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).
You should always do A. form a hypothesis before performing an experiment also the other options cannot happen until after an experiment.
Answer
find out the number of moles and use the molar ratio (numbers in front of formulas (in this case they are all 1) to determine how many moles of each product you are going to get theoretically
n=m/M is the equation to use to get moles here
30.8 gm/32.04 g/mol=0.9612 moles of the methanol and also of the formaldehyde so
0.9612 moles of the formaldehyde x molar mass (M) 30.73 g/mol= 29.54 gm which is the theoretical yield you already have the actual yield of 24.7 gm
then divide the actual by the theoretical to get the % yield which is 83.6%
Explanation:
