Unit 8: Chemical Reactivity

What is Chemical Reactivity?

Chemical Reactivity explores how and why substances undergo chemical reactions. This unit focuses on the factors that influence the rate and outcome of chemical reactions, including the nature of reactants, reaction conditions, and mechanisms. Students study various types of chemical reactions, including synthesis, decomposition, single-replacement, and double-replacement reactions, and learn how to predict and analyze these reactions.

Key Topics in Chemical Reactivity:

• Types of Reactions: Understanding different types of chemical reactions, including synthesis, decomposition, single-replacement, and double-replacement.
• Reaction Rates: Examining factors that affect the speed of chemical reactions, such as concentration, temperature, and catalysts.
• Reaction Mechanisms: Studying the step-by-step processes by which reactions occur and how intermediates and transition states influence reaction pathways.
• Equilibrium: Learning about dynamic equilibrium in reversible reactions and how to use the equilibrium constant to predict the extent of reactions.
• Thermodynamics of Reactions: Exploring the energy changes associated with chemical reactions, including enthalpy, entropy, and Gibbs free energy.

Benefits of Studying Chemical Reactivity:

• Predictive Skills: Enhances the ability to predict the outcomes of chemical reactions based on reactants and conditions.
• Practical Knowledge: Provides insights into real-world applications, such as industrial processes, environmental reactions, and biochemical pathways.
• Scientific Understanding: Builds a foundation for more advanced studies in chemistry, including reaction kinetics and chemical engineering.

This unit is vital for students to understand the principles governing chemical reactions, their rates, and their mechanisms. Mastery of chemical reactivity is essential for applying chemistry knowledge to practical problems and advanced scientific studies.

1. Metals can form ions carrying charges:

a. Uni-positive
b. Di-positive
c. Tri-positive
d. All of them

2. Which one of the following metal burns with a brick red flame?

a. Sodium
b. Magnesium
c. Iron
d. Calcium

3. Sodium is extremely reactive metal, but it does not react with:

a. Hydrogen
b. Nitrogen
c. Sulphur
d. Phosphorus

4. Which one of the following is the lightest metal?

a. Calcium
b. Magnesium
c. Lithium
d. Sodium

5. Pure alkali metals can be cut simply by knife but iron cannot because of
alkali metals have:

a. Strong metallic bonding
b. Weak metallic bonding
c. Non-metallic bonding
d. Moderate metallic bonding

6. Which of the following is less malleable?

a. Sodium
b. Iron
c. Gold
d. Silver

7. Metals lose their electrons easily because:

a. They are electronegative
b. They have electron affinity
c. They are electropositive
d. Good conductors of heat

8. Which one of the following is brittle?

a. Sodium
b. Aluminium
c. Selenium
d. Magnesium

9. Which one of the following non-metal is lustrous?

a. Sulphur
b. Phosphorus
c. Iodine
d. Carbon

10. Non-metals are generally soft, but which one of the following is
extremely hard?

a. Graphite
b. Phosphorus
c. Iodine
d. Diamond

11. Which one of the following will not react with dilute HCl?

a. Sodium
b. Potassium
c. Calcium
d. Carbon