Chemical Reactions and Equations

These flashcards cover key concepts from the lecture on chemical reactions and equations.

What occurs when a magnesium ribbon is burnt in air?

It gets converted to magnesium oxide.

What indicates that a chemical change has taken place?

Signs include change in state, change in colour, evolution of a gas, and change in temperature.

What is a word-equation for burning magnesium in oxygen?

Magnesium + Oxygen → Magnesium oxide.

What is a skeletal chemical equation for the reaction of magnesium and oxygen?

Mg + O2 → MgO.

What is necessary for a chemical equation to be considered balanced?

The number of atoms of each element must be the same on both reactants and products sides.

What type of reaction occurs when two or more substances combine to form a single product?

Combination reaction.

How can you identify an exothermic reaction?

These reactions release heat along with the formation of products.

What happens during a displacement reaction?

One element removes another element from its compound.

Give an example of a double displacement reaction.

Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq).

What does corrosion refer to in terms of chemical reactions?

Corrosion is the process where metals, like iron, get damaged due to reactions with moisture and acids, commonly leading to rust.

What is the difference between oxidation and reduction in a chemical reaction?

Oxidation refers to the gain of oxygen or loss of hydrogen, while reduction is the loss of oxygen or gain of hydrogen.

What is a precipitation reaction?

A reaction that produces an insoluble substance, known as a precipitate.

How is respiration classified in terms of chemical reactions?

Respiration is an exothermic process as it releases energy.

What symbol indicates a gaseous substance in a chemical equation?

The symbol (g) is used to denote a gas.

What is meant by a thermal decomposition reaction?

When a single substance breaks down into two or more substances upon heating.

What is evaporation?

Evaporation is the process by which water changes from a liquid to a gas, usually due to heat.

What is condensation in the water cycle?

Condensation is the process by which water vapor cools and changes back into liquid form, forming clouds.

What is precipitation?

Precipitation is any form of water, such as rain or snow, that falls from clouds to the earth.

What is collection in the water cycle?

Collection refers to the gathering of water in bodies like rivers, lakes, and oceans after precipitation.

Describe the role of the sun in the water cycle.

The sun provides the energy necessary for evaporation, driving the water cycle.