Chem Flashcards
what is an element?
a substance with only one type of atom
what is a compound?
a substance with two or more types of atoms that ARE chemically bonded
what is a mixture?
Substances that are made up out of two or more types of atoms but are NOT chemically bonded
what is an atom?
the smallest unit of matter that retains its properties
what is a molecule
a group of two or more atoms joined together
what is a ion
atom or molecule with a charge
describe the atoms in a liquid
they are still touching each other though they are in an irregular arrangement and are able to slide over each other
describe the atoms in a solid
they are all touching being closely packed together, and are in a regular arrangement. They cannot freely move but they vibrate, they also have the strongest intermolecular force.
describe the atoms in a gas
the particles are separated and move in fast speeds going in a straight line but randomly
what is the Solvent
is the liquid that the Solute dissolves in
what is the Solute
the solid that will be dissolved
what is the Solution
the mixture that is created when the Solvent dissolves in the Solute
how do you separate two miscible liquids on the basis of their boiling points?
fractional distillation
what is Filtration used for?
to separate a insoluble solid from the Solvent (liquid)
it traps the residue (insoluble) as it allows the solute (liquid) to pass through
what is the formula to calculate Rf value?
distance traveled by component/distance traveled by solvent
why do you draw the base line in pencil?
because pen would smudge and pencil won’t because it is insoluble
what are the characteristics of a physical change?
a usually reversible change in the physical properties of a substance, as size or shape
what are the characteristics of a chemical change?
A Chemical Reaction is a process that occurs when two or more molecules interact to form a new product(s).
what will you be left with in the process of evaporation
the solute
why does solubility increase with temperature?
because kinetic energy increases, which allows the solvent particles to break up the solute particles more easily
how does the atomic mass of an element affect its rate of diffusion
it diffuses faster
how do you calculate the solubility?
an ex is 20 g of a substance dissolves in 200cm3 of water. the equation would be
20-200 x= 20x100/200 = 10
x-200
what dose Evaporation and crystalisation do
it’s used to separate a soluble solid from a liquid. we use evaporation to turn the liquid into vapor leaving the solid behind.
what is Fractional distillation used for
it is every similar to simple distillation, though it is used to separate substances with similar boiling points.
what is simple distillation used for
its used to separate a liquid from a solid. its useful when we want to keep the liquid, separating substances with different boiling points
