Answer:
C
Explanation:
It afffects changes in pressure and temperature not melting and boiling points
Answer: Rate of decomposition of acetaldehyde in a solution is 
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
For a reaction : 
![Rate=k[A]^x](https://tex.z-dn.net/?f=Rate%3Dk%5BA%5D%5Ex)
k= rate constant
x = order of the reaction = 2


Thus rate of decomposition of acetaldehyde in a solution is
I believe the correct answer is D. Because object A on the pH scale reads pH=3. Which means it is more acidic in nature and thus possess a greater hydrogen or hydronium ion concentration than object B, which has a higher value on the pH scale. Object B would thus have a lower hydronium ion concentration than Object A.
Ionic bonding is formed in Ionic compounds due to electrostatic force between the oppositely charged ions.
In covalent bonds electrons are shared between the atoms. In case of ionic bond the bond is stronger as there is complete transfer of electrons from one ion to the other.
Since the ionic bonds are more difficult to break than the covalent bonds, ionic compounds have a higher melting point than covalent compounds.