For the very last question you would first divide 8,900 by 12 and the number you get will be the answer. You should get 741.66
Answer is: the combined ionic bond strength of CrCl₂ and intermolecular forces between water molecules.
When chromium chloride (CrCl₂) is dissolved in water, the temperature of the water increases, heat of the solution is endothermic.
Dissociation of chromium chloride in water: CrCl₂(aq) → Cr²⁺(aq) + 2Cl⁻(aq).
Energy (the lattice energy) is required to pull apart the oppositely charged ions in chromium chloride.
The heat of hydration is liberated energy when the separated ions (in this example chromium cations and chlorine anions) attract polar water molecules.
Because the lattice energy is higher than the heat of the hydration (endothermic reaction), we can conclude that bonds between ions are strong (the electrostatic attraction between oppositely charged ions).
Let MM(x) be the molar mass of x.
MM(Pb) : MM(PbO)
=207.21 : 223.20 = 451.4 g : x g
cross multiply and solve for x
x=223.2/207.21*451.4
= 486.23 g
Percentage yield = 365.0/486.23= 0.75067 = 75.07% (rounded to 4 sign. fig.)
As the atomic radius decreases, it becomes harder to remove an electron that is closer to a more positively charged nucleus. ... They experience a weaker attraction to the positive charge of the nucleus. Ionization energy increases from left to right in a period and decreases from top to bottom in a group.
Cirrhosis is a disease that affects the liver