Compound b (c9h9no4) is a carboxylic acid that has a nitro group attached to an aromatic ring. draw this compound based on its 1
h nmr spectrum.
1 answer:
The NMR is attached that is required to answer this question. We are told that we have a carboxylic acid and that there is a nitro group directly attached to an aromatic ring. We can begin by determining the substitution on the aromatic ring.
Looking at the NMR spectrum, we a peak that integrates to 1 H at 12 ppm which is characteristic of a carboxylic acid, which we already know is present. Next we have two equivalent doublets that both integrate to 2 H, giving us 4 hydrogens in total. These doublets are in the aromatic region and this type of coupling pattern is characteristic of a 1,4-substituted aromatic ring, so we know there is only one other group substituted on the ring. However, the molecular formula is C₉H₉NO₄, so there are still 2 carbons not accounted for, if we include our carboxlic acid. Therefore, the carboxylic acid must be attached to some alkyl group which is substituted onto the aromatic ring.
We have a doublet at 1.6 ppm that integrates to 3, which suggests this is a methyl group adjacent to a CH. We also have a quartet at 4.0 ppm with an integration of 1. This suggests it is a CH that is adjacent to 3 hydrogen, most likely the methyl group we just described.
Therefore, we have a CH attached to a CH3, so that CH requires two more bonds. The only pieces left to attach to it are the aromatic ring and the carboxylic acid functional group. This gives us the structure shown in the image provided.
Looking at the NMR spectrum, we a peak that integrates to 1 H at 12 ppm which is characteristic of a carboxylic acid, which we already know is present. Next we have two equivalent doublets that both integrate to 2 H, giving us 4 hydrogens in total. These doublets are in the aromatic region and this type of coupling pattern is characteristic of a 1,4-substituted aromatic ring, so we know there is only one other group substituted on the ring. However, the molecular formula is C₉H₉NO₄, so there are still 2 carbons not accounted for, if we include our carboxlic acid. Therefore, the carboxylic acid must be attached to some alkyl group which is substituted onto the aromatic ring.
We have a doublet at 1.6 ppm that integrates to 3, which suggests this is a methyl group adjacent to a CH. We also have a quartet at 4.0 ppm with an integration of 1. This suggests it is a CH that is adjacent to 3 hydrogen, most likely the methyl group we just described.
Therefore, we have a CH attached to a CH3, so that CH requires two more bonds. The only pieces left to attach to it are the aromatic ring and the carboxylic acid functional group. This gives us the structure shown in the image provided.
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Answer:
0.00369 moles of HCl react with carbonate.
Explanation:
Number of moles of HCl present initially = moles = 0.00600 moles
Neutralization reaction (back titration):
According to above equation, 1 mol of NaOH reacts with 1 mol of 1 mol of HCl.
So, excess number of moles of HCl present = number of NaOH added for back titration = moles = 0.00231 moles
So, mole of HCl reacts with carbonate = (Number of moles of HCl present initially) - (excess number of moles of HCl present) = (0.00600 - 0.00231) moles = 0.00369 moles
Hence, 0.00369 moles of HCl react with carbonate.
Answer: a) : negative
b) : positive
c) : positive.
d) : negative
e) : positive.
f) : positive.
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
is positive when randomness increases and
is negative when randomness decreases.
a)
As ions are moving to solid form , randomness decreases and thus sign of is negative.
b)
As solid is changing to gas, randomness increases and thus sign of is positive.
c)
As 2 moles of reactants are converted to 4 moles of products , randomness increases and thus sign of is positive.
d)
As gas is changing to solid, randomness decreases and thus sign of is negative.
e)
As 7 moles of reactants are converted to 8 moles of products , randomness increases and thus sign of is positive.
f)
As solid is changing to gas, randomness increases and thus sign of is positive.