Anoble gas is placed in a 10.0 liter container. the noble gas has a mass of 25.25 g, the pressure is 3.05 atm, and the temperature is 24°c. find the molar mass and symbol for the gas.

The problem can be solved using Ideal Gas Equation.

The equation is given below.

Step 1 : Calculate moles of the gas (n)

Where P = pressure of the gas in atm = 3.05 atm

V = Volume of the gas in Liters = 10.0 L

n = number of moles of the gas

R = Gas constant = 0.08206 L-atm/mol-K

T = Temperature of the gas in Kelvin

To convert T from Celsius to Kelvin unit, we add 273

Hence we have T = 24 + 273 = 297 K

Let us plug in the above values in ideal gas equation

... Unit K gets cancelled

Number of moles of gas are 1.25

Step 2 : Find molar mass using mol value

Mole and molar mass can be related to each other by the following expression

The mass of the gas is given as 25.25 g

moles (n) = 1.25 mol

After plugging the values we get,

Molar mass =

Molar mass =

Molar mass of the gas is 20.2 /mol

Step 3 : Find identity of the gas using periodic table

From the periodic table , we can see that noble gas Neon has molar mass 20.18g/mol .

Hence the given gas is Neon which is represented by the symbol is "Ne"

20.2 g/mol; Ne

Explanation:

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.