Unit 3.3 Flashcards
what would the structure be of a solid crystalline
three-dimensional
what would you call it when a solid does not have a regular, orderly arrangement
amorphous
what formula do you use when
“calculate the value of the molar mass of the known gas”
PV=nRT
interpret PV=nRT
pressurevolume=moles.0821*temp
why does pressure decrease as temp decreases
bc as temp decreases, theres less bouncing on the walls so the pressure is decreasing
molar mass=
g of substance/moles
percent error formula
actual-theoretical/ actual *100
justify why there was a percent error
1-the flask was incompletely flushed with CO2(g), resulting in some dry air remaining in the flask
the dry air has less mass than CO2 so that’s why our number is less than it should be
Justify why there was a percent error
2-the temp of the air was 23C but the temp of the CO2 was lower than the reported 23C
incorrect bc if the temp decreased that means the volume decreases so density increases which also means the mass would increase. The mass of the gas would be too high
justify why there was a percent error:
1- The flask was incompletely flushed with CO2(g), resulting in some dry air remaining in the flask
correct bc dry air has less mass thatn CO2 so thats why the theortical number is less than it should be
as temp decreases, pressure…
decreases and vise versa
how could you tell if the volume of a rigid flask is 843mL at 23 degrees C without calculations
pour to flask into a 1000mL granulated cylinder and record the volume to see if you were correct
mm equation
mm=DRT/P
steps to “find partial pressure” when given total torr
1) find moles first
1st element:
g/mass=mols
2nd element:
g/mass=mols
2) add both for total moles
3) divide each individual mol/ total moles
=that is called P
4) each: P*element=P * total torr
Steps to find partial pressure when not given total
1) find moles for both elements
g/mass
add those together to get total pressure
2) so PV=nRT plug in total pressure for n
3) do individual PV=nRT and divide that by total
find g in of one element from a mixture steps
1) find moles for element with given grams
g/mass
2) find moles for other element using PV=nRT
3)subtract given-unkown
4) convert moles to g
“find the mole fraction”
moles/total moles
just do the partial pressure/total pressure
How to convert Temp to Kelvin
T+273.15
How to convert atm to mmHg
P*760
How to convert mmHg to atm
/760
What is the constant R for atm
.0821
What is the constant R for tarr
62.36
The stopcock connecting a 4.43 L bulb containing methane gas at a pressure of 7.28 atm, and a 5.10 L bulb containing carbon dioxide gas at a pressure of 2.46 atm, is opened and the gases are allowed to mix. Assuming that the temperature remains constant, the final pressure in the system is
atm.
what formula would you use to answer this question
Ptotal=(p1v1)+(p2v2) / (v1+v2)
A helium-filled weather balloon has a volume of 703 L at 18.9°C and 759 mmHg. It is released and rises to an altitude of 2.40 km, where the pressure is 627 mmHg and the temperature is 3.9°C.
The volume of the balloon at this altitude is ____ L
what formula would you use to answer this question
(p1v1) (p2v2)
———- = ———–
T1 T2