Answer:
Find it in the teacher desk by tomorrow 7:30
Explanation:
#6 should be the independent variable because that's the one you can control
Answer: The beaker in which water level has decreased more is the one that contains pure water.
Explanation: Even when water is not heated it can evaporate, that is because molecules move at different speed and those that are closer to surface can break the gass pressure and scape as water vapor.
The movement of molecules of water can be affected by the presence of solutes (salts or other soluble compounds) and increase the evaporation temperature. For this particular case, molecules of salt atract the water molecules (remember salt has ions and water is a dipole with partial charges) and do not let the water move freely which avoid them to scape to the surface.
Answer:
C. Scientists accepted the model at first but later rejected it.
Explanation:
Scientists accepted the model at first because it explained the hydrogen emission spectrum.
However, with the development of quantum mechanics, scientists had to modify the model (not reject it).
Electrons still had specific energies, but they no longer travelled in fixed orbits.
Instead, electrons had a probability of being found in a given region of space.
Answer:
it is possible to remove 99.99% Cu2 by converting it to Cu(s)
Explanation:
So, from the question/problem above we are given the following ionic or REDOX equations of reactions;
Cu2+ + 2e- <--------------------------------------------------------------> Cu (s) Eo= 0.339 V
Sn2+ + 2e- <---------------------------------------------------------------> Sn (s) Eo= -0.141 V
In order to convert 99.99% Cu2 into Cu(s), the equation of reaction given below is needed:
Cu²⁺ + Sn ----------------------------------------------------------------------------> Cu + Sn²⁺.
Therefore, E°[overall] = 0.339 - [-0.141] = 0.48 V.
Therefore, the change in Gibbs' free energy, ΔG° = - nFE°. Where E° = O.48V, n= 2 and F = 96500 C.
Thus, ΔG° = - 92640.
This is less than zero[0]. Therefore, it is possible to remove 99.99% Cu2 by converting it to Cu(s) because the reaction is a spontaneous reaction.
