By being an alternative route to the reaction with a lower activation energy.
Answer:
Chemical change.
Explanation:
When it is heated it decomposes into mercury and oxygen gas. The mercury oxide reactant becomes the silver color of mercury. Hence, a color change can be noticed throughout the reaction.
Answer: 
Explanation:
a) 
: This is a non polar covalent compound which are held by weak vanderwaal forces of attraction.
b) 
: This is a covalent compound which is polar due to the presence of lone pair of electrons and are held by dipole-dipole forces of attraction.
c) : These are joined by a special type of dipole dipole attraction called as hydrogen bond. It forms between electronegative nitrogen atom and hydrogen atom and is the strongest interaction.
d) 
: This is a covalent compound and is non polar which are held by weak vanderwaal forces of attraction.
e) 
: This is a covalent compound and is non polar which are held by weak vander waal forces of attraction.
<span>100,000 times more. The rule is that the product of the concentration of (H+) and (OH-) in molars is always 10^-14 (if it is more, they combine and produce simple water which brings the product back down to this number again. If it is less, water molecules will split to bring the product back up to equilibrium).
pH 9 means (H+) is 10^-9 molar. But that means (OH-) is 10^-5 at the same time.
pH 4 means (H+) is 10^-4 molar. But that means (OH-) is 10^-10 at the same time.
10^-5 / 10^-10 = 10^5 or 100,000 times more.</span>
