Question

can you please help me with #3, #4 & #5?

3. A sample of nitrogen gas expands in volume from 2.2 L to 4.6 L at constant temperature. Calculate the work done in joules if the gas expands against: Pext exkemal pressreW-pextlVF-Vi a. a vacuum. b. a constant pressure of 0.65 atm. c. a constant pressure of 2.7 atm. Consider the following data: 4. AI Cu Metal Mass (g) Specific Heat, J/g °C Temperature, °C 10 30 0.900 0.285 60 40 sod srl sluolaO 8 aicrnabsh these two metals are placed in contact, which of the following will take place?em a. Heat will flow from Al to Cu because Al has a larger specific heat. b. Heat will flow from Cu to Al because Cu has a larger heat capacity. c. Heat will flow from Cu to Al because Cu is at a higher temperature. d. Heat will flow from Cu to Al because Cu has a larger mass. e. No heat will flow in either direction. 5. Calculate the amount of heat liberated (in kJ) from 262 g of copper when it cools from 87.0 °C to 11.8°C. The specific heat of Cu is 0.385 J/g °C.

Answer 1

Solution given unlus. (5) Specific. heet.(cp) 0.385 J--- gºc Ti . 896: 87 + 273 -_.360 Th 1 1'8'C : 11:8 +273 : 284.8. mass. (m) . 262.9 LQ_8( Meel:) ? O m AT CR- : 262_4 ( 284.8 – 360 )* 01385 J = 5 : 262 (-75.2) x 0.385 J 7.5 85.424.J_ 7:585_KI Ans. Q Q - 7.585 kJ / Ane