Answer: 3.5 moles of hydrogen gas will be produced.
Explanation:
The balanced chemical equation is:

As HCl gets completely used up,
is the limiting reagent.
According to stoichiometry :
6 moles of
produces = 3 moles of
Thus 7.0 moles of
produces=
of
Thus 3.5 moles of hydrogen gas will be produced.
Answer:
Paraffin oil is used for determination of boiling point and melting point for the following reasons: It has a very high boiling point and so it can be used to maintain high temperatures in the boiling and melting point apparatus without loss of the substance.
Answer : The correct option is, (D)
Explanation :
Option A reaction : 
It is a combustion reaction. A reaction in which a hydrocarbon react with the oxygen to give product as carbon dioxide and water.
Option B reaction : 
It is a combination reaction. A reaction in which the two or more reactants react to give a product.
Option C reaction : 
It is a decomposition reaction. A reaction in which a reactant decomposes to form two or more products.
Option D reaction : 
It is a single displacement reaction. It is a reaction in which the more reactive element displace the less reactive element. In this reaction, most reactive element chlorine displaces the less reactive element bromine.
Hence, the correct option is, (D)
Answer:
Condensation
Explanation:
An exothermic process is one in which heat is lost. Condensation is a change of state from gas to liquid. Thus is loses heat.
HOPE THIS HELPED
Be-beryllium have 2 electrons and it is in the 2 nd period