(PLEASE HELP 20 POINTS ON A TEST) 4.2 moles of an unknown gas at a pressure of 5.5 atm has a volume of 12.0 L.
What is the temperature?

191.4K

Explanation:

Using the ideal gas law equation as follows:

PV = nRT

Where;

P = pressure (atm)

V = volume (L)

n = number of moles (mol)

R = gas law constant (0.0821 Latm/molK)

T = temperature (K)

According to the information provided in this question:

n = 4.2moles

P = 5.5atm

V = 12.0 L

T = ?

Using PV = nRT

5.5 × 12 = 4.2 × 0.0821 × T

66 = 0.345 T

T = 66/0.345

T = 191.4K

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation:

a is the answer to this question

explanation: