Question

need a clear explanation on number 5 and 8 pretty please dont really understand what deltaH=0 means and for number 8 is there a formula that youre suppose to plug in?

Which of the following has AHºr=0? a) I20 b) H2O(1) c) H*(04 ) Hgo What is the Gibbs free energy of the following reaction? C3H8(g) + 10 O2(g) - 3 CO2(g) + 4H2O a)-599.44 kJ/mol (b) 2073.88 kJ/mol c) -2120.86 kJ/mold)-4171.24 kJ/mol Which of matter and energy is transferable in al insulated system? a) matter b) energy e) matter and energy heither (9 11 50. g of iron is 90.°C and is added to 100 g of water at 25°C in a constant-pressure calorimeter, what is the temperature of the metal and water when they reach equilibrium? a) 21°C (6)28°C d) 391°C c) gºc

Answer 1

Answer to question#5:

The $\Delta H_{f}^{0}$ is the standard enthalpy of formation. All elements which are in standard states have the standard enthalpy of formation value zero. Among the options I₂(l), the molecular iodine is in dissolved state. the standard state of molecular iodine is solid. Thus the deltaH^o_f is not zero. H₂O(l) is formed from the reaction of H₂ (g) and O₂ (g). Here, in the reaction the reactants and product are not in same state. Therefore, deltaH^o_f is not zero. For H⁺(aq); the H+ is considered gas. In H+(aq), the H+ ion is surrounded by water molecules and is in dissolved state. Therefore, deltaH^o_f is not zero. Only for Hg(l) is in standard state because elemental mercury is liquid.

Answer to question#8:

The Change in heat of the me Him and for water is How - Hm = Hw -mpe Che ST a mho CHO AT Where Cre and Cho is the specif Capality of iron and watery Lear Capacity of 100 respectively Ches 0.450 Jigre CHO = 4.18 J/goc - 50 x 0.450 × CT f-90) = 108 +4:18 + CTI -25) - 0.45T8 + 405 = 8.3671 - 209. (8.36 +0.45) Tt & 249.504 - 283