Answer:
3 > 2> 1
Explanation:
Aromatic compounds undergo electrophilic substitution reaction which passes through a positively charged intermediate to yield the product.
Substituted benzenes may be more or less reactive towards electrophilic aromatic substitution than benzene molecule depending on the nature of the substituent.
Certain substituents increase the ease of reaction of benzene towards aromatic substitution.
If we look at the compounds closely, we will notice that toluene reacts readily with CH3Cl / AlCl3. This is because, the methyl group is electron donating hence it stabilizes the positively charged intermediate produced in the reaction.
Carbonyl compounds are electron withdrawing substituents hence they decrease the magnitude of the positive charge and hence decrease the rate of electrophilic aromatic substitution.
Answer:
The quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
Explanation:
Latent heat of fusion is the heat absorbed by a unit mass of a given solid at its melting point that completely converts the solid to a liquid at the same temperature. Its unit is Joules/kg or Joules/g.
1 calorie = 4.184 Joules
Therefore , 80.0 cal/g = 80.0 cal/g * 4.184 J/cal = 334.72 J/g
1 g = 0.001 kg; Heat of fusion in J/kg = 334.72 J/g * 1g /0.001 kg = 3.35 * 10⁵ J/kg
Quantity of heat, Q = mass * latent heat of fusion of ice
quantity of heat required = 6.60 kg * 3.35 * 10⁵ J/kg
Quantity of heat required = 2.21 * 10⁶ J
Therefore, the quantity of heat required to melt all the ice at 0°C is 2.21 * 10⁶ J
The Calcium ion is an Alkaline earth metal and wants to give up the 2 s orbital elections and become a +2 cation.
Oxygen has six valence electrons and is looking to gain two electrons to complete the octet (8) electron count in the valence shell making it a -2 anion.
When the charges of the Calcium +2 and the Oxygen -2 are equal and opposite, the ions for an electrical attraction. (Remember Paula Abdul told us "Opposites Attract")
This one to one ratio of charges makes the formula CaO
Given parameters:
Heat of fusion of water = 334j/g
Mass of ice = 45g
Temperature of ice = 0.0°c
Unknown:
Amount of heat needed to melt = ?
Solution:
This is simply a phase change and a latent heat is required in this process.
To solve this problem; use the mathematical expression below;
H = mL
where m is the mass
L is the heat of fusion of water;
H = 45 x 334 = 15030J
