Lab practical!!

Question 1

density of displacement=

Answer 1

mass of object / volume of displacement

Question 2

percent yield=

Answer 2

actual / theoretical times 100

Question 3

what happens to the validity of a calorimetry experiment that is open (not closed)

Answer 3

-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

Question 4

Pressure (P) of total =

Answer 4

pressure atm (atmosphere)

Question 5

P tot=

Answer 5

P of carbon dioxide gas + P water vapor + Δh/13.6

Question 6

P atm=

Answer 6

P carbon dioxide gas + P water vapor + Δh/13.6

Question 7

P carbon dioxide gas=

Answer 7

P atm - P water vapor - Δh/13.6

Question 8

E=

Answer 8

hc/ lamda (wavelength)

Question 9

when reading a graduated cylinder

Answer 9

read from the bottom of the meniscus
it has 3 sig figs so ONE decimal place

Question 10

filtration (from book)

Answer 10

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

Question 11

dislillation

Answer 11

process of separating components from liquid mixtures through vaporization condensation based on their different boiling points

Question 12

difference between gravity filtration and vacuum filtration

Answer 12

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

Question 13

cathode (from google)

Answer 13

species gains electrons
Cu2(+) (aq) + 2e- = Cu(s)

Question 14

anode (from google)

Answer 14

oxidation reaction that releases reactions or loses electrons
Zn(s) = Zn2+ (aq) + (2e-)

Question 15

what are the steps in the copper cycle

Answer 15

(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

Question 16

the first step in the copper cycle is a

Answer 16

redox reaction

Question 17

when measuring the density of a rod

Answer 17

-weigh the rod
-use displacement (final-initial change in vol)
-do grams change to get grams over ml
-so mass/vol

Question 18

sig figs in graduated cylinder

Answer 18

just to the tenths place

Question 19

sig figs on a ruler

Answer 19

just to the tenths place

Question 20

sig figs in a buret

Answer 20

to the hundredths place (2 decimal places)

Question 21

how to read buret

Answer 21

read backwards almost
read the empty space to the hundredths place

Question 22

open calorimeter with energy of chip and absorbance of water

Answer 22

heat absorbed by water too low
energy produced by chip is too low

Question 23

in concentration absorbance graph the x and y values are

Answer 23

x= concentration
y= absorbance

Question 24

Cu reaction and explain

Answer 24

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

Question 25

q=mcdeltaT

Answer 25

Mass in grams
heat in Joules
heat capacity in J/g
Temp in degrees C

Question 26

how could one mess up moles in gaismetry

Answer 26

Using a higher concentration of the reactant than specified in the procedure would cause a student to overestimate the number of moles produced

Question 27

PV=

Answer 27

nRT (R is ideal gas content) usually 0.0821atm/mol