[BJB]

Hi everyone ,,

This my first sharing in with I hope you accepting me as a friend .

Now,

The main lesson is The Ideal Gas Equation from 'Chemistry by Chang'

I have two question and I hope that I get the inforemation from you

1
How to caculate the molar mass of a gas?

actually, I didn't know how to solve this:

* At 741 torr and 44°c, 7.10g of a gas occupy a volume of 5.40L. What is the molar mass of the gas?

2
the second one I didn't understand what is it?
* Dry ice is solidcarbon dioxide. A 0.050g sample of dry ice is placed in an evacuated 4.6L vessel at 30°c. Calculate the oressure inside the vessel after all the dry ice has been converted to CO2 gas?


I hope that you understood what I have said to you and answering me Quickly

good luck

[Borek]

Please read forum rules. You have to show your attempts at solving the question to receive help. This is a forum policy.

At 741 torr and 44°c, 7.10g of a gas occupy a volume of 5.40L. What is the molar mass of the gas?

How many moles of the gas? Can you calculate molar mass knowing mass and number of moles in sample?

Dry ice is solidcarbon dioxide. A 0.050g sample of dry ice is placed in an evacuated 4.6L vessel at 30°c. Calculate the oressure inside the vessel after all the dry ice has been converted to CO2 gas?

This is direct application of PV=nRT, you are given all necessary information. How many moles of carbon dioxide?

[BJB]

Thank you Borek ,,

I got the answer:

1
Q:
P= 741 torr = 741 mmHg
V= 5.4 L
T= 44 °c
wt= 7.10 g

A:
P in atm * V in L = nRT

741/760 * 5.4 = wt/M * 0.082 * (44+273) =

2
Q:
CO2
wt = 0.05 g
V  = 4.6 L
T  = 30 °c

A:

P.V = nRT
n = 0.05/44> the molecule wight of CO2
P = 0.05*0.082*(30+273)/44*4.6 = 6.14*10^-3 atm


thank you