Calculate the value of AE in joules for a system that loses 50 J of heat and has
ID: 1068700 • Letter: C
Question
Calculate the value of AE in joules for a system that loses 50 J of heat and has 150 J of work performed on it by the surroundings. 50 100 100 -200 +200 The change in the internal energy of a system that absorbs 2, 500 J of heat and that does 7.655 J of work on the surroundings is J 10.155 5, 155 -5.155 -10.155 1.91 times 10^7 The change in the internal energy of a system that releases 2, 500 J of heat and that does 7.655 J of work on the surroundings is J. -10, 155 -5, 155 -1 91 times 10^7 10, 155 5.155 When a system delta E is always negative. absorbs heat and does work gives off heat and does work absorbs heat and has work done on it gives off heat and has work done on it none of the above is always negative. Which one of the following is an exothermic process? ice melting water evaporating boiling soup condensation of water vapour Ammonium this cyan ate and barium hydroxide are mixed at 25 degree C: the temperature drops. delta H for an endothermic process is while delta H for an exothermic process is zero, positive zero, negative positive, zero negative, positive, negative The reaction 4AI(s) + 30_2 (g) rightarrow 2Al_2O_3(s) delta H degree = -3351 kJ is. and therefore heat is by the reaction. endothermic, released endothermic, absorbed exothermic, released exothermic, absorbed thermo neutral, neither released nor absorbedExplanation / Answer
1) B) 100 J
E = energy gained (input) - energy lost (output)
E = 150J - 50J .. .. E = (+) 100J
2) C) -5155J
By the first law of thermodynamics, Q=U+W.
Here, Q=2500, W=7655. Hence U=Q-W
=2500-7655=-5155J. So the internal energy
diminishes by 5155J.
3) B) same as above
4) B) gives off heat and does work
Negative enthalpy just means that heat is released during the course of a reaction. Or, to put it in official thermodynamic terms, it means that it is an exothermic reaction
5) C) Boiling Soup ( An exothermic process releases heat to the sorroundings)
6) E) positive, negative
A system that releases heat to the surroundings, an exothermic reaction, has a negative H by convention, because the enthalpy of the products is lower than the enthalpy of the reactants of the system
A system of reactants that absorbs heat from the surroundings in an endothermic reaction has a positive HH, because the enthalpy of the products is higher than the enthalpy of the reactants of the system.
7) C) exothermic, released
Forming a chemical bond releases energy and therefore is an exothermic process.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.