Answer:
B. Atoms in the original substances are arranged in a different way to make new substances.
Explanation:
The best statement that describes a change that occurs in a chemical reaction is that atoms in the original substances are arranged in a different way to make new substances.
- Chemical reactions obey the law of conservation of matter.
- The law postulates that "matter is neither created nor destroyed in a chemical reaction but they are simply rearranged".
- Therefore, atoms of compounds forms new bonds by rearranging to give a new product.
Dozen = 12,
ii. 1 score = 20
iii. 1 ream = 500
iv. 1 gross = 1.44
Answer:
Equilibrium concentrations of the gases are



Explanation:
We are given that for the equilibrium

Temperature, 
Initial concentration of



We have to find the equilibrium concentration of gases.
After certain time
2x number of moles of reactant reduced and form product
Concentration of



At equilibrium
Equilibrium constant
![K_c=\frac{product}{Reactant}=\frac{[H_2]^2[S_2]}{[H_2S]^2}](https://tex.z-dn.net/?f=K_c%3D%5Cfrac%7Bproduct%7D%7BReactant%7D%3D%5Cfrac%7B%5BH_2%5D%5E2%5BS_2%5D%7D%7B%5BH_2S%5D%5E2%7D)
Substitute the values



By solving we get

Now, equilibrium concentration of gases


