Experimental Design Flashcards
what is the apparatus used to measure mass?
electronic balance
what is the smallest division of an electronic balance?
0.01g
values for the electronic balance should be recorded to the nearest __?
0.01g
what is the apparatus used to measure time?
digital stopwatch
what is the smallest division of a digital stopwatch?
0.01s
values for the digital stopwatch should be recorded to the nearest __?
0.1/1s (depends on experiment; to account for human reaction time)
what is the apparatus used to measure temperature?
thermometer
what is the smallest division of a thermometer?
1°C
values for the thermometer should be recorded to the nearest __?
0.5°C
what factors are considered when choosing apparatus for measuting volume?
1) volume to be measured
2) precision of measurement
what are 4 apparatuses for volume?
1) beaker
2) measuring cylinder
3) burette
4) pipette
what is a beaker used for?
to measure approximate volumes only
what is a beaker’s capacity and smallest division?
100cm³; 25cm³
what is a measuring cylinder’s capacity, smallest division and precision?
100.0cm³; 1cm³; 0.5cm³
what is a burette’s capacity, smallest division and precision?
50.00cm³; 0.1cm³; 0.05cm³
what is a pipette used for?
measuring fixed volumes only (25cm³)
how do you read the reading of a convex meniscus?
read scale at top of meniscus (e.g. mercury)
how do you read the reading of a concave meniscus?
read scale at the bottom of the meniscus
what are factors to consider when choosing methods of gas collection?
1) solubility of gas in water
2) density of gas compared to air (~30)
*best method would allow for most volume to be collected
what are the 4 methods of gas collection?
1) downward delivery
2) upward delivery
3) water displacement
4) gas syringe
describe the use of downward delivery
used for gases soluble in water, denser than air
describe the use of upward delivery
used for gases soluble in water, less dense than air
describe the use of water displacement
used for gases slightly insoluble/insoluble in water (e.g. hydrogen, oxygen)
describe the use of gas syringe
collects most gases to measure their volume
what is the method for drying acidic gases?
drying agent: concentrated sulfuric acid
delivery tube for moist gas in should be submerged in drying agent, delivery tube for dry gas out should be above the drying agent
not used for drying alkaline gases (e.g. ammonia) as neutralisation would occur (can be used to eliminate gases from a mixture of gases)
what is the method for drying alkaline gases?
drying agent: calcium oxide (quicklime)
used mainly to dry ammonia gas
not used for drying acidic gases (e.g. carbon dioxide) as neutralisation would occur (can be used to eliminate gases from a mixture of gases)
what is the method for drying neutral gases?
drying agent: fused calcium oxide
fused calcium oxide can dry most gases except ammonia (calcium oxide would react to ammonia gas)
neutral gases can be dried using acidic, alkaline or neutral drying agents
what is the nature of hydrogen (H₂)?
neutral
what is the nature of oxygen (O₂)?
neutral
what is the nature of carbon monoxide (CO)?
neutral
what is the nature of carbon dioxide (CO₂)?
acidic
what is the nature of chlorine (Cl₂)?
acidic
what is the nature of hydrogen chloride (HCl)?
acidic
what is the nature of sulfur dioxide (SO₂)?
acidic
what is the nature of sulfur trioxide (SO₃)?
acidic
what is the nature of ammonia (NH₃)?
alkaline
what is the solubility of hydrogen (H₂) in water?
insoluble
what is the solubility of oxygen (O₂) in water?
slightly soluble
what is the solubility of carbon monoxide (CO) in water?
insoluble
what is the solubility of carbon dioxide (CO₂) in water?
slightly soluble
what is the solubility of chlorine (Cl₂) in water?
soluble
what is the solubility of hydrogen chloride (HCl) in water?
very soluble
what is the solubility of sulfur dioxide (SO₂) in water?
very soluble
what is the solubility of sulfur trioxide (SO₃) in water?
very soluble
what is the solubility of ammonia (NH₃) in water?
very soluble
what is the density of hydrogen (H₂) relative to air?
less dense than air
what is the density of oxygen (O₂) relative to air?
about the same (slightly denser)
what is the density of carbon monoxide (CO) relative to air?
slightly less dense than air
what is the density of carbon dioxide (CO₂) relative to air?
denser than air
what is the density of chlorine (Cl₂) relative to air?
denser than air
what is the density of hydrogen chloride (HCl) relative to air?
denser than air
what is the density of sulfur dioxide (SO₂) relative to air?
denser than air
what is the density of sulfur trioxide (SO₃) relative to air?
denser than air
what is the density of ammonia (NH₃) relative to air?
less dense than air
