The answer is carbonic acid
The answer is TRUE.
If the Energy is on the left, then the problem is true. If it is on the right then it would be negative, false, and considered as exothermic.
Endothermic reaction = the products are higher in energy than the reactants.
Exothermic reaction = a chemical reaction that releases energy by light or heat.
A substance undergoing thermal expansion will expand when heated, substances will mostly expand when heated but when their cold it will undergo contraction.
Answer: a. 0.75m (NH4)3PO4 will have the lowest freezing point .
Explanation: Freezing point decreases as the concentration of the solute substance increases. Assuming the same solvent for all of them, for instance water.
∆T= i.Kf.b
∆T= freezing point depression
i= vant Hoff factor
Kf= molality
Assuming water to be the solvent for all Kf=1.86°C/M
VANT HOFF FACTORS :
For (NH4)3PO4
This has 3 ionic bonding and 1 covalent bonding making it 4 bond
Therefore i=4
For CaSO4
This has 1 metallic bond and 1 covalent bond making it 2 bond.
Therefore i=2
For LiCl
This has 1 metallic bond and 1 non metallic bond making it 2 bond.
Therefore i=2
For CH3OH
This has only 1 covalent bond.
Therefore i=1
MOLALITY:
(NH4)3PO4 = 0.75M
CaSO4= 1.0M
LiCl= 1.0M
CH3OH= 1.5M
FREEZING POINT DEPRESSION:
For (NH4)3PO4
∆T= 4×0.75×1.86=5.58°C
For CaSO4
∆T= 2×1.0×1.86=3.72°C
For LiCl
∆T = 2×1.0×1.86= 3.72°C
For CH3OH
∆T= 1×1.5×1.86=2.79°C
REMEMBER THE HIGHER THE FREEZING POINT DEPRESSION THE LOWER THE FREEZING POINT.
FREEZING POINT DEPRESSION IS THE CHANGE IN THE FREEZING POINT PROPORTIONAL TO THE AMOUNT OF SOLUTE ADDED THE THE SOLUTION.
THEREFORE THE ONE WITH THE LOWEST FREEZING POINT IS (NH4)3PO4
Explanation:
Element Symbol Mass Percent
Calcium Ca 38.763%
Oxygen O 41.265%
Phosphorus P 19.972%
