ΔH<span> for the reaction = [sum of heat of formation for products] - [sum of heat of formation for reactants]
-6534 = [(12)(-393.5) + (6)(-285.8)] - (2X)
-6534 = [(-4722) + (-1714.8)] - 2X
-6534 = -6436.8 - 2X
-6534 + 6436.8 = -2X
-</span>97.2 = -2X<span>
then, divide each side by two to cancel out the numerical coefficient.
x = +48.6 kJ, which is the heat of formation for benzene.</span>
Answer:
<u>Principal</u><u> </u><u>focus</u><u> </u><u>of</u><u> </u><u>concav</u><u>e</u><u> </u><u>lens</u><u> </u><u>-</u><u> </u>
★ The point at which rays parallel to principal axis coming from infinity appear to converge after being refracted from concave lens is called the principal focus of concave lens.
<em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em><em><u>_</u></em>
• <u>Additional</u><u> information</u><u> </u><u>-</u><u> </u>
★ Principal focus - A number of rays parallel to the principal axis after reflection from a concave mirror meet at a point on the principal axis or appear to come from a point after reflection from a convex mirror on the principal axis. This is called principal focus.
As the greater force of tension (by 81N) is exerted by the team on the right the rope will move to the right.
The force of earth's gravitational field is always directed downwards (towards the center of the earth. When the ball is thrown up, it is going against the earth's gravitational field and so, the earth's gravitational force pulls it back down, accelerating it downwards.
A proton is held at rest in a uniform electric field. When it is released, the proton will lose its kinetic energy.
Kinetic energy
The energy an object has as a result of motion is known as kinetic energy in physics. It is described as the effort required to move a mass-determined body from rest to the indicated velocity. The body holds onto the kinetic energy it acquired during its acceleration until its speed changes. The body exerts the same amount of effort when slowing down from its current pace to a condition of rest. Formally, kinetic energy is any term that includes a derivative with respect to time in the Lagrangian of a system.
To learn more about kinetic energy refer here:
brainly.com/question/11301578
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