<span>Valence electrons are those in the outer most orbital shell (the valence shell). Elements in the same column (group) have the same number of valence electrons. Hydrogen is in Group 1. If you were to look at a periodic table of the elements, Lithium is right under Hydrogen.
You are correct, the answer is D. Lithium.</span>
Molar mass Cu(OH)₂ = <span>97.561 g/mol
1 mol --------- 97.561 g
? mol ---------- 68 g
moles = 68 * 1 / 97.561
moles = 68 / 97.561
= 0.6969 moles
hope this helps!</span>
Caffeine is more soluble in dichloromethane and the both are separated by evaporating the solvent.
Caffeine is an organic plant material which is more soluble in non-polar solvents than in polar solvents. As such, caffeine is more soluble in dichloromethane than in pure water.
In order to carry out a liquid-liquid exaction of dichloromethane from a commercial teabag, the dichloromethane is mixed with water. The caffeine is found to be more soluble in the organic dichloromethane layer than in water.
The two solvents can now be separated using a separating funnel and the solution is evaporated to obtain the caffeine.
Learn more: brainly.com/question/967776
Answer:
B)−6,942 J
/mol
Explanation:
At constant temperature and pressure, you cand define the change in Gibbs free energy, ΔG, as:
ΔG = ΔH - TΔS
Where ΔH is enthalpy, T absolute temperature and ΔS change in entropy.
Replacing (25°C = 273 + 25 = 298K; 25.45kJ/mol = 25450J/mol):
ΔG = ΔH - TΔS
ΔG = 25450J/mol - 298K×108.7J/molK
ΔG = -6942.6J/mol
Right solution is:
<h3>B)−6,942 J
/mol</h3>
