Plank’s equation is being used to estimate the convective heat transfer coefficient in a food being frozen in an air-blast freezer. it took a product 20 minutes to freeze in the freezer. the product is in the shape of an infinite cylinder with a diameter of 2 cm. the properties of the product are as follows: thermal conductivity of frozen material = 1.8 w/(m °c), density = 890 (kg/m3), latent heat of fusion = 260 kj/kg, and initial freezing point = -1.9 °c. the initial temperature of the product is 25°c and the air temperature is -35°c. estimate the heat transfer coefficient of the food.

  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

like poles repel so keep pushing north to north and repels funny to see this

= initial pressure

= final pressure = 2

= initial volume

= final volume = /4

= initial temperature = 20 c = 20 + 273 = 293 k

= final temperature = ?

using the equation