(5). Enter your answer in the provided box. A quantity of 1.922 g of methanol (C
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(5). Enter your answer in the provided box. A quantity of 1.922 g of methanol (CH30H) was burned in a constant-vol k.J /°C, calculate the molar heat of combustion of methanol. ume bomb calorimeter. uently, the temperature rose by 5.48°C. If the heat capacity of the bomb plus water was 9.59 J/mol (6). Enter your answer in the provided box. A piece of silver with a silver? mass 314 g has a heat capacity of 74.4 JPC. What is the specific heat of J/g ° (7). Select the single best answer. Consider the following data: Metal Mass (g) Specific heat (J / g·°C) 0.900 Temperature (C) When these two metals are placed in contact, which of the following will take place? Al 30 0.385 60 10 40 Heat will flow from Al to Cu because Al has a larger specific heat. Heat will flow from Cu to Al because Cu has a larger mass. Heat will flow from Cu to Al because Cu has a larger heat capacity. No heat will flow in either direction. Heat will flow from Cu to Al because Cu is at a higher temperature. Be sure to answer all parts. A gas expands and does PV work on its surroundings equal to 3.40 x 102 J. At the same time, it absorbs 128 J of heat from the surroundings. Calculate the change in energy of the gas. Note: PV work means work done by a changing volume against constant pressure. Enter your answer in scientific notation.Explanation / Answer
1.Mass of methanol =1.922 gm
Molar mass of methanol(CH3OH)=32
Moles of methanol= mass/molar mass= 1.922/32=0.060
Heat of combustion = heat capacity of calorimeter* temperature rise
=9.59*5.48 KJ=52.55 Kj
Since heat is released, the reaction is exothermic.
Hence heat of combustion/mole= 52.55/0.06=876 KJ
2.specific heat = heat capacity /mass = 74.4/314 J/gm.deg.c=0.24 J/gm.deg.c
3. heat always from high temperature to low temperature. Hence heat flows from copper to Al since copper is at 60 deg.c while aluminium is at 40 deg.c
4. change in internal energy= Q+W
Q= heat added or removed and W= work added or done also PV work
anything added to the system is +ve and leaving is -ve.
change in internal energy= 128-3.4*102= -212 Joules
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