UWORLD CHEM 5/20/2020 Flashcards
Positron decay
Atomic number decreases
Isotopes
different numbers of neutrons
Chemical behavior
determined by the electron configuration
Physical and chemical properties of the isotope
They have a same chemical properties and different physical properties
Suppose that the (p-n) nuclear reaction described in the passage was attempted but resulted in the 18O nucleus absorbing a proton without ejecting a neutron. The resulting nucleus formed would be an isotope of
F is the isotope of O18
Radioactive decay
the time is required for the amount of isotope to become by half
Fraction remaining
1/2^n
Measured Activity
1/2^n *( Initial Activity)
molar mass
amount of mass compound in 1 mole of the compound
How products nad reactants are related to eachother
By the mole ratio
millimoles
Multiply by 4
Number of moles
Dividing the mass of sample by its molar mass
Electrostatic attraction
The van der Waals interaction between partially positive and negative molecules
Core Electrons
located between the valence electrons
Lewis Structure
Chemical compounds that repented by the dots and shows their valence electrons.
Octet Rule
S and P rech the full valence
Exceptions to octet rule
Small atoms such as H and He
Larger atoms in Period 3 have vacant d orbitals are utilized
SO3
is a bent.
Titrants
To find the mole of unknown
cv= mole
c= mole/v
Equivalent point
Moles of base= Moles of acid
Titrations
1. Strong/ Strong Strong acid & Strong base 2. Strong /Weak Strong acid/ weak base pH<7 Strong base/ weak acid pH>7
Polyprotic
A substance that can donate more than 2 protons
How many NaOH will take to kill H2A?
500 ml of 0.25 M of H2A
AND 0.25 OF NaOH
The first half point according to c1v1=c2v2 is 500.
The second equivalent point is 1000
Henderson Hasselback
pH= Pka+ log conjugate base/ acid
Buffers
Weak acid/ conjugate base
Weak base/ Conjugate acid