quiz 2 Flashcards
mass
the amount of matter in an object, independent of gravity
measured using grams
weight
a measure of the pull of gravity on an object
measured in newtons or pounds
volume of a rectangle
lwh
usually in cm^3
density
mass (g)/volume (mL)
if an object is less dense than its surroundings, it floats
if an object is the same density, it is suspended
if an object is more dense, it sinks
how can you measure the volume of an oddly shaped object?
submerge it in water. the amount of water displaced = volume
an intensive property
property is independent of the amount of substance
density is intensive
extensive property
property is dependent on amount of substance
mass and volume are extensive
matter
anything that occupies space and has mass
heterogeneous
mixture is not uniform throughout
homogenous
mixture is uniform throughout
compound
comprised of two or more elements
smallest unit of a compound
molecule
atoms
make up molecules and are connected through bonds. if it is cut, the results is subatomic particles
3 states of matter
solid, liquid, gas
bonus: aqueous, but it requires water and thus the matter is no longer pure
physical property
property that matter displays without changing its composition (chemical formula)
it is reversible
ex: color, malleability, conducting electricity, physical properties due to evaporation/condensation or freezing
chemical property
a property that matter displays with a change in its composition usual markers: -color change -production of odor -change of temperature -evolution of gas -precipitation
principle of the conservation of mass
mass is neither created nor destroyed
energy
is the capacity to do work and is not a form of matter since it does not have mass
law of conservation of energy
energy can neither be created nor destroyed. instead, there are only transfers of energy and changes of forms
kinetic energy
energy of motion
potential energy
stored energy
exothermic reaction
a reaction in which:
- heat EXits the reaction (ie hot pack)
- energy/heat is a product in a chemical reaction
- the reactants themselves contain more energy than the products
endothermic
a reaction in which:
- heat ENters the reaction (ie cold pack)
- energy/heat is a reactant in a chemical reaction
- the products themselves contain more energy than the reactants
the amount of heat required to raise the temperature of a substance is given by
Q=MC∆T
where q= the amount of joules required, M= the mass of the substance IN GRAMS, C= heat capacity of the substance (j/gc), ∆T= desired change in temperature IN CELSIUS
the chemicals that you start with in a chemical reaction are the
reactants
the chemicals that you end up with in a chemical reaction are the
products
1 mL = this cubic length measurement
1 mL = cm^3
the density of water is unique in that
it goes down when the temperature decreases, as its volume (the denominator in d) increases
for most other substances, as temp decreases, density increases as their volume decreases