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A 9.0 g of a mysterious substance was heated from 23.0°C to 85.0°C using 127 J of heat. To identify the substance we need to know the specific heat capacity of it. What is the mysterious substance's specific heat

capacity?
Which of the following choice identifies correctly the setup of the variables' positions within the formula?
а. 127 ) = (9.0 g) (85 °C - 23.0°C)
b. 127) = (85 °C) (9.0 g - 23.0°C)
c. 85° = (9.0 g) (127] - 23.0°C)
d. 9.0 g = (127)) (85 °C - 23.0 °C)

1 Answer

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Final answer:

The specific heat capacity of the substance is calculated using the formula q = mc∆T, with the given heat q, mass m, and temperature change ∆T. After substituting the values into the formula, the specific heat capacity is found to be approximately 0.230 J/g°C. This value can be compared to a reference table to identify the substance.

Step-by-step explanation:

The specific heat capacity of a substance is the amount of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius. To calculate the specific heat capacity (c) of the mysterious substance, we use the formula q = mc∆T, where q is the heat in joules, m is the mass in grams, and ∆T is the change in temperature in degrees Celsius.

From the given information, we have m = 9.0 g, the change in temperature ∆T is 85.0°C - 23.0°C = 62.0°C, and q = 127 J. By rearranging the formula to solve for c, c = q / (m∆T), and substituting the known values, we find that the specific heat capacity is c = 127 J / (9.0 g × 62.0°C).

Thus, the specific heat capacity of the mysterious substance is approximately 0.230 J/g°C. To identify the substance, one would compare this calculated specific heat capacity with values in a reference table such as Table 9.1, given that such a table is available, which is implied by the data provided.

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