If you drop a 50 gram piece of metal that has a temperature of 110°Celsius into 1000 grams of water at 25°Celsius, what best describes what would occur? (2 points) The water will quickly reach the boiling point. The water's temperature will stay the same, but the metal will cool down. The water's temperature will increase, and the metal will stay constant. The water and the metal's temperature will reach the same temperature. I want to go with D on this one
Which of the following circumstances will result in a reaction that is spontaneous at all temperatures? positive enthalpy change and positive entropy change negative enthalpy change and negative entropy change positive enthalpy change and negative entropy change negative enthalpy change and positive entropy change This one I'm really not very sure, but thinking A
D. For thermodynamics two bodies will reach the equilibrium, so the same T.
For a reaction at constant temperature and pressure, ΔG in the Gibbs free energy is: \[ \Delta G = \Delta H - T \Delta S \\] The sign of ΔG depends on the signs of the changes in enthalpy (ΔH) and ENTROPY (ΔS), as well as on the absolute temperature (T, in kelvin). ΔG changes from positive to negative (or vice versa) where T = ΔH/ΔS. When ΔG is negative, a process or chemical reaction proceeds spontaneously in the forward direction. When ΔG is positive, the process proceeds spontaneously in reverse. When ΔG is zero, the process is already in equilibrium, with no net change taking place over time.
Positive enthalpy change and positive entropy change |dw:1438458705959:dw| dg will be negative only is DH is smaller numer that DS, or if T are Negative enthalpy change and negative entropy change DG will be always positive |dw:1438459031853:dw| Positive enthalpy change and negative entropy change DG will be always positive |dw:1438459180415:dw| Negative enthalpy change and positive entropy change Will be always negative |dw:1438459241694:dw|
i'm confused which is spontaneous? meaning what?
You know that for spontaneus reaction DG must me negative. Up there i wrote you a formula of the DG, now analyze every case putting positive if increasing or negative if decreasing enthalpy (ΔH) and entropy (ΔS). And you will see that only in the last case the DG will be negative at any T.
ohhhhh I see now..
so it would be the last option
omgg yay! :)) thank you so much for that explanation :))
this is one is confusing mee As people eat food containing potassium, some of it undergoes beta decay. When this occurs, what element will be the product? A) Argon B) Calcium C) Chlorine D) Scandium
it might be argon :/
In nuclear physics, beta decay (β-decay) is a type of radioactive decay in which a proton is transformed into a neutron, or vice versa, inside an atomic nucleus. from: https://en.wikipedia.org/wiki/Beta_decay So if K had atomic number 19 (proton number), so when K decay loose one proton (which become a neutron) so now it atomic number is 18, which is Argon.