D water is hotter than ice.
Answer:
Explanation:
Heat of vaporization is the amount of heat required to convert 1 mole of liquid substance to its vapor form.
Given :
Amount of heat required for 1 mol of water = 40.7 kJ/mol
According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number of particles.
1 mole of weighs = 18.02 g
Thus we can say:
18.02 g of requires heat = 40.7 kJ
Thus 5.6 g of requires heat = (1kJ=1000J)
Thus the energy required to completely vaporize 5.6 g of water at 100.°C is
The <span>henderson-hasselbalck equation is this
pH = pK + log [salt]/[acid]
We are given with
pH = 4.00
</span><span>1.50 l of 0.0200 m solution of benzoic acid
The pK for benzoic acid is
4.20
Solving for the moles of salt,
4 = 4.2 + log 1.5(0.02)/n
n = 71.62 moles
The mass is
m = 71.62 (249.2)
m = 17800 grams</span>
Answer:
3.18x10⁻³
Explanation:
The equilibrium of a weak acid can be written as:
And Ka can be expressed as:
- Ka=
<u><em>Keep in mind that [H⁺] = [A⁻]</em></u>.
We can<u> calculate [H⁺] from the pH</u>:
- [H⁺]==0.0158
Now we <u>compute the calculated [H⁺]</u> (and [A⁻]) <u>with the [HA] given by the problem</u>:
Ka = = 3.18x10⁻³
Answer:
Nitrobenzene < Bromobenzene < Benzene < Phenol
Explanation:
Aromatic compounds undergo electrophilic aromatic substitution reaction in the presence of relevant electrophiles. Certain substituents tend to increase or decrease the tendency of an aromatic compound towards electrophilic aromatic substitution reaction.
Substituents that increase the electron density around the ring such as in phenol tends to make the ring more reactive towards electrophilic substitution. Halogens such as bromine has a -I inductive effect as well as a +M mesomeric effect.
However the -I(electron withdrawing effect) of the halogens supersedes the +M electron donation due to mesomeric effect.
Putting all these together, the order of increasing reactivity of the compounds towards electrophilic aromatic substitution is;
Nitrobenzene < Bromobenzene < Benzene < Phenol