Chapter 4 - Chapter 4 Types of Chemical Reactions And...

Info iconThis preview shows pages 1–6. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 4 Types of Chemical Reactions And Solution Stoichiometry Much of the chemistry that affects each of us and makes life possible occurs in aqueous (water) environment ( solution ). 4.1 Water the Common Solvent: Water has the ability to dissolve many different substances Water is a polar molecule δ + H O 2 δ - H δ + This polarity gives water its great ability to dissolve compounds Hydration of an ionic solid : 1. For cations : δ + H O 2 δ - M + H δ + 2. For anions : (a) δ + H O 2 δ - ( b ) δ + H O 2 δ - X - H δ + H δ + X -
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
The hydration of an ionic solid tends to cause a salt to fall apart or to dissolve in water H 2 O e.g: NaCl (s) Na + (aq) + Cl - (aq) H 2 O NH 4 NO 3 (s) NH 4 + (aq) + NO 3 - (aq) The solubility of ionic substances in water varies greatly depending on the relative attractions of the ions and water molecules. Water also dissolves many nonionic substances such as sugar and alcohols by hydrogen bonding H | e.g: C 2 H 5 -O-H …… O H 4.2 The Nature of Aqueous Solutions : Solution is a homogeneous mixture of solute dissolving in solvent (water). Substances ( solute ) can be classified into: 1. Nonelectrolytes : They dissolve in water and form no ions and therefore, their solutions have no electrical conductivity (e.g. sugar). 2
Background image of page 2
2. E lectrolytes : They dissolve in water and form ions. They can be: 1) Strong electrolytes : They are completely dissolved and their solutions have high electrical conductivity. e.g: strong acids and bases KOH (aq) K + (aq) + OH - (aq) 1 mol 1 mol 1 mol HCl (aq) H + (aq) + Cl - (aq) 1 mol 1 mol 1 mol H 2 SO 4 (aq) 2H + (aq) + SO 4 -2 (aq) 1 mol 2 mol 1 mol 2) Weak electrolytes : They are partially dissolved and their solutions have low electrical conductivity. e.g: organic acids and weak bases CH 3 COOH(aq) CH 3 COO - (aq) + H + (aq) acetic acid NH 3 (aq) + H 2 O(l) NH 4 + (aq) + OH - (aq) ammonia 3
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4.3 The Composition of Solutions : Molar concentration ( Molarity ) M : It is defined as moles of solute per volume of solutio n in liters: M = n / V mol/L ( See Figure 4.10 ) Example 4.1 : Calculate the molarity of a solution prepared by dissolving 11.5 g of solid NaOH in enough water to make 1.50 L of solution. Answer : n = m / MM = (11.5 g)/(40.00 g mol -1 ) = 0.288 mol NaOH M = n / V = (0.288 mol NaOH)/(1.50 L solution) = 0.192 M NaOH solution Example 4.2 : Calculate the molarity of solution prepared by dissolving 1.56 g of gaseous HCl in enough water to make 26.8 ml of solution. Answer : n = m / MM = (1.56 g)/(36.46 g mol -1 ) = 4.28 x 10 -2 mol HCl M = n / V = (4.28 x 10 -2 HCl)/(26.8 x 10 -3 L) = 1.60 M HCl solution 4
Background image of page 4
Example 4.3 : Give concentrations of each type of ion in the solutions: a) Ca(NO 3 ) 2 (aq) Ca 2+ (aq) + 2NO 3 - (aq) 0.50 M 0.50 M 1.00 M b) Fe(ClO 4 ) 3 (aq) Fe 3+ (aq) + 3ClO 4 - (aq) 1 M 1 M 3 M Example 4.4 : Calculate the number of moles of Cl - ions in 1.75 L of
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 6
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/25/2010 for the course CHEMISTRY 2010 taught by Professor Thwapiah during the Fall '10 term at Hashemite University.

Page1 / 19

Chapter 4 - Chapter 4 Types of Chemical Reactions And...

This preview shows document pages 1 - 6. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online