D.The transferring of thermal energy from the sun to the earth!
Answer : The change in internal energy is, 900 Joules.
Solution : Given,
Heat given to the system = +1400 J
Work done by the system = -500 J
Change in internal energy is equal to the sum of heat energy and work done.
Formula used :

where,
= change in internal energy
q = heat energy
w = work done
As per question, heat is added to the system that means, q is positive and work done by the system that means, w is negative.
Now put all the given values in the above formula, we get

Therefore, the change in internal energy is 900 J.
The change in internal energy depends on the heat energy and work done. As we will change in the heat energy and work done, then changes will occur in the internal energy. Hence, the energy is conserved.
Answer : The pH of buffer is 9.06.
Explanation : Given,

Concentration of HBrO = 0.34 M
Concentration of KBrO = 0.89 M
Now we have to calculate the pH of buffer.
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[KBrO]}{[HBrO]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BKBrO%5D%7D%7B%5BHBrO%5D%7D)
Now put all the given values in this expression, we get:


Therefore, the pH of buffer is 9.06.
Answer:
Polyester
Acrylic
Nylon
Are all made of fossil fuels.