Math Problem Statement

A 122 g piece of metal is heated to 292 ∘C and dropped into 84.5 g of water at 26.0 ∘C . The metal and water come to the same temperature of 57.5 ∘C What is the specific heat of the metal?

Solution

We can use the principle of conservation of energy, which states that the heat lost by the metal is equal to the heat gained by the water:

qmetal=qwaterq_{\text{metal}} = -q_{\text{water}}

Step 1: Use the Heat Transfer Formula

The heat transfer equation is:

q=mcΔTq = mc\Delta T

where:

  • qq is the heat energy (J),
  • mm is the mass (g),
  • cc is the specific heat capacity (J/g·°C),
  • ΔT\Delta T is the temperature change (°C).

Step 2: Calculate the Heat Gained by Water

The specific heat of water is cwater=4.18c_{\text{water}} = 4.18 J/g·°C. The temperature change for water is:

ΔTwater=57.5C26.0C=31.5C\Delta T_{\text{water}} = 57.5^\circ C - 26.0^\circ C = 31.5^\circ C

qwater=(84.5 g)(4.18 J/g°C)(31.5C)q_{\text{water}} = (84.5 \text{ g}) (4.18 \text{ J/g°C}) (31.5^\circ C)

qwater=11118.885 Jq_{\text{water}} = 11118.885 \text{ J}

Step 3: Calculate the Specific Heat of the Metal

The temperature change for the metal is:

ΔTmetal=57.5C292C=234.5C\Delta T_{\text{metal}} = 57.5^\circ C - 292^\circ C = -234.5^\circ C

Since the metal loses heat:

qmetal=qwaterq_{\text{metal}} = -q_{\text{water}}

(122 g)(cmetal)(234.5C)=11118.885 J(122 \text{ g}) (c_{\text{metal}}) (-234.5^\circ C) = -11118.885 \text{ J}

Solving for cmetalc_{\text{metal}}:

cmetal=11118.885122×234.5c_{\text{metal}} = \frac{11118.885}{122 \times 234.5}

cmetal0.39 J/g°Cc_{\text{metal}} \approx 0.39 \text{ J/g°C}

Final Answer:

cmetal0.39 J/g°Cc_{\text{metal}} \approx 0.39 \text{ J/g°C}

This value suggests the metal could be copper or a similar material.


Do you want a more detailed breakdown?

Related Questions:

  1. What are some common metals with a specific heat near 0.39 J/g°C?
  2. How does the specific heat of a metal relate to its atomic structure?
  3. What would happen if a different liquid (e.g., oil) was used instead of water?
  4. How does the conservation of energy apply to heat transfer problems?
  5. How would the final temperature change if the mass of water was increased?

Tip:

Always make sure the units are consistent when solving heat transfer problems!

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Math Problem Analysis

Mathematical Concepts

Heat Transfer
Specific Heat
Energy Conservation

Formulas

q = mcΔT

Theorems

Conservation of Energy

Suitable Grade Level

Grades 10-12