A 100 g piece of ice (solid water) at 0 °C melted to liquid water at 75.5 °C. If all the heat came from propane (C3H8) combustion, how many grams of propane Molar mass is 44.1'
To calculate the amount of propane needed to melt the ice, we first need to find out how much heat is required to melt the ice.
The specific heat capacity of ice is 2.09 J/g°C, which means it takes 2.09 Joules of heat to raise the temperature of 1 gram of ice by 1 degree Celsius.
The heat required to raise the temperature of the ice from 0°C to its melting point is:
Q = (mass of ice) × (specific heat capacity of ice) × (change in temperature)
= 100 g × 2.09 J/g°C × (0°C - 0°C) = 0 J
Next, we need to calculate the heat required to melt the ice. The heat of fusion for ice is 334 J/g, which means it takes 334 Joules of heat to melt 1 gram of ice at its melting point.
The heat required to melt the ice is:
Q = (mass of ice) × (heat of fusion of ice)
= 100 g × 334 J/g = 33400 J
Now, we can calculate the amount of propane needed to provide this amount of heat.
The heat generated by the combustion of propane can be determined using the equation:
Q = (mass of propane) × (heat of combustion of propane)
Re-arranging this equation, we can calculate the mass of propane required:
(mass of propane) = Q / (heat of combustion of propane)
The heat of combustion of propane is given as the energy released when 1 mole of propane is combusted, which is 2220 kJ/mol (or 2220 × 10^3 J/mol).
To convert the heat required to melt the ice from Joules to kilojoules:
33400 J = 33.4 kJ
Now, we can calculate the amount of propane needed:
(mass of propane) = (33.4 kJ) / (2220 kJ/mol)
= (33.4 × 10^3 J) / (2220 × 10^3 J/mol)
= 0.015 moles of propane
Finally, we can convert moles of propane to grams using its molar mass:
(mass of propane) = (0.015 moles) × (44.1 g/mol)
= 0.6615 grams
Therefore, approximately 0.66 grams of propane are needed to melt the 100 g piece of ice.
Heatpropane=heatin water
massP*Heatcombusion=Hf*100g+100(cwater)(75.5-0)
so figure the mass.
when looking up the heat of combustion for propane, you want it in Joules/gram, if the table is in juouls/mole, you will have to convert.