Question

A 4.21 kg lead billet is to be melted for a casting operation. Lead has a melting point of 328°C, a specific heat capacity of 128 J/(kg·°C), and a latent heat of fusion of 23,200 J/kg. (use correct number of significant figures in your final answer.)

(a) Calculate the amount of heat required to heat the lead from a starting temperature of 21.7°C to its melting point of 328°C.

(b) Calculate the amount of heat needed to melt the lead brick once it reaches 328°C.

Answer #1

A 2.03-g lead bullet traveling at 508 m/s strikes a target,
converting its kinetic energy into thermal energy. Its initial
temperature is 40.0°C. The specific heat is 128 J/(kg · °C), latent
heat of fusion is 24.5 kJ/kg, and the melting point of lead is
327°C.
(a) Find the available kinetic energy of the bullet.
J
(b) Find the heat required to melt the bullet.
J

Answer the following questions:
a) A sample of lead with a mass of 1.45 kg is heated until it
reaches its melting point at 330 C. The lead is then heated further
until it has entirely melted. During this process, the lead absorbs
a total of 4.46 * 10 ^ 4 J as heat. What is the temperature at
which the lead is initially heated?
b) Gallium melts at 29.78 C, a temperature that can be achieved
by the atmosphere...

A home melting pot is used for a metal casting hobby. At the end
of a work period, the pot contains 608 grams of lead at 439°C. How
much energy will be released as the molten metal cools, solidifies,
and cools further to room temperature, 22°C? Data for lead at 1
atm: Melting point = 328°C Specific heat liquid = 0.138 J/g ⋅ °C
Specific heat solid = 0.130 J/g ⋅ °C Heat of fusion = 23.0 J/g
__J

Some gun fanciers make their own bullets, which involves melting
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A 60 kg block of ice begins at -60 degrees the specific heat of
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10^5 and the latent heat of vaporization is 2.3 x 10^6 J/kg. How
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How much energy is required to heat the ice from -50C to the
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How much energy is required to...

The melting point of aluminum is 660°C, its latent heat
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An ice cube of mass 0.041 kg and temperature -13 ∘C is heated
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Estimate the speed that a lead bullet must have in order that it
melts completely when it strikes a target. Assume that all the
bullet’s kinetic energy goes into heat and that the bullet is
initially at 20oC. The specific heat capacity of lead is 130 J /
(kg oC), its melting point is at 327oC its latent heat of fusion is
24.5 kJ/kg.

A 0.033 kg glass (with c = 840 J/kg oC) contains 0.281 of
lemonade which, due to the sugar content, has a specific heat of
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allowing it to completely melt the final equilibrium temperature of
the glass of lemonade is found to be 2.9 oC. intial temperature is
0.
(a) Calculate the initial temperature of the lemonade and glass.
oC
Note the following data for ice/water: specific...

(28.1) Let’s reconsider the 23.5 kg of silver that we warmed and
then melted in PS#14. (a) In warming the silver its entropy [Choose
One:] increased remained constant decreased . (b) In melting the
silver its entropy [Choose One:] increased remained constant
decreased . (c) By what amount did the entropy of the silver change
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