If a system's internal energy increases by 250 kJ after the addition of375 kJ of energy as heat, what was the value ofthe work in the process? (A) -625 kJ
(B) -125 kJ
(C) 125 kJ
(D) 625 kJ

(B) -125 kJ

Explanation:

Going by the First Law of Thermodynamics it states that"

"A system can do work and increase it's internal energy provided we supply heat."

ΔU= q+w1

where U= the internal heat

           q= the quantity of heat added or removed from the system

            w= the work done

Given

ΔU= 250kJ

q= 375kJ

from equation 1 make w subject of the formula we have

w= ΔU-q

w= 250-350

w= -125kJ

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.