Let's represent molecules with symbols as follows:
C₂O₄ = X
and
H₂O = Y
Then,
K [ Co (X)₂ (Y)₂ ]
Since Potassium (K) has an oxidation number of +1
To achieve neutrality, the oxidation number of the coordination sphere needs to equal -1.
Thus,
[ Co (X)₂ (Y)₂ ] = -1
Given that,
the O.N of X is -2
Therefore,
O.N of (X)₂ equals -4
Additionally,
O.N of H₂O is zero since it remains neutral. Therefore,
[Co - 4 + 0 ] = -1
Or,
Co = -1 + 4
Co = +3
Conclusion:
The oxidation number for the coordination sphere is -1, and the oxidation state of copper is +3.
To find the mass of oxygen in the specified compound, we require the molar mass for both the compound and oxygen. We also establish the relationship between the number of moles of oxygen per mole of the substance. The calculation proceeds as follows:
90.0 g ( 1 mol / 86.91 g ) ( 1mol O / 1 mol Cl2O) ( 16 g / 1 mol ) = 16.57 g O
<span>To determine the specific heat of a solid sample, I’d begin by measuring the mass of the solid. Then, I would prepare a sufficient quantity of water at room temperature to fully submerge the solid. This water would go in an insulated container. I'd then heat the solid to a known temperature. Next, I’d record both the temperature of the solid and the water. After that, I'd submerge the heated sample in the water, allowing them to reach thermal equilibrium. I would then note this final equilibrium temperature.
The temperature difference between the heated sample and the equilibrium state indicates the change in temperature of the solid. Given the known mass, initial temperature of the water, and the equilibrium temperature, I can calculate the energy transferred from the solid to the water.
With the mass of the sample, the change in temperature of the solid, and the transferred energy, I have enough information to find the specific heat of the solid sample</span>
The hydrogen bonds represent a type of intermolecular force.
This means it describes the attraction between molecules, which tends to keep them close to one another quite firmly.
Vaporization refers to the transition from a liquid state, where molecules are in close proximity, to a gaseous state, where molecules are more spread out. To achieve this separation, the robust hydrogen bonds must be broken, necessitating more energy compared to similar substances lacking hydrogen bonds.
This results in significantly high values for the enthalpy of vaporization in compounds characterized by hydrogen bonds (such as hydrogen halides).
Thus, this leads to option D being the correct choice among the provided answers. The enthalpy of vaporization serves as the most reliable indicator of the relative strength of hydrogen bonds.
a) The completely balanced chemical reaction is:
Zn(s) + H2SO4(aq)
--------> ZnSO4(aq) + H2 (g)
<span>b) Initially, we determine the quantity of zinc that has reacted based on the produced H2.</span>
According to stoichiometry, 1 mole of Zn is required for each mole of H2 created, thus:
moles(Zn) = moles(H2)
where moles are calculated as the ratio of mass to molar mass (MM)
mass(Zn) / MM(Zn) = mass(H2) / MM(H2)
mass(Zn) = [mass(H2) / MM(H2)] * MM(Zn)
mass(Zn) = [(0.0764 g)/(2 g/mol)] * 65.38 g/mol
mass(Zn) = 2.49 g
Consequently, we find 2.49 g of pure zinc in the sample, leading to a purity of zinc of:
purity = (2.49 / 3.86) * 100 % = 64.50 %
<span>c) In part (b), it is assumed that the impurities in the sample do not react with sulfuric acid to emit hydrogen.
Thus, the hydrogen solely arises from the reaction of Zn with sulfuric acid.</span>
