chemistry part-2 Flashcards
what drives chemistry?
- kind of bonds between atoms in compounds.
- movement of electrons (valence electron at the most outer shell moves around)
- molecule size and shape
- temperature
Type of bonds
- Ionic
- covalent
how to determined type of bond
by the power of an atom to attract electrons to itself.
Covalent bonds
- formed between atoms with similar electronegative.
- share electrons from outer molecular orbit.
- these bonds are formed between non-metal atoms.
- definite shape
- low melting point
- low boiling point
ex: methane(CH4), hydrochloric acid (HCI)
Ionic bond
- formed between atoms with different electronegative.
- one of the atoms will lose the electron to the other atom (in covalent they share)
- transfer of electrons between atoms.
- this results In cation and anion.
- formed between metal and non-metal atoms
- no defined shape.
- high melting point and boiling point
ex: sodium chloride (NaCl)
Cation
positively charged ion (+1)
when they lose electrons.
Anion
Negatively charged ion (-1)
when they gain electrons.
Electrolytes in body fluid
sodium Na+ Chloride Cl- Magnesium Mg2+ Calcium Ca2+ Potassium K+
What have full valence electron configuration?
Noble gases means full outer energy level
- last row of periodic table is know as noble gases because it has a full valency election, the outer shell has full electrons.
Why electron moves
to becomes as astable as group 18 noble gases
Types of molecules
polar and non-polar
is single oxygen, O, molecule?
no
Types of molecules
polar and non-polar
Types of covalent bond
polar and non-polar
Polar molecules
- electrons are not equally shared
- one part of molecule is more negative that the other
- so, molecule has negative and positive poles
- hydrophilic (‘water loving’)
Non-polar molecules
- electron are equally shared
- there is no poles.
- hydrophobic (water fearing)
polar covalent
- atoms with different electronegativities bound together.
- occur between different atom types
- bonding electrons found closer to one atom
non-polar covalent
- atoms with similar electronegativities bound together.
- occur between identical atom types
- bonding electrons found halfway.
what kind of molecules can be mixed in another
molecules of similar polarity
example of polar substances
water, salt, sugar, blood, ammonia, ethanol
example of non-polar substances
fat, oil, wax, petrol, butter, soap, bubblegum
does oil mix with blood?
no
what if you give injection of oil to your patient?
it would form a blood clot because blood is polar as it contains water and oil is non polar.
- only molecule with similar polarities can be mixed.
what can trigger different smells in the nose
shape of molecules
how does temperature affect chemical
high temperature can change the chemical
what is protein denaturation? is it bad?
yes it is
lose of shape =
lose of function
hydrogen bond
- bond between hydrogen atom and another atom. ex: H2O water
- partially electrostatic force of attraction- weaker than covalent or ionic bonds
- hydrogen act as a proton donor (positive)
- It bonds with another atom with a lone electron pair (negative)
- This type of bond can occur in inorganic molecules (water) and in organic molecules e.g. DNA and proteins.
is hydrogen bond weaker than covalent or iconic bond
yes
element that act as a proton donor
hydrogen
what is molecular mass (weight) of compound?
Sum of (relative) atomic masses of the elements in a compound
ex: carbon dioxide (compound)
carbon (element) - atomic mass 12.1 (x 1- no of atoms) 12
oxygen - atomic mass 16 (x 2) 32
Molecular mass = 12.1 + 32 = 44.01
mole
chemical name for specific number of particles in substance.
- this could be atoms/ions/molecules
- known as Avogadro’s number
- a really large number
- Used as an expression of concentration
what is known as Avogadro’s number?
mole
normal NZ blood glucose?
4-8 millimoles/litre = mol/litre
mole equation
n = m/M m = mass of material weighted from analytical balance (grams, g) M = molecular mass of material calculated using periodic table. (grams per mol, / g/mol) n= number of moles (unit can be atoms, ions, molecules)
how many moles are there in 213g of lithium perchlorate (LiClO4)?
M = 7 (Li)+
35.5 (Cl)+
64 (16x4) (Oxygen)
= 106.5g Total
n = 213 g /106.5 g/mol (n=m/M)
n= 2 molNZ recommendation: Limit Salt intake per day?
2300 mg per day
Excess sodium in blood called?
Hypernatremia
What is Normal sodium level?
135–145 mmol/L
Symptoms of Hypernatremia
- Thirsty az
- vomiting
- diarrhoea
- fever
Concentration definition
amount of stuff(solute) in a bigger amount of stuff (solvent)
solute/solvent
Volume percentage equation
𝑉𝑜𝑙𝑢𝑚𝑒 𝑝𝑒𝑟𝑐𝑒𝑛𝑡=(𝑚𝑎𝑠𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒)/(𝑣𝑜𝑙𝑢𝑚𝑒 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛)×100%
Mass percentage equation
mass percentage = mass of solute/ mass of solution x100
mass of solute = gram of solute
mass of solution = grams of solute + grams of solvent
Dose calculation equation
amount to administer = weight x dosage / drug strength
therapeutic effect depends on…
concentration and there are many units of concentration.
Why do atoms form ions?
Atoms form ions to gain a full valence shell of electrons
when atom loose or gain electrons they form ion.
what is electron configuration for a beryllium atom?
2,2
Predict the ion formed by beryllium and its electron configuration.
The ion will form when Be loses 2 electrons to become Be2+
with an electron configuration of 2
By transfer of electrons from one atom to another. this is known as________ bonding.
ionic bonding
By the share of electrons from one atom to another. this is known as________ bonding.
covalent
which statement about non-polar covalent bond is correct?
- gain electrons
- equally share electrons
- lose electrons
- unequally share electrons
equally share electrons.
Molecules
are atoms that are chemically bonded together and are an electronically neutral group
elements react in order to achieve the ________. by doing this they achieve the_______.
full outer energy level.
electronic structure of the noble gases (full outer energy level).
When metal reacts with non-metal this is a ____ bonding
ionic
