Answer: Mothballs have weak intermolecular forces.
No all substances do not behave like mothballs at normal conditions. Example: benzene , chloroform
Explanation:
Sublimation is a process of converting a substance from solid state to gaseous state without the formation of liquid at constant temperature.
A substance which undergoes sublimation is called as sublimating substance.
As mothballs is made of napthalene which has weak inter molecular forces of attraction between its molecules, it directly sublimes into gaseous state without leaving any residue and is called as a sublimating substance.
Not all substances behave like mothballs at normal conditions. Example: benzene , chloroform
I definitely agree whithe the first person that the earths orbit brings that part closer to the sun
From the equation; ΔTf = Kf × m
Where, Kf for water = 1.853 K kg/mole; m is the molarity = number of solute/amount of solvent in kg.
Glucose is the solute whose molecular mass is 180 g/mole and water is the solvent.
Moles of solute = 15.5/180 = 0.0861 moles
Amount of solvent in kg = 245/1000 = 0.245 Kg
Therefore; molarity = 0.0861/0.245 = 0.3515 moles/Kg
Therefore; ΔTf = 1.853 × 0.3515 = 0.6513 K
Hence; the depression in freezing point is 0.6513
The freezing point of solution will therefore be;
= 273 - 0.6513 = 272.3487 K
Answer:
Explanation:
Public tap water is not desirable when carrying out experiments in the laboratory.
The chemical definition of water is a compound made up of two atoms of hydrogen to 1 atom of oxygen. Any violation simply desist from the true meaning of water.
Why are tap water not used:
- They contain other dissolved ions like chlorine which have been added in their treatment. This alters the fundamental molecules that is expected to be seen in water. Water of this nature can affect experimental results seriously.
- Tap water can become a mixture instead of a simple compound. A mixture is a combination of several compounds. Such water will have a varied composition and make simplification of experiments very difficult.
<span>The composition of a fertilizer is usually express in NPK number. NPK number is in terms of Percent by mass of the said element which are Nitrogen, Phosphorus and Potassium. A 15-35-15 fertilizer has 15%
Nitrogen, 35% Phosphorous, and 15% Potassium by mass. If you have 10 g of this
fertilizer, to get the number of moles of phosphorus, you multiply the mass by
35%, which is equal to 10*0.35 or 3.5 g phosphorus. Then you divide the
calculated mass of phosphorous by its molar mass which is 30.97 g/mol.
Therefore, you have 3.5/30.97 which is equal to 0.1130 mol Phosphorus. This is the amount of Phosphorus in moles in the fertilizer.</span>
