userdata-paziras-Chem101-Chap_12A

Of ions returning nrofnrof ionsions disso lving

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: salt water 40 g undisso lved NaCl Na+ and Cl- io ns: ­ leave the crystal ­ disso lve in water 24 g undisso lved NaCl Nr. of ions disso lving 12 g undissoved NaCl Nr. of ions returning Nr. of Nr. of ions ions disso lving returning 4 g undissoved NaCl Nr. of Nr. of ions = ions dissolving returning Dynamic equilibrium has been established NaCl(s) 3 NaCl(aq) Chemistry 101 Chapter 12 AT EQUILIBRIUM Rate at which ions leave the crystal Rate at which ions return to the crystal Rate of disso lving Rate of crystallization NaCl(s) NaCl(aq) · The composit ion o f the solut ion no longer changes · A saturated solut ion has been obtained CONCLUSIONS: o · At 20 C no more than 36 g of NaCl can disso lve in 100 g of water. Solubilit y of a substance: Ø is the amount of substance that can be disso lved in 100 g of so lvent at a given temperature. o Ex: The solubilit y of NaCl at 20 C is 36 g NaCl/100 g water Saturated Solut ion: Ø A so lut ion containing the maximum amount of solute that can be disso lved in a given amount of solvent at a given temperature o Ex: At 20 C, a solution containing 36 g of NaCl disso lved in 100 g of water Unsaturated Solut ion: Ø A so lut ion containing less than the maximum amo unt of so lute that can be disso lved in a given amount of so lute at a given temperature o Ex: At 20 C, a solution containing 28 g of NaCl disso lved in 100 g of water (8 g more of NaCl can be disso lved) Supersaturated Solut ion: Ø A so lut ion containing more disso lved so lute that a saturated solut ion 4 Chemistry 101 Chapter 12 FACTORS AFFECTING SOLUBILITY · Why do some substances mix and others do not ? · There are 2 main factors that determine the so lubilit y o f a substance in a given so lvent. I. TENDENCY TOWARD DISORDER (Tendency toward a state of lower energy) Substances have a natural tendency to mix. Ex: all gases are miscible in each other This factor favors the disso lving process NOTE: If this were the only factor, all substances would have unlimited so lubilit y in each other. II. RELATIVE FORCES OF ATTRACTION BETWEEN SOLUTE AND SOLVENT SPECIES There are 3 types of forces of attraction: 1. Between solute ® ¬ solvent Favor the disso lving process particles 2. Between solute ® ¬ solute Works against the disso lving process particles 3. Between solvent ® ¬ solvent Works against the disso lving process particles CASE 1: The forces of attraction between solute and solvent particles The forces of attraction between This happens...
View Full Document

This document was uploaded on 03/18/2014 for the course CHEM 101 at Los Angeles Mission College.

Ask a homework question - tutors are online