Practice Problems

Question 1

How to determine electron group arrangement

Answer 1

Look at number of effective pairs around central atom, this number corresponds to a shape

Question 2

What are the five options for electron group arrangement

Answer 2

Linear (2)

Trigonal planar (3)

Tetrahedral (4)

Trigonal bipyramidal(5)

Octahedral (6)

Question 3

How does paramagnetic react in a magnetic field

And why

Answer 3

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

Question 4

Three uses of hydrogen

Answer 4

Haber process

Hydrogenation of vegetable oils

Alternative fuel

Question 5

What is the most abundant element in the universe

Answer 5

Hydrogen

Question 6

Why does it have unique chemical behaviour

Answer 6

Small size

Question 7

What are two methods for producing hydrogen industrially

Answer 7

Water- gas shift reaction

Steam-hydrocarbon reforming

Question 8

Hydrogen reacts with metal to form an ___ ____

Answer 8

Ionic hydride

Question 9

Are ionic hydrides good reducing agents and why

Answer 9

Yes, because of precedes of H-

Question 10

Hydrogen reacts with non metals to form ___ ____

Answer 10

Covalent compounds

Question 11

Hydrogen reacts with transition metals to form ___ or ___ ___

The H atoms occupy the ____ spaces of the crystal structure of the transition metals

Answer 11

Metallic

Intersitial hydrides

Question 12

What state is the product of hydrogen and transition metals in

Answer 12

Gas solids (so no formula)

Question 13

Why is diamagnetic repelled by a magnetic field

Answer 13

Electrons are paired so their is no atomic dipole moments

Thus the induced dipoles oppose the magnetic field

Question 14

Which elements have incomplete octets and how many ve do they have

(4 elements)

Answer 14

Hydrogen (2)

Be (4)

B (6)

Al (6)

Question 15

What happens to bond length and energy when BOND ORDER INCREASES

Answer 15

They both increase as well

Question 16

What is an Arrhenius’s acid and base

Answer 16

Acid: yield an H+ when dissociated

Base: yields an OH- when dissociated

Question 17

What is a BL acid and Base

Answer 17

Acid: proton donor

Base: proton acceptor

Question 18

What is a Lewis acid and base

Answer 18

Acid: electron pair acceptor
(positive ions)

Base: structure has a lone pair to donate (negative ions)

Question 19

Acidity increases with more _____ (element)

Answer 19

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

Question 20

The more electronegative means the ____ acidic

Answer 20

More

Question 21

How to compare covalent character

Answer 21

Small EN difference = more covalent character

Question 22

How to compare ionic character

Answer 22

Large EN difference = more in Nov character

Question 23

How to determine melting point trends

Answer 23

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

Question 24

OS of hydrogen bonded to a non metal

Answer 24

+1

Question 25

OS of hydrogen bonded to a metal

Answer 25

-1

Question 26

Compound with a group 1A

(For the metal atom)

Answer 26

+1

Question 27

Compound with a group 2A

(For metal atom)

Answer 27

+2

Question 28

Oxygen

Answer 28

-2 (unless compound has O2 in it)

Question 29

Compound with a group 7A

(For non metal)

Answer 29

-1