Practice Problems Flashcards
How to determine electron group arrangement
Look at number of effective pairs around central atom, this number corresponds to a shape
What are the five options for electron group arrangement
Linear (2)
Trigonal planar (3)
Tetrahedral (4)
Trigonal bipyramidal(5)
Octahedral (6)
How does paramagnetic react in a magnetic field
And why
Attracted to magnetic field
Because of their spin, unpaired electrons have a net dipole moment
Magnetic field causes the electrons spin to align parallel to the field, causing attraction
Three uses of hydrogen
Haber process
Hydrogenation of vegetable oils
Alternative fuel
What is the most abundant element in the universe
Hydrogen
Why does it have unique chemical behaviour
Small size
What are two methods for producing hydrogen industrially
Water- gas shift reaction
Steam-hydrocarbon reforming
Hydrogen reacts with metal to form an ___ ____
Ionic hydride
Are ionic hydrides good reducing agents and why
Yes, because of precedes of H-
Hydrogen reacts with non metals to form ___ ____
Covalent compounds
Hydrogen reacts with transition metals to form ___ or ___ ___
The H atoms occupy the ____ spaces of the crystal structure of the transition metals
Metallic
Intersitial hydrides
What state is the product of hydrogen and transition metals in
Gas solids (so no formula)
Why is diamagnetic repelled by a magnetic field
Electrons are paired so their is no atomic dipole moments
Thus the induced dipoles oppose the magnetic field
Which elements have incomplete octets and how many ve do they have
(4 elements)
Hydrogen (2)
Be (4)
B (6)
Al (6)
What happens to bond length and energy when BOND ORDER INCREASES
They both increase as well
What is an Arrhenius’s acid and base
Acid: yield an H+ when dissociated
Base: yields an OH- when dissociated
What is a BL acid and Base
Acid: proton donor
Base: proton acceptor
What is a Lewis acid and base
Acid: electron pair acceptor
(positive ions)
Base: structure has a lone pair to donate (negative ions)
Acidity increases with more _____ (element)
Oxygen
Oxygen is very EN so more electron density is pulled away from the acidic proton, therefore increase the polarity of the O—-H bond
The more electronegative means the ____ acidic
More
How to compare covalent character
Small EN difference = more covalent character
How to compare ionic character
Large EN difference = more in Nov character
How to determine melting point trends
1) look at charges
-elements in compounds with GREATER numerical charge have HIGHER melting point
2)if two compounds have elements of the same charge: look at atomic mass of elements in each compound
-greater atomic mass=larger distance between nucli= smaller LE=lower melting point
OS of hydrogen bonded to a non metal
+1
OS of hydrogen bonded to a metal
-1
Compound with a group 1A
(For the metal atom)
+1
Compound with a group 2A
(For metal atom)
+2
Oxygen
-2 (unless compound has O2 in it)
Compound with a group 7A
(For non metal)
-1
