Chemistry Flashcards
Carbon 12 atomic weight
1.99 x 10^–26 kg
1 amu
1/12 carbon-12 mass
____ de un atomo es aproximadamente igual al numero deprotones y neutrones en el nucleo
Atomic weight
____ de un atomo es igual al numero de protones en el nucleo
Atomic number Z
Substance that cannot be decompesed into simpler substances during ordinary chemical reactions
Element
Atomos de un elemento que pueden tener diferentes atomic weight
Isotopes
difieren solo en el numero de neutrones
A combination of elements
Compound
The smallest subdivision of an element of an element or compound that can exist in natural state
Molecule
The smallest subdivision of an element that can take part in a chemical reaction
Atom
Halogens and Noble gas are
Nonmetals
The ___ have poor electrical conductors and have little or no metallic luster.
Nonmetals
Alkali Metals, Alkaline Earth Metals, Transition Metals, Lanthanides, Actinides are
Metals
____ have low electron affinities, are reducing agents, form positive ions, and have positive oxidation numbers, high electrical conductivity, luster, ductility and maleability.
Metals
Negative charged ions are known as
Anions
Positively charged ions are known as
cations
Anios lose electrons at the anode during elctrochemical reactions. Anions must lose electros to become neutral. Meanwhile, Cations gain electrons at the cathode in electrochemical reactions. Cations hani electrons to become neutral (T o F)
True
Al que le quitan el electron que termina siendo + es el cation
Al que le dan el electron que termina siendo - es el anion. Pq al inicio ambos son neutrales.
The charge on an anion is equal to the numer of electros taken from a neighboring atom. This charge is known as
Valence = numero de electrones que debe ser ganado for charge neutrality.
Type of bonding, in which electrostatic attraction is predominant is known as_____. One or more electrons are transferred from the valence shell of one atom to the valence shell of another.
Ionic Bonding
Diatomic - Common gases
H2, O2, N2, Cl2
Type of bonding in which sharing of electrons is the predominant characteristic, is known _____. Are typically formed in organic compounds.
Covalent Bonding
Both atoms forming a covalent bond of the same element share equally the electrons
Nonpolar covalent bond
Atoms that are not both the same element do not share the electrons equally
Polar covalent bond
For atoms in an elementary free state, the oxidation number is
zero
For monoatomic ions, the oxidation number is
the charge
The oxidation number of an atom that forms a covalent bond is equal to
the number of shared electron pairs
Always composed of the same elements combined in a definite proportion by mass
Pure Compound
Avogadro #
1 mol = 6.02 x 10^23
1 mol = 1 gram-mole
The ___ of a molecule (compound) is the sume of the atomic weights of all elements in the formula
Formula Weight
The ____ is the sum of the atomic weights of all atoms in the molecule.
Molecular Weight
The ___ is the amount of substance (in g) that supplies one gram-mole of reacting units. MW/delta oxidation number
Equivalent Weight
Equal volumes of all gases at the same temprature and pressure (specifically STP) contain equal numbers of gas molecules
Avogadro Hypothesis
Los coeficientes enfrente de un elemento en una reaccion quimica son moleculas o moles. Pero en los gases, los coeficientes tambn representan el numero de volumen. (T o F)
Cierto
In the ____, the substance loses electrons, and the substance become less negative. This occurs in the anode.
Oxidation
Inthe ____, the substance gains electrons, and the substance becomes more negative. This occurs at th cathode.
Balance Redox Eqtn
- Separar las ecuaciones en la de ox y la de red
- Balancear los elementos fuera de los ox y los hydrogen
- Luego balancear los ox con H2O
- Luego balancear los h con h+
- Luego balancear los electrones
- Las dos ecuacioenes redox y ox deben tener las mismas cantidades de electrones so mult por factor si es necesario
- Unir las ecuaciones y cancelar los electrones
Rate Reaction se puede afectar por los siguientes factores
Tipos de sustancias en la reaccion
Exposed surface area
Concentrations
Temperatire
Catalysts
Molaridad
M = n/V
n = moles del soluto
V = volumen de la solucion
Any compound that dissociates in water into H+ ions.
Acid
Any compound that dissociates water into OH- ions
Base
Acid properties are
- Conducts electicity in aqueous solutions
- Sour Taste
- Turn blue litmus paper red
- have a pH between 0-7
- Neutralize bases
- Reacts with active metals to form Hydrogen
- Reacts with oxides and hydroxides of metals to form salts and water
- Reacts with salts to form new salt and new acid
Base properties are
- Conduct electricity in aqueous solutions
- Have bitter taste
- Turn red litmus paper blue
- Have a pH between 7-14
- Neutralize acids, forming salts and water
Acids and Bases formulas
pH = log10 (1/[H+])
pOH= - log10 [oH-} = log10 (1/[oH-])
[] - ionic concentrations in moles of ions per liter
Molality
molality = mol solute / kg solvent
molar fraction
x = mol A / total mol
Faraday’s Laws of electrolysis
- The mass of a substance generated by electrolysis is proportional to the amount of electricity used.
- For any constant amount of electricity, the mass of substance generated is proportional to its equivalent weiht
- One faraday of electricity will produce one gram equivalent weight.
Oxidarion Numbers of Atoms (Table)
Ejercicios: Para encontrar la masa de un atomo de un elemento
Molar Weight / Avogadros #
Ley que establece que a P = constante el volumen de un gas varia directamente con la temperatura absoluta
Charles Law
Ley que establece que a T=constante el volumen de un gas varia inversamente proporcional con la presion absoluta
Boyle Law
Ley que establece que la presion total de un gas es igual a la suma de las presiones ejecidad por los componentes individuales del gas (presiones parciales)
Dalton Law
Ley que establece que en una room temperature, la suma de los heat capacities de elementos individuales de u solido son aproximadamente igual al total heat capacity del solido
Kopp Law
Un gas se considera ideal cuando su presion es bien bajita y su tempratura bien alta. Bajo estas condiciones la distancia de las moleculas es grande y la interaccion es minima (T o F)
True
Atomic radii in the periodic table
Decrease to the right
Increase to the bottom
Electronegative in the periodic table
Increase to the right
Increase to the toop
