Unit 1 Atomic Structure & Properties
A mass spectrum of an element shows two peaks: one at 35 amu with a relative intensity of 75%, and another at 37 amu with a relative intensity of 25%. What element is this most likely?
Chlorine
Which elements form hydrogen bonds with Hydrogen?
Nitrogen, Oxygen, and Fluorine (N, O, F)
Rank NaF, HF, F₂ from lowest to highest boiling point
F₂ < HF < NaF
LDF < hydrogen bonding < ionic
What is the loss of electrons called?
Oxidation
What is a bond formed by the transfer of electrons?
Ionic Bond.
What is the ground-state electron configuration for Co 2+ ion.
[Ar] 3d7
What is the bond angle of a trigonal pyramidal molecule?
107o (or slightly less than 109.5o)
What is the hybridization of Carbon in CO2?
sp hybridization
What are the ions called that do not participate in a chemical reaction?
Spectator ions.
Copper and zinc atoms have about the same radius. An alloy containing only copper and zinc would be called an ____________ alloy
Substitutional Alloy
If an electron is farther away from the nucleus, it then has ____ Coulombic attraction to the nucleus and is therefore ____ to remove?
lower ; easier
What type of solid conducts electricity only when liquid?
Ionic Solid
Which has the higher boiling point, NH3 or PH3?
NH3 (due to Hydrogen Bonding)
What is the stoichiometric point in a titration also called?
Equivalence Point
What are the 5 main types of chemical reactions?
Synthesis, Decomposition, Combustion, Single Replacement, Double Replacement
This periodic trend explains why Chlorine has a smaller atomic radius than Sodium.
How many sigma and pi bonds are in ethyne?
1 sigma and 2 pi bonds
Real gases to deviate from ideal behavior at _______ pressure and _________ temperature?
high pressure and low temperture
Why is HF not a strong acid?
Which compound has a higher lattice energy, MgO or NaF?
MgO, because the +2/-2 onic charge differential.
When reading a PES graph, the peaks with higher energy are located _______________ to the nucleus
closer
The formal charge on the central nitrogen atom in the nitrate ion?
+1
On a Phase Change Diagram, why does temperature remain constant during phase changes?
The added heat energy is being used to break intermolecular forces, not increase the temperature.
Which of the following pairs of liquids are most soluble in each other? CCl4 and H2O or CH3CH2OH and H2O
CH3CH2OH and H2O
What law explains why every sample of H2O is always 11% Hydrogen and 89% Oxygen by mass?
The Law of Definite Proportions (or Constant Composition)