcarlries t jules kj 1000 J = ( 20.4 kcal) = 85,54 J 1kcal 1kJ k. Cnvert 1000 egawatts t hrsepwer 1000kW 1.4hp = ( 1000MW) = hp 1MW 1kW l. Cnvert 20.8 ft/s t i/hr. ft i 0s 0 in = 20.8 = 14.2ph s 5280ft in hr 2. A cube ccupies 0.58 ft. What is its vlue in? 12 in 2.54 c 10 = ( 0.58ft ) = ft 1 in 1 c A bx easures 4.5 ft in length, yd in width, and 8.12 inches in height. Deterine its vlue in cubic centieters. L 12in 2.54c = ( 4.5f t ) = 12.59c ft in ft 12in 2.54c W = ( yd) =.55c 1yd 1ft in 2.54c H = ( 8.12in) = 20.2c 1in Slutins Ch 2 July 1,

3 V = L W H = 9747c 4. The density f a given bject is knwn t be lb/in. Deterine its density in g/l. 4 lb 45.g 1in g ρ = = in lb 2.54 c c 5. A Styrfa cler is ade with utside diensins f 4.00ft.00ft 2.00ft and with inside diensins f.50ft 2.50ft 1.50 ft. Assue the average density f the Styrfa is 0.0 g/c. Deterine the vlue f Styrfa used in cubic eters and the weight in punds. styrfa ut in ( ) ( ) V = V V = 4 2 ft ft 1 V ( ft ) c.28 ft 5 styrfa = = = 5 Mass Styrfa = ( ) 0.0g lb.1 10 c 20.5lb = c 45.g. Cnsider a piece f platinu having a vlue f 1.4 L and ass f 28.8 g. Calculate the density f platinu in g/l. 28.8g g ρ = = L L 7. A liter f water was fund t cntain 5 g f benzene (C H ). What is the cncentratin f benzene in (a) g/l, (b) pp, and (c) larity? (a) 5 g/l (b) Recalling the 1 pp ~ 1 g/l gives 5 pp (c) MW f C H = = 78 5g g l benzene = L 1000g 78g M 8. The density f ethanl is g/l. Find the ass f 20 L f ethanl g = ( 20L) = 15.78g L Slutins Ch 2 July 1,

4 9. A ass f g f calciu carbnate (CaCO ) has been added t a cylinder cntaining water. The cylinder diaeter is 1.5 in. and the depth f the water in the cntainer is 5 in. Deterine the cncentratin f the salt in slutin shwing yur answer in units f (a) g/l, (b) Mass %, and (c) larity Vwater = πr h= π 5 = 8.84in c = ( 8.84in ) = 145c = 145L 1in (a) 0.525g 1000g 1000L g = L 1g L L 1g 145L = 145g H O L (b) ( ) g % g = Mass % = ( + ) (d) MW f CaCO = = 100 g g l CaCO = M L 1000g 100g CaCO 10. The sulfur dixide (SO 2 ) stack gas cncentratin fr fssil fuel cbustin is 2 ppv. Deterine the stack gas SO 2 cncentratin in units f µg. Assue STP. µg ppv MW 10 2ppv 4 10 µg = = = Calculate the vlue f 1 le f SO 2 at 25ºC and 1 at. Express yur answer in. 24.5L ( 1l SO 2) = SO2 1l SO2 1000L 12. The ske inhaled fr a cigarette cntains apprxiately 400 ppv carbn nxide. Express this cncentratin as a percentage f air inhaled. 400 x 400ppv = = 0.04% Slutins Ch 2 July 1,

5 1. The average exhaled carbn dixide (CO 2 ) cncentratin fr a huan breath is 4%. Cnvert this cncentratin value t ppv. 4 x ppv 4% = = 40, 000ppv Fill a rigid cylinder with a vlue f 25.0 L with nitrgen gas t a final pressure f 20,000 kpa at 27ºC. Deterine the les f N 2 gas the cylinder cntains. PV = nrt 1at ( 20,000kPa)( 25L) PV kpa n = = = 200 l RT Lat ( ) K K l 15. A 1 kg blck f dry ice (slid CO 2 ) vaprized t gas at r teperature. Deterine the vlue f gas prduced at 25ºC at 975 kpa. 1000g ( 1kg) kg ass Lat RT ( ) K MW ( 44g l) K l V = = = 57.8L P 1at ( 975kPa) kpa 1. Assue the discharge fr a wastewater treatent plant has a flw f 0 MGD with a slids cncentratin f 5 g/l. Deterine the ass flw rate f slids discharged in unit f lb /day. g Mgal lb -L lb L d g-mgal day Q = C Q = =1, Cnsider a rectangular wastewater treatent cell having a length f 100 ft, width f 20 ft, and depth f 20 ft. If the flw int the cell is 50 ft /in, calculate the residence tie f the treatent cell. ( ) ft V θ = = = 800in Q ft 50 in Slutins Ch 2 July 1,