In the construction of bridges and skyscrapers, gaps must be left between adjoining steel beams to allow for the expansion and contraction of the metal due to heating and cooling. The temperature of a sample of iron with a mass of 10.0g changed from 50.4oC to 25.0oC with the release of 114J heat. What is the specific heat?
To find the specific heat of iron, we can use the formula:
Q = mcΔT
where:
Q = heat released (in J)
m = mass of the sample (in g)
c = specific heat (in J/g°C)
ΔT = change in temperature (in °C)
In this case, we know:
Q = 114 J
m = 10.0 g
ΔT = (25.0 - 50.4) °C = -25.4 °C
Plugging in the values, we can rearrange the formula to solve for c:
c = Q / (m * ΔT)
c = 114 J / (10.0 g * -25.4 °C)
c = -0.448 J/g°C
Therefore, the specific heat of iron is approximately -0.448 J/g°C.
To find the specific heat of a substance, you can use the formula:
Heat released (Q) = Mass (m) x Specific heat (C) x Change in temperature (ΔT)
In this case, we are given the mass of the iron (10.0g), the change in temperature (50.4oC - 25.0oC = 25.4oC), and the heat released (114J).
To find the specific heat (C), we rearrange the formula:
C = Q / (m x ΔT)
Plugging in the given values, we have:
C = 114J / (10.0g x 25.4oC)
To get the specific heat in J/g·oC, divide both sides of the equation by grams and degrees Celsius:
C = (114J / (10.0g x 25.4oC)) * (1g / 1g) * (1oC / 1.0oC)
C ≈ 0.448 J/g·oC
Therefore, the specific heat of the iron is approximately 0.448 J/g·oC.
q = mass iron x specific heat iron x (Tfinal-Tinitial)
q = 114