Friday, January 12, 2007
Friday, Day 2
Regents/Honors: the molecular model lab writeup will be posted this weekend and the lab is due later next week. That is the last lab that will be covered on our quarterly lab exam, which is the last grade for the second quarter.
Honors: we began the second half of the bonding unit in which we make the DISTINCTION between a true BOND and a mere intermolecular "attraction". There are three and ONLY three true types of BONDS: (1.) ionic (2.) covalent (3.) metallic .
A MUCH weaker form of attraction exists in certain cases: (1.) ion-dipole attractions (as in aqueous solutions of ions) (2.) dipole-dipole attractions among/between polar molecules; there is an extreme form of this attraction UNFORTUNATELY named "hydrogen bonding" attraction and (3.) induced dipole attractions among/between nonpolar molecules.
We explained the relatively high melting points of ionic compounds which are due to the relatively strong attractive forces among ionically bonded cations and anions. We then began to account for the LACK of electrical conductivity of salts in the solid phase but the good electrical conductivity of molten/liquid salts.
Bonding practice test worksheets will be posted this weekend. Start work on them for next Thursday's Bonding Unit multiple choice exam. There are 200 points left to be earned this quarter.
Regents: We will go over the Bonding test on Monday; whatever you got wrong, you will have to write corrections (make SURE that they are perfect or you will lose points from your test) for homework.
We began the second half of the bonding unit in which we make the DISTINCTION between a true BOND and a mere intermolecular "attraction". There are three and ONLY three true types of BONDS: (1.) ionic (2.) covalent (3.) metallic .
A MUCH weaker form of attraction exists in certain cases: (1.) ion-dipole attractions (as in aqueous solutions of ions) (2.) dipole-dipole attractions among/between polar molecules; there is an extreme form of this attraction UNFORTUNATELY named "hydrogen bonding" attraction and (3.) induced dipole attractions among/between nonpolar molecules.
AP: we discussed catalysts and how they increase the number of effective collisions per second (by lowering the activation energy for an effective collision via orienting the reactant particle(s) properly) which increases the rate of a reaction.
We then discussed and graphically illustrated average and instantaneous rates of reaction, the rate units ( M per second).
We also related the rate of disappearance of a reactant to the rate of appearance of a product and related BOTH of those to the measured rate of reaction. To do this, we use the coefficients from the balanced equation.
Kinetics HW is posted on the website.
Honors: we began the second half of the bonding unit in which we make the DISTINCTION between a true BOND and a mere intermolecular "attraction". There are three and ONLY three true types of BONDS: (1.) ionic (2.) covalent (3.) metallic .
A MUCH weaker form of attraction exists in certain cases: (1.) ion-dipole attractions (as in aqueous solutions of ions) (2.) dipole-dipole attractions among/between polar molecules; there is an extreme form of this attraction UNFORTUNATELY named "hydrogen bonding" attraction and (3.) induced dipole attractions among/between nonpolar molecules.
We explained the relatively high melting points of ionic compounds which are due to the relatively strong attractive forces among ionically bonded cations and anions. We then began to account for the LACK of electrical conductivity of salts in the solid phase but the good electrical conductivity of molten/liquid salts.
Bonding practice test worksheets will be posted this weekend. Start work on them for next Thursday's Bonding Unit multiple choice exam. There are 200 points left to be earned this quarter.
Regents: We will go over the Bonding test on Monday; whatever you got wrong, you will have to write corrections (make SURE that they are perfect or you will lose points from your test) for homework.
We began the second half of the bonding unit in which we make the DISTINCTION between a true BOND and a mere intermolecular "attraction". There are three and ONLY three true types of BONDS: (1.) ionic (2.) covalent (3.) metallic .
A MUCH weaker form of attraction exists in certain cases: (1.) ion-dipole attractions (as in aqueous solutions of ions) (2.) dipole-dipole attractions among/between polar molecules; there is an extreme form of this attraction UNFORTUNATELY named "hydrogen bonding" attraction and (3.) induced dipole attractions among/between nonpolar molecules.
AP: we discussed catalysts and how they increase the number of effective collisions per second (by lowering the activation energy for an effective collision via orienting the reactant particle(s) properly) which increases the rate of a reaction.
We then discussed and graphically illustrated average and instantaneous rates of reaction, the rate units ( M per second).
We also related the rate of disappearance of a reactant to the rate of appearance of a product and related BOTH of those to the measured rate of reaction. To do this, we use the coefficients from the balanced equation.
Kinetics HW is posted on the website.
# posted by C @ 11:38 AM 
