What is the numerical quantity of the ratio rest energy/rest mass?

9 × 10¹⁶ m²/s² (square of speed of light in vacuum)

Explanation:

Einsteins' energy mass relation:

E = mc²

Where, E is energy, m is mass and c is the speed of light.

The ratio of rest energy to rest mass:

speed of light in vacuum is 3 × 10⁸ m/s

Hence, the numerical quantity of the ratio of rest energy/ rest mass = (3 × 10⁸ m/s)² = 9 × 10¹⁶ m²/s².

  the grams     of oxygen gas   that can be produced     is 20.6   grams of o₂

calculation

2liclo₃ →   2 licl + 3 o₂

step 1:   find the moles of liclo₃

moles = mass÷ molar mass

from periodic table the molar mass of liclo₃ =6.9 +35.5   +(16 x3) =90.4 g/mol

moles=38.7 g÷90.4 g/mol=0.4281   moles

step 2:   use the   mole ratio   to calculate the moles of o2

from equation above, liclo₃: o₂   is 2: 3  

therefore the moles of   o₂=0.4281 moles x3/2 =0.6422   moles

step 3: find mass   of o₂

mass= moles x molar mass

from periodic table the   molar mass of   o₂ = 16 x2= 32 g/mol

mass=0.6422   moles   x   32 g/mol = 20.6 grams of o₂