Asample of gas has a mass of 0.673g. its volume is 250.0ml at a temperature of 83 degrees c and a pressure of 747 torr. the sample is composed of which of the following gases?
(a) xe
(b)ar
(c)so3
(d)co2
(e)h2

Explanation:

Given data:

Mass of sample = 0.673 g

Volume = 250.0 mL (0.25 L)

Temperature = 83°C (273+83= 356 k)

Pressure = 747 torr (747/760 = 0.98 atm)

Gas type = ?

Solution:

PV = nRT

n = PV/RT

n = 0.98 atm× 0.25 L / 0.0821 atm. L/mol.K × 356 k

n = 0.245 / 29.23/mol

n = 0.01 mol

Number of moles = mass/ molar mass

Molar mass = 0.673 g /  0.01 mol

Molar mass = 67.3 g/mol

molar mass of  CO2 = 44 g/mol

molar mass of  H2 = 2.016 g/mol

molar mass of  SO3 = 80.066 g/mol

molar mass of  Ar = 40 g/mol

molar mass of  Xe = 131.3 g/mol

So non of these gases are present.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-