How much heat is absorbed by a 47g iron skillet when its temperature rises from 12oc to 20oc?

Answer

169.2 J

Explanation

Given in the question,

mass of iron = 47g

specific heat capacity of iron = 0.450 (J/g 0C)

initial temperature = 12° C

final temperature = 20° C

The energy q needed to increase an object of mass m and specific heat capacity c by a temperature θ is given by:

q = mcΔt

q = 47(0.45)(20-12)

q = 169.2 J

the body's situation won't change the forces are equal opposit and on the same body

  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