Aspherical iron ball 6 in. in diameter is coated with a layer of ice of uniform thickness. if the ice melts at a rate of 12 startfraction in cubed over min endfraction comma how fast is the thickness of the ice decreasing when it is 2 in. thick? how fast is the outer surface area of ice decreasing?

Explanation:

Rate of melting of ball is given as

now we know that

now we have

so we have

Diameter = 6 inch

Radius = 3 inch

Now rate of change in area is given as

so we have

  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