Answer:
the answer is D
Explanation:
the reason how ik this is that i already did this test so yea
You’re answer would be B love!
C2H6O + 3O2 —> 2CO2 + 3H2O
In this reaction 50% of the compound decompose in 10.5 min thus, it is half life of the reaction and denoted by symbol 
.
(a) For first order reaction, rate constant and half life time are related to each other as follows:
Thus, rate constant of the reaction is 
.
(b) Rate equation for first order reaction is as follows:
![k=\frac{2.303}{t_{1/2}}log\frac{[A_{0}]}{[A_{t}]}](https://tex.z-dn.net/?f=k%3D%5Cfrac%7B2.303%7D%7Bt_%7B1%2F2%7D%7Dlog%5Cfrac%7B%5BA_%7B0%7D%5D%7D%7B%5BA_%7Bt%7D%5D%7D)
now, 75% of the compound is decomposed, if initial concentration ![[A_{0} ]](https://tex.z-dn.net/?f=%5BA_%7B0%7D%20%5D)
is 100 then concentration at time t ![[A_{t} ]](https://tex.z-dn.net/?f=%5BA_%7Bt%7D%20%5D)
will be 100-75=25.
Putting the values,
On rearranging,
Thus, time required for 75% decomposition is 21 min.
Surface tension is the result of water molecules pulling inward with a strong attractive force.
The attractive force brings the molecules on the surface of the water close together.
The attractive force causes the surface of the water to be drawn toward the water molecules beneath the surface. <span>
Since there are no water molecules above the surface, there are uneven forces. This causes surface tension, allowing the coin to float on the water’s surface.</span>
