Lab practical!! Flashcards
density of displacement=
mass of object / volume of displacement
percent yield=
actual / theoretical times 100
what happens to the validity of a calorimetry experiment that is open (not closed)
-The temp change in water will not be as high as it should be
-heat gained by water will not be fully accurate making the set up less efficient
Pressure (P) of total =
pressure atm (atmosphere)
P tot=
P of carbon dioxide gas + P water vapor + Δh/13.6
P atm=
P carbon dioxide gas + P water vapor + Δh/13.6
P carbon dioxide gas=
P atm - P water vapor - Δh/13.6
E=
hc/ lamda (wavelength)
when reading a graduated cylinder
read from the bottom of the meniscus
it has 3 sig figs so ONE decimal place
filtration (from book)
one component dissolves in water
mixture is separated by filter funnel and filter paper
solid is collected on paper
liquid flows through paper is the filtrate
dislillation
process of separating components from liquid mixtures through vaporization condensation based on their different boiling points
difference between gravity filtration and vacuum filtration
vacuum uses the nose on the side of the beaker with rubber tube
gravity is just the filter paper and waiting for the filtrate to come down
cathode (from google)
species gains electrons
Cu2(+) (aq) + 2e- = Cu(s)
anode (from google)
oxidation reaction that releases reactions or loses electrons
Zn(s) = Zn2+ (aq) + (2e-)
what are the steps in the copper cycle
(1) dissolving copper in nitric acid to form copper(II) nitrate, (2) precipitating copper(II) hydroxide by adding sodium hydroxide, (3) heating the copper hydroxide to form copper(II) oxide, (4) dissolving the copper oxide in sulfuric acid to form copper(II) sulfate, and (5) using zinc metal to displace and recover the copper metal from the solution
the first step in the copper cycle is a
redox reaction
when measuring the density of a rod
-weigh the rod
-use displacement (final-initial change in vol)
-do grams change to get grams over ml
-so mass/vol
sig figs in graduated cylinder
just to the tenths place
sig figs on a ruler
just to the tenths place
sig figs in a buret
to the hundredths place (2 decimal places)
how to read buret
read backwards almost
read the empty space to the hundredths place
open calorimeter with energy of chip and absorbance of water
heat absorbed by water too low
energy produced by chip is too low
in concentration absorbance graph the x and y values are
x= concentration
y= absorbance
Cu reaction and explain
3Cu (s) + 8HNO3 (aq) -> 3Cu(NO3)2 (aq) + 2NO2 (g) + 4H2O (L)
Cu is oxidized from 0 to 2+ (losing e-) so it is an oxidation reaction
q=mcdeltaT
Mass in grams
heat in Joules
heat capacity in J/g
Temp in degrees C
how could one mess up moles in gaismetry
Using a higher concentration of the reactant than specified in the procedure would cause a student to overestimate the number of moles produced
PV=
nRT (R is ideal gas content) usually 0.0821atm/mol
