# Gannon University Magnesium Phosphorus and Oxygen Exam Questions

• 1. A compound that is composed of Phosphorus and Oxygen only which contains 43.66% P by mass and (unknown %) of Oxygen. What is the empirical formula of the compoud
• 2. Magnesium and nitrogen react in a combination reaction to produce magnesium nitride Mg3N2: In a particular experiment, a 9.27-g sample of reacts completely to yield 15.3g of Magnesium nitride. Calculate the percentage yield of Mg3N2
• 1-The combustion 28.8 g of ammonia in the presence of excess oxygen yields and
• How many grams of NO2 produce?

• 3-Given the following reaction: Na2S2O3 + AgBr → NaBr + Na3[Ag(S2O3)2] How many moles of Na2S2O3 are needed to react completely with 42.7 g of AgBr?
• 4. What mass in grams of hydrogen is produced by the reaction of 4.73 g of magnesium with 1.83 g of water? Mg (s) + 2H2O(l) → Mg(OH)2 (s) + H2 (g)

Quantum Mechanics
Erwin Schrödinger
developed a
mathematical treatment
into which both the
wave and particle
nature of matter could
be incorporated.
It is known as quantum
mechanics.
Quantum Mechanics
The wave equation is
designated with a lower
case Greek psi (ψ).
The square of the wave
equation, ψ2, gives a
probability density map of
where an electron has a
certain statistical likelihood
of being at any given instant
in time.
Quantum Numbers
Solving the wave equation gives a set
of wave functions, or orbitals, and their
corresponding energies.
Each orbital describes a spatial
distribution of electron density.
An orbital is described by a set of three
quantum numbers.
Principal Quantum Number (n)
The principal quantum number, n,
describes the energy level (shell) on
which the orbital resides.
The values of n are integers ≥ 1.
The number of electrons in the shell
estimated by = 2n2
Excirse
How many orbitals are in n=4 ?
How many electrons are in n=3?
Angular Momentum Quantum
Number (l)
This quantum number defines the
shape of the orbital.
Allowed values of l are integers ranging
from 0 to n − 1.
We use letter designations to
communicate the different values of l
and, therefore, the shapes and types of
orbitals.
Exrscise
How many orbitals if n=3 l=2 ?
How many electrons if n=3 , l=1 ?
Angular Momentum Quantum
Number (l)
Value of l 0
Type of orbital
s
1
2
3
p
d
f
Magnetic Quantum Number (ml)
The magnetic quantum number
describes the three-dimensional
orientation of the orbital.
Allowed values of ml are integers
ranging from -l to l:
−l ≤ ml ≤ l.
Therefore, on any given energy level,
there can be up to 1 s orbital, 3 p
orbitals, 5 d orbitals, 7 f orbitals, etc.
Magnetic Quantum Number (ml)
Orbitals with the same value of n form a shell.
Different orbital types within a shell are
subshells.
s Orbitals
The value of l for s
orbitals is 0.
They are spherical in
shape.
sphere increases with
the value of n.
s Orbitals
Observing a graph
of probabilities of
finding an electron
versus distance from
the nucleus, we see
that s orbitals possess
n−1 nodes, or regions
where there is 0
probability of finding an
electron.
Exercise
How many nodes in 3S?
p Orbitals
The value of l for p orbitals is 1.
They have two lobes with a node between
them.
d Orbitals
The value of l for a
d orbital is 2.
Four of the five d
orbitals have 4
lobes; the other
resembles a p
orbital with a
doughnut around
the center.
Energies of Orbitals
For a one-electron
hydrogen atom,
orbitals on the same
energy level have
the same energy.
That is, they are
degenerate.
Energies of Orbitals
As the number of
electrons increases,
though, so does the
repulsion between
them.
Therefore, in manyelectron atoms,
orbitals on the same
energy level are no
longer degenerate.
Spin Quantum Number, ms
In the 1920s, it was
discovered that two
electrons in the same
orbital do not have
exactly the same energy.
The “spin” of an electron
describes its magnetic
field, which affects its
energy.
Spin Quantum Number, ms
This led to a fourth
quantum number, the
spin quantum number,
ms.
The spin quantum
number has only 2
allowed values: +1/2
and −1/2.
Pauli Exclusion Principle
No two electrons in the
same atom can have
exactly the same energy.
Therefore, no two
electrons in the same
atom can have identical
sets of quantum
numbers.
Exercise
How many electron if n=3 l=2 ml=-2
ms= -1/2 ?
Electron Configurations
This shows the
distribution of all
electrons in an atom.
Each component
consists of
A number denoting the
energy level,
Electron Configurations
This shows the
distribution of all
electrons in an atom
Each component
consists of
A number denoting the
energy level,
A letter denoting the type
of orbital,
Electron Configurations
This shows the
distribution of all
electrons in an atom.
Each component
consists of
A number denoting the
energy level,
A letter denoting the type
of orbital,
A superscript denoting
the number of electrons
in those orbitals.
Exercise
Write electron configuration of Cr.
……………………………………….
Write electron configuration of Cl by
using noble gases .
……………………………………….
Orbital Diagrams
Each box in the
diagram represents
one orbital.
Half-arrows represent
the electrons.
The direction of the
arrow represents the
relative spin of the
electron.
Hund’s Rule
“For degenerate
orbitals, the lowest
energy is attained
when the number of
electrons with the
same spin is
maximized.”
Periodic Table
We fill orbitals in
increasing order of
energy.
Different blocks on the
in different colors in
this chart) correspond
to different types of
orbitals.
Some Anomalies
Some
irregularities
occur when there
are enough
electrons to halffill s and d
orbitals on a
given row.
Some Anomalies
For instance,
the electron
configuration for
copper is
[Ar] 4s1 3d10
rather than the
expected
[Ar] 4s2 3d9.
Some Anomalies
This occurs
because the 4s
and 3d orbitals
are very close in
energy.
These anomalies
occur in f-block
atoms, as well.
The Periodic Table
Dmitri Mendeleev
and Lothar Meyer
independently came
to the same
how elements
should be grouped.
Atomic Symbols
Short hand way of representing the element Each element is
assigned by a unique symbol which is 1-2 letters and the first
is capitalized.
Symbol may not match the name –often had a different name
Examples:
Elements Symbols
Element
Symbols
Hydrogen H
mercury
Hg
gold Au
helium
He
arsenicAs
potassium K
barium Ba
nickel
Ni
carbon C
nitrogen
N
chlorine
Cl
oxygen O
uranium
U
Modern Long Form of Periodic Table
Table of elements has been constructed on the basis of
electronic structures of elements.
a)
b)
The elements are arranged in order of their atomic numbers.
An element is placed in that group of periodic whose group
number is equal to the number of valence electrons.
c) Table contains eight groups (vertical column of the periodic
table) – group I, II, III, IV, V, VI,VII and VIII .
These groups are: IA, IB, IIA, IIB,………..,
VIIIA or group 0 and group VIIIB
d) Each group from group I to group VIII is sub-divided into
two groups such as A & B.
e) There are seven horizontal rows or periods.
Modern Long Form of Periodic Table
Elements are classified into:
1- Representative elements
The groups labeled with the
letters A
(Groups IA,…….,VIIIA or
group 0 ) are referred to
collectively as representative
element.
2- Transitional (middle)
elements
Groups IB —-VIIIB.
3- Inner transitional
elements
Two long rows of elements
placed just below the main
part of the table
Development of Periodic Table
Dmitri
Mendeleev and
Lothar Meyer
independently
came to the
same
conclusion
elements should
be grouped
Development of Periodic Table
Elements in the same
group generally have
similar chemical properties.
Physical properties are not
necessarily similar.
1- A compound that is composed of Phosphorus and Oxygen only which contains 43.66% P
by mass and (unknown %) of Oxygen. What is the empirical formula of the compound?
2- Magnesium and nitrogen react in a combination reaction to produce magnesium nitride
Mg3N2:
3 Mg + N2 → Mg3 N2
In a particular experiment, a 9.27-g sample of N 2 reacts completely to yield 15.3g of Magnesium
nitride. Calculate the percentage yield of Mg3N2
Page 1 of 2
3- The combustion 28.8 g of ammonia in the presence of excess oxygen yields NO 2 and H 2 O
4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)
How many grams of NO2 produce?
4-
Given the following reaction: Na2S2O3 + AgBr → NaBr + Na3[Ag(S2O3)2]
How many moles of Na2S2O3 are needed to react completely with 42.7 g of AgBr?
5- What mass in grams of hydrogen is produced by the reaction of 4.73 g of
magnesium with 1.83 g of water? Mg (s) + 2H2O(l) → Mg(OH)2 (s) + H2 (g)
Page 2 of 2

Don't use plagiarized sources. Get Your Custom Essay on
Gannon University Magnesium Phosphorus and Oxygen Exam Questions
Just from \$13/Page
Pages (550 words)
Approximate price: -

Why Work with Us

Top Quality and Well-Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Free Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.

Prompt Delivery and 100% Money-Back-Guarantee

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

## Calculate the price of your order

Total price:
\$0.00

How it works?

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.

## Essay Writing Service

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.