Notes, summaries, assignments, exams, and problems for Baccalaureate

The Mole Concept

The mole concept is an International System unit of measurement for a substance. It is also represented by carbon-12, and 1 mole is equal to Avogadro's number (6.022 x 10^23).

The Periodic Table's Role in Stoichiometric Calculations

We use the periodic table to get values for given elements in a reaction to obtain their atomic values. We can then use these values for conversion from grams to moles or moles to grams in stoichiometric-based problems (gram/mole, mole-gram conversions).

Heat vs. Enthalpy

Heat is the energy that flows between a system and its surroundings due to a difference in temperature.

Enthalpy is equivalent to the total heat content of a system.

Why Only Enthalpy Explains Energy Associated with Chemical Bonds

Because... Continue reading "Principles of Chemistry: From Stoichiometry to Molecular Orbital Theory" »

Letters Giving Advice

Introduction

Paragraph 1 - Thanks for the letter and express understanding of the problem.

Main Body

Paragraphs 2, (3) - Suggestion(s) and reason(s).

Conclusion

Final paragraph - Closing remarks.

Useful Language for Letters Giving Advice

Opening Remarks

Formal

• Thank you for your letter requesting...
• I am writing in reply to your letter asking for advice about...
• I hope the following advice will be of some help to you, etc.

Informal

• I just got your letter and I think I can help you...
• I was sorry to hear about your problem. Here's what I think you should do, etc.

Suggestions

Suggestions can be introduced with expressions such as:

Formal

• I strongly recommend that...
• I would suggest that...
• I believe the best course of action is...
• I would advise

The Cold War: Definition and Origins

The Cold War was the most important political issue of the early post-war period. It originated from long-lasting disagreements between the Soviet Union and the United States regarding their political and economic ideologies.

The Western Bloc defended a liberal democratic political regime within a capitalist economy, where corporations were the beneficiaries. The Soviet Union and its allies defended a form of state socialism. In reality, this system often resulted in a group of dictatorships within a state-based economic system where the hierarchy of the sole party, the Communist Party, became the new dominant class.

Key Events Triggering the Cold War

1. The Abandonment of US Isolationism: The Truman Doctrine.

What Was World War II?

World War II, a global armed conflict lasting from 1939 to 1945, was a total war in two distinct aspects. Firstly, civilian populations became primary targets and the war's most tragic victims. Secondly, the conflict engulfed all continents, marking it as one of the most brutal and inhumane wars in history.

Driven by Nazi expansionism, World War II represented an ideological struggle. It pitted democracy and socialism against fascism, even sparking civil conflicts within the Axis powers—Germany, Italy, and Japan. The Allied forces—including Britain, France, the USA, and the Soviet Union—fought for liberal democratic principles.

As the largest armed conflict in human history, World War II resulted in unprecedented destruction,... Continue reading "World War II: Causes, Impact, and Legacy" »

Verb Tenses

Conditionals

Passive