A. 1,2,3. The solutions are getting lighter meaning the concentration is decreasing. Its most likely that water was added to dilute the solutions.
To get the value of ΔG we need to get first the value of ΔG°:
when ΔG° = - R*T*㏑K
when R is constant in KJ = 0.00831 KJ
T is the temperature in Kelvin = 25+273 = 298 K
and K is the equilibrium constant = 4.5 x 10^-4
so by substitution:
∴ ΔG° = - 0.00831 * 298 K * ㏑4.5 x 10^-4
= -19 KJ
then, we can now get the value of ΔG when:
ΔG = ΔG° - RT*㏑[HNO2]/[H+][NO2]
when ΔG° = -19 KJ
and R is constant in KJ = 0.00831
and T is the temperature in Kelvin = 298 K
and [HNO2] = 0.21 m & [H+] = 5.9 x 10^-2 & [NO2-] = 6.3 x 10^-4 m
so, by substitution:
ΔG = -19 KJ - 0.00831 * 298K* ㏑(0.21/5.9x10^-2*6.3 x10^-4 )
= -40
Answer : The molecular formula of the compound will be, 
Explanation :
Empirical formula : It is the simplest form of the chemical formula which depicts the whole number of atoms of each element present in the compound.
Molecular formula : it is the chemical formula which depicts the actual number of atoms of each element present in the compound.
For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is :
As we are given that the empirical formula of a compound is 
and the molar mass of compound is, 90.09 gram/mol.
The empirical mass of = 1(12) + 2(1) + 1(16) = 30 g/eq
Molecular formula = 
Thus, the molecular formula of the compound will be,
a) Group 2 elements have 2 electrons on their outer shell, so they form a 2+ charge.
b) they lose 2 electrons as they are transferred to the non metal.
c)They obtain this charge as when they are made into an ionic compound the 2 electrons on the outer shell are transferred to the non metal, meaning there are 2 more protons that electrons, giving it a positive charge.
hope this helps! :)
Answer:
The OH group
Explanation:
Benzhydrol contains OH hydroxyl group in its molecule while fluorene does not. At first glance, one would think that OH, which contributes to hydrogen bonding would causes melting point of benzhydrol to be higher than fluorene. <em>However, </em>the structure of benzhydrol, which is 2 benzene rings connected to center hydroxyl carbon (PhCOHPh), allows for each benzene rings in benzhydrol to rotate until both rings are perpendicular to minimize repulsive force. This prevents the molecule from stacking on each other due to its non flat shape, and thus, lowering its melting point in contrast to flat fluorene molecule.
