Answer:
d) cut the large sized Cu solid into smaller sized pieces
Explanation:
The aim of the question is to select the right condition for that would increases the rate of the reaction.
a) use a large sized piece of the solid Cu
This option is wrong. Reducing the surface area decreases the reaction rate.
b) lower the initial temperature below 25 °C for the liquid reactant, HNO3
Hugher temperatures leads to faster reactions hence this option is wrong.
c) use a 0.5 M HNO3 instead of 2.0 M HNO3
Higher concentration leads to increased rate of reaction. Hence this option is wrong.
d) cut the large sized Cu solid into smaller sized pieces
This leads to an increased surface area of the reactants, which leads to an increased rate of the reaction. This is the correct option.
Answer:
C. 
Explanation:
Molecules with the stronger intermolecular forces are pulled tightly together to form solid at higher temperatures and that's why the freezing point is higher.
Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.
Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).
Thus, the compound which is gas at room temperature is
<u>because it has least number of carbon atoms and absence of hydrogen bonding.</u>
<u></u>
<u>Answer:</u> The conjugate acid of
is 
<u>Explanation:</u>
According to the Bronsted-Lowry conjugate acid-base theory:
- An acid is defined as a substance which looses donates protons and thus forming conjugate base.
- A base is defined as a substance which accepts protons and thus forming conjugate acid.
To form a conjugate acid of
, this compound will accept one proton to form 
The chemical equation for the formation of conjugate acid follows:

The conjugate acid formed is named as carbonic acid.
Hence, the conjugate acid of
is 