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An unknown substance has a mass of 14.5 g. When the substance absorbs 1.305x10² J of heat, the temperature of the substance is raised from 25.0C to 45.0C. What is the most likely identity of the substance?

User MUHAHA
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Final answer:

The specific heat of the unknown substance is 0.45 J/g°C. Without a reference table, the substance cannot be identified, but it is not water due to the substantially lower specific heat.

Step-by-step explanation:

To determine the specific heat of the substance, we can use the formula:
Q = mcΔT, where Q is the energy in joules, m is the mass in grams, c is the specific heat capacity in J/g°C, and ΔT is the change in temperature in degrees Celsius.

Given that the substance absorbs 1.305x10² J of heat to raise its temperature from 25.0°C to 45.0°C and that the mass of the substance is 14.5 g, we can rearrange the formula to solve for c:
c = Q / (mΔT).

The change in temperature (ΔT) is 45.0°C - 25.0°C = 20.0°C.
Therefore, c = 1.305x10² J / (14.5 g * 20.0°C) = 0.45 J/g°C.

Without Table 9.1, we can't definitively identify the substance; however, with the specific heat close to that of water (4.18 J/g°C), it is likely not water because the calculated specific heat is much lower. We can compare it to known specific heat values of common substances to make an educated guess.

User Brick Yang
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