Answer:
4
Explanation:
The following equation, which depicts the combustion of propane, is given in this question as follows:
C3H8 + 02 → CO2 + H2O
However, this equation is not yet BALANCED because the number of atoms of each element is not the same on the reactant and product side. To balance the equation, we make use of COEFFICIENT to ensure that the number of atoms of each element on both side correlates.
The balanced equation is as follows:
C3H8 + 502 → 3CO2 + 4H2O
Therefore, the coefficient for water (H2O) after balancing the equation is 4.
2-bromo-1-chloro-4-nitrobenzene is being synthesized in following sequence:
Step 1: Chlorination of Benzene:
This is Halogenation reaction of benzene. In this step benzene is reacted with Chlorine gas in the presence of lewis acid (i.e. FeCl₃). This results in the formation of Chlorobenzene as shown in red step below.
Step 2: Nitration of Chlorobenzene:
The chlorine atom on benzene has a ortho para directing effect. Therefore, the nitration of chlorobenzene will yield para nitro chlorobenzene as shown in blue step below.
Step 3: Bromination of 1-chloro-4-nitrobenzene:
In this step bromination is done by reacting bromine in the presence of lewis acid. The chlorine being ortho para directing in nature and nitro group being meta directing in nature will direct the incoming Br⁺ (electrophile) to the desired location. Hence, 2-bromo-1-chloro-4-nitrobenzene is synthesized in good yield.
Chemical should be the answer hope I helped
If you had a specific equation it would help you get a bigger picture.
Basics of balancing equations is making sure you have both sides of the equation, that is reactants and products.
This helps you to know where the oxidation and reduction happened so you can figure out which elements gained or lost electrons and by how much.
Then look and molecules and compounds individually and as a whole, so that you can accurately account for the balance.
Then you have to do alot of practice.
Take up quizes in your free time and the more exposure you have, the better you will familiarize yourself with what to and not to do.
(Send an example for more explanation)