1. explain the change of state from solid dry ice to carbon dioxide gas. 2. the motion of the particles in dry ice and carbon dioxide gas. 3. explain how the original mass of dry ice compares with the mass of carbon dioxide gas.

1. Since the solid carbon dioxide never become liquid on melting under normal pressure. Thus through the process of sublimation, the solid carbon dioxide changes to gas

2. The molecules in dry ice, are in caged like structure just as the normal water ice but as it melts, the CO2 molecules having high affinity for gaseous state converts into a gas.

3. Dry ice is heavier than its gaseous form. Density of dry ice = 97.6 lb/cu.ft.

Density of carbon dioxide gas = 0.1144 lb/cu.ft.

With higher density and a fixed volume, mass of dry ice is higher than the CO2 gas

  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