Compound A is Ethylbenzene.
<h3>Explanation:</h3>The structure of Ethylbenzene was elucidated and finalized based on following facts:
1) The presence of multiplet signal ranging from δ 7.27 to 7.40 ppm confirms the presence of aromatic protons. Also the statement says that this signal is for 5 protons indicating that the benzene ring is mono substituted.
2) The substituted group on benzene is Ethyl because the quartet for two protons shows that two protons (-CH₂-) are coupled with a CH₃ group. Hence, the ethyl group gives one quartet and one triplet signal.
3) The chemical reaction stated in statement is Nitration reaction. Also, the alkyl group (ethyl) is ortho-para directing in nature. Hence, it will give two products i.e. 1-Ethyl-2-nitrobenzene and 1-Ethyl-4-nitrobenzene respectively.
Attached figure gives the calculated NMR spectrum of Ethylbenzene and the chemical shifts calculated are almost near to the given values. Also, the two products formed are shown.
Answer: The concentration of will be
after 416 seconds have passed.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant =
t = age of sample = ?
a = let initial amount of the reactant =
a - x = amount left after decay process =
The concentration of will be
after 416 seconds have passed.
Taking into account the definition of molarity, the molarity of a solution prepared by dissolving 0.2 mol sucrose in enough water to make a 100 mL solution is 2 .
Molar concentration or molarity is a measure of the concentration of a solute in a solution and indicates the number of moles of solute that are dissolved in a given volume.
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution:
Molarity is expressed in units .
In this case, you have:
Replacing in the definition of molarity:
Solving:
<u><em>molarity= 2 </em></u>
Finally, the molarity of a solution prepared by dissolving 0.2 mol sucrose in enough water to make a 100 mL solution is 2 .
Learn more about molarity: