The main reason for the difference in boiling points between methanal (formaldehyde) and ethanal (acetaldehyde) is the difference in molecular weight and size. Ethanal has a larger molecular size and weight compared to methanal, which leads to stronger intermolecular forces such as van der Waals forces, resulting in a higher boiling point for ethanal.
The main reason for grounding the outer shell of an electric fixture is to prevent electric shock in case of a fault within the fixture. Grounding directs any excess electricity to the ground, keeping the outer shell safe and reducing the risk of electric shock to anyone touching it.
An ad and an article are for different reasons. An ad is to put
out what a company does to get more costumers. An article is to
inform people of the world whats going on at the time.
You can say that you are ready to move ahead in your career. You
can tell them that you offer professionalism, determination, strong
skills and good customer service.
The main reason for the expedition was to explore and discover new lands, resources, and trade routes. It was also driven by a desire for wealth, power, and prestige for the sponsoring country or organization.
The main reason for World War I was the system of protection
treaties that were inacted by European countries before the war.
When Archduke Ferdinand was murdered by a Serbian nationalist in
Sarajevo, the Austrians presented extraordinary demands on Serbia
that the Serbs had no choice but to refuse. When Austria resolved
to attack Serbia, the treaties demanded that some of the
signatories defend Serbia. Still other countries were required to
defend Austria. This created a chain reaction that started this
horrible war.