Answer:
You never listed the options
Explanation:
A chemical reaction is a process that involves rearrangement of the molecular or ionic structure of a substance, as opposed to a change in physical form or a nuclear reaction.
Given :
Some compounds :
.
To Find :
Which of the following compounds has the most deshielded protons .
Solution :
Deshielded means nucleus whose chemical shift has been increased due to removal of electron density, magnetic induction, or other effects .
In simple words deshielding means the ability to shift protons .
Now , among Cl , I , Br and H . Cl is the most electron negative .
Therefore , deshielding will be more in 
.
Hence , this is the required solution .
Answer:
0.0055 mol of N2O5 will remay after 7 min.
Explanation:
The reaction follows a first-order.
Let the concentration of N2O5 after 7 min be y
Rate = Ky = change in concentration of N2O5/time
K is rate constant = 6.82×10^-3 s^-1
Initial concentration of N2O5 = number of moles/volume = 2.1×10^-2/1.8 = 0.0117 M
Change in concentration = 0.0117 - y
Time = 7 min = 7×60 = 420 s
6.82×10^-3y = 0.0117 - y/420
0.0117 - y = 420×6.82×10^-3y
0.0117 - y = 2.8644y
0.0117 = 2.8644y + y
0.0117 = 3.8644y
y = 0.0117/3.8644 = 0.00303 M
Number of moles of N2O5 left = y × volume = 0.00303 × 1.8 = 0.0055 mol (to 2 significant digits)
