chem test unit 4
What is the charge on the anion in the ionic compound sodium sulfide?
2-
Which of these is the correct Lewis structure for nitrogen tri-iodide, NI3
:::I - :I:: - N: - :I::
Which of these is the correct Lewis structure for carbon dioxide, CO2
:O: = :C: = :O:
Which of these is the correct Lewis structure for diatomic Oxygen molecule, O2
:O: = :O:
An electron transfers from a sodium atom to a chlorine atom. What forms as a result
A sodium cation and a chlorine anion
An electron transfers from a sodium atom to a chlorine atom. What forms as a result?
A sodium cation and a chlorine anion
Which name/formula pairs are correct?
Aluminum Bromide, AlBr3; Lithium Fluoride, LiF
Which molecule has a trigonal pyramidal shape?
Ammonia (NH3)
How do dispersion forces compare to dipole interactions?
Both involve an electrical attraction between molecules, but dispersion forces are much weaker and temporary.
Which of the following linear molecules is a nonpolar molecule containing polar bonds?
CO2
Based on data from the periodic table, a student concluded that calcium sulfide is an ionic compound. Which drawing should the student use to communicate this conclusion?
Ca 2+ ::S::2-
What is the formula for calcium fluoride?
CaF2
Which name/formula pairs are correct
Cesium Phosphide, Cs3P, Beryllium Telluride, BeTe
Which of the following sets of elements is arranged in order of decreasing electronegativity?
Cl, S, Se
Which molecule has a single covalent bond?
Cl2
The ions Fe3+ and SiO32- form a salt with the formula __________.
Fe2(SiO3)3
Which name/formula pairs are correct
Gallium Iodide, GaI3
Which of these is the correct Lewis structure for hydrogen cyanide, HCN
H - c =- n..
Which molecule would have the largest dipole?
H2O
How does hydrogen bonding help explain the unique role of water in chemical systems?
Hydrogen bonding increases the intermolecular attractions among water molecules, allowing water to be a liquid over a wide range of temperatures.
Which is the most significant reason why intermolecular attractions are stronger among molecules of water (H2O) than molecules of ammonia (NH3)?
Hydrogen bonding is stronger among water molecules.
A water molecule (H2O) has a bent shape. Which other molecule has a bent shape?
Hydrogen sulfide (H2S)
Which formula/name pairs are incorrect?
MgSiO3 is Magnesium sulfite; CsNO3 is Calcium nitrate
What is the formula for sodium sulfate?
Na2SO4
An ionic bond forms when which event occurs?
One atom transfers one or more electrons to another atom, changing both atoms into ions.
n which of the following bonds is the bond polarity correct?
P->S
In structural formulas, polar covalent bonds are identified with symbols showing slightly positive charge (S+) and slightly negative charge (S-) next to the appropriate atoms. How are these symbols placed in the structural formula for H2O?
S- next to O, S+ next to both H symbol
How do electronegativity values determine the charge distribution in a polar covalent bond?
The more electronegative atom gains a slight negative charge; the less electronegative atom gains a slight positive charge.
Predict the geometric shape of BF3 molecule.
Trigonal planar
Which metal is capable of forming more than one cation
V
Why do metals tend to be good conductors of electric current?
Valence electrons of metals are very mobile and can carry electric current through the metal.
Which of the following best describes all the intermolecular forces exhibited by a pure sample of CH4?
dispersion forces
Which of the following is the strongest attractive force between molecules? a. dipole interactions
hydrogen bond
anion
negative ion
cation
positive ion
Electronegativity is a concept that is useful along with other concepts in
predicting the polarity of a bond.This answer is correct.
The electron configuration of a fluoride ion, F1-, is _______.
the same as that of a neon atom
Which formula/name pairs are incorrect?
. Ba2SO4 is Barium sulfate ; Na3PO3 is Sodium phosphate
What type of bond forms when one or more electrons transfer from one atom to another atom, changing both atoms into ions?
. Ionic bond
How many electrons will a sulfur (S) atom gain or lose in forming an ion?
. It will gain 2 electrons.
How many valence electrons are transferred from the nitrogen atom to potassium in the formation of the compound potassium nitride?
0
Identify the charge of the ion formed when a potassium atom loses one electron.
1+
Use VSEPR theory to predict the bond angles in a molecule of ammonia (NH3), which is a covalently bonded molecule.
107°
Use VSEPR theory to predict the bond angles in a molecule of methane (CH4), which is a covalently bonded molecule.
109.5°
What is the correct electron configuration for Cadmium after losing the outer s orbital to form Cd2+?
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10
What is the electron configuration of the iodide ion
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6
What is the electron configuration of the sodium ion, one of the two principal ions found in body fluids?
1s22s22p6