How many moles are equal to 157.8g of CaCl2?

Explanation:

K: 157.8 g CaCl2

U: ? mol CaCl2

1Ca = 1(40.08) = 40.08

2 Cl = 2(35.45) =+70.90

110.98

157.8 g CaCl2 1 mol CaCl2

x

1 mol CaCl2 110.98 g CaCl2

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: