Answer : The excess reactant in the combustion of methane in opem atmosphere is
molecule.
Solution : Given,
Mass of methane = 23 g
Molar mass of methane = 16.04 g/mole
The Net balanced chemical reaction for combustion of methane is,

First we have to calculate the moles of methane.
=
= 1.434 moles
From the above chemical reaction, we conclude that
1 mole of methane react with the 2 moles of oxygen
and 1.434 moles of methane react to give
moles of oxygen
The Moles of oxygen = 2.868 moles
Now we conclude that the moles of oxygen are more than the moles of methane.
Therefore, the excess reactant in the combustion of methane in open atmosphere is
molecule.
Answer: to find a cure for the common cold to produce insulin for diabetics
Explanation: It has helped many people
Answer:
Option B: ΔH is (+); endothermic
Explanation:
From the reaction Cl2 → 2Cl(g) given, we can see that the number of moles on the left hand side is 1 while on right hand side, it is 2. This means the number of moles are increasing and it means that the randomness of the system has increased. Also, the bonds are being broken down.
Therefore, the reaction is endothermic. In endothermic reactions, ΔH is positive.
Thus, the correct option is option B.