An electric furnace is to melt 40 kg of aluminium/hour. the initial temperature of aluminium is 32°c. given that aluminium has specific heat capacity 950 j/kg k melting point 680*c, latent heat of fusion 450 kj/kg, the efficiency of furnace is 85% and cost of energy is 20 cents/kwhr calculate: (a) power required (b) the cost of operating the furnace for 30 hours

Part a)

P = 13.93 kW

Part b)

R = 8357.6 Cents

Explanation:

Part A)

heat required to melt the aluminium is given by

here we have

Since this is the amount of aluminium per hour

so power required to melt is given by

Since the efficiency is 85% so actual power required will be

Part B)

Total energy consumed by the furnace for 30 hours

now the total cost of energy consumption is given as

  1.the balanced   chemical equation is as below

cu +   2 ag(no)₃ → cu(no₃)₂   +2 ag

2.the   much silver   produced   is   50.9 g

step 1: find the   moles of cu

moles =   mass÷   molar mass

  from periodic table the molar mass of cu = 63.5 g/mol

moles is therefore = 15.00 g÷ 63.5 g/mol = 0.236   moles

step 2: use the mole ratio to determine the   moles of ag

from equation above   cu: ag   is 1: 2

therefore the moles of ag   =0.236   moles   x 2/1 =0.472   moles

step 3: find the mass   of ag

mass = moles x molar mass

from periodic table   the molar mass of ag =107.87 g/mol

mass   = 0.472   moles x 107.87 g/mol = 50.9 g

3.   the   much   silver   collected worth is   1.797 oz

  convert   50.9 g   to oz

that is   1 gram = 0.0353 oz

          50.9 grams =?   oz

by cross multiplication

={(50.9 grams x 0.0353 oz) / 1   gram}   =1.797 oz