Chapter 5 Reactivity PDF

# Chapter 5: Reactivity ## 1. Reactivity of Metals - **Definition:** Reactivity is the tendency of a substance to undergo chemical reactions. - **Key Concept:** Metals react with other substances based on their position in the reactivity series. - **Reactivity Series:** * **Highly reactive met...

# Chapter 5: Reactivity ## 1. Reactivity of Metals - **Definition:** Reactivity is the tendency of a substance to undergo chemical reactions. - **Key Concept:** Metals react with other substances based on their position in the reactivity series. - **Reactivity Series:** * **Highly reactive metals:** Potassium (K), Sodium (Na), Calcium (Ca) * **Moderately reactive metals:** Magnesium (Mg), Aluminum (Al), Zinc (Zn) * **Less reactive metals:** Iron (Fe), Lead (Pb), Copper (Cu) * **Unreactive metals:** Silver (Ag), Gold (Au) ## 2. Reactions with Oxygen - **Highly reactive metals** form oxides quickly when exposed to air. **Example:** Magnesium + Oxygen → Magnesium Oxide (2Mg + O2 → 2MgO) - **Less reactive metals** form oxides slowly or require heating. ## 3. Reactions with Water - **Highly reactive metals** (e.g., Potassium, Sodium) react violently with water: Metal + Water → Metal Hydroxide + Hydrogen Gas (e.g., 2Na + 2H2O → 2NaOH + H₂) - **Less reactive metals** (e.g., Magnesium) react with steam, not cold water. ## 4. Reactions with Acids - **General Reaction:** Metal + Acid → Salt + Hydrogen Gas - **Example:** Zn + HCl → ZnCl2 + H2 - **Observation:** Effervescence indicates hydrogen gas production. ## 5. Displacement Reactions - **Definition:** A more reactive metal displaces a less reactive metal from its compound. - **Example:** Zinc displaces Copper from Copper Sulfate: Zn + CuSO4 → ZnSO4 + Cu. - **Practical Use:** Extracting metals from ores. ## Formation of Salts ### 1. What Are Salts? - **Definition:** Salts are ionic compounds formed when the hydrogen ion (H+) in an acid is replaced by a metal ion or an ammonium ion (NH4+). | Name of acid | Formula | Salts formed from the acid | Example of Salt | Formula of Salt | |---|---|---|---|---| | hydrochloric acid | HCI | Chlorides | Sodium Chloride | NaCl | | sulfuric acid | H2SO4 | Sulfates | Copper sulfate | CuSO4 | | nitric acid | HNO3 | Nitrates | Potassium nitrate | KNO3 | ### 2. Methods of Salt Formation #### a. Metal + Acid - **Reaction:** Metal + Acid → Salt + Hydrogen Gas. - **Example:** Zinc + Sulfuric Acid → Zinc Sulfate + Hydrogen Gas.<br> Zn + H2SO4 → ZnSO4 + H2. #### b. Metal Oxide + Acid - **Reaction:** Metal Oxide + Acid → Salt + Water. - **Example:**<br> Copper(II) Oxide + Hydrochloric Acid → Copper(II) Chloride + Water. <br> CuO + 2HCl → CuCl2 + H2O. #### c. Metal Carbonate + Acid - **Reaction:** Metal Carbonate + Acid → Salt + Water + Carbon Dioxide. - **Example:**<br> Calcium Carbonate + Nitric Acid → Calcium Nitrate + Water + Carbon Dioxide. <br> CaCO3 + 2HNO3 → Ca(NO3)2 + H2O + CO2. #### d. Alkali + Acid (Neutralization Reaction) - **Reaction:** Metal Hydroxide + Acid → Salt + Water. - **Example:** Sodium Hydroxide + Hydrochloric Acid → Sodium Chloride + Water.<br> NaOH + HCl → NaCl + H2O. #### 4. Metal Carbonate + Acid → Salt + Water + Carbon Dioxide ##### a. Simple Equations 1. Write the word equation for the reaction between calcium carbonate and hydrochloric acid 2. What gas is released during the reaction of sodium carbonate with sulfuric acid, and how can it be identified? ### 3. Alkali and Bases - Metal oxides are bases - If these bases are soluble in water they form alkalis. ## Practice Questions on Formation of Salts ### 1. Metal + Acid → Salt + Hydrogen #### a. Simple Equations 1. Write the word equation for the reaction between magnesium and sulfuric acid. 2. Predict the products of the reaction between zinc and hydrochloric acid. ### 2. Metal Oxide + Acid → Salt + Water #### a. Simple Equations 1. Write the word equation for the reaction between copper(II) oxide and nitric acid. 2. What are the products when aluminum oxide reacts with hydrochloric acid? ### 3. Metal Hydroxide + Acid → Salt + Water #### a. Simple Equations 1. Write the word equation for the neutralization reaction between potassium hydroxide and sulfuric acid. 2. Predict the products of sodium hydroxide reacting with nitric acid. ## Part B Rearranging Atoms ### 1. What is Rearranging Atoms? - During a chemical reaction, atoms in the reactants rearrange to form new products. - **Key Concept:** No atoms are created or destroyed (Law of Conservation of Mass). ## 3. Representing Chemical Reactions ### Balancing Chemical Equations - To obey the Law of Conservation of Mass, the number of atoms for each element must be equal on both sides of the equation. - When a reaction is taking place: - **1) Colour change is observed** - **2) Bubbles are seen** - **3) Test tube feels warm** Please note: This is a markdown version of the document, and does not include the image or links to an image.