In the construction of bridges and sky scrapers, gaps must be left between adjoining steel beams to allow for expansion and construction of the metal due to heating and cooling. The temperature of a sample of iron with a mass of 20.0 grams changed doom 60.0 C to 35.0c. How many joules of heat were released? A. 200 joules B. 225 joules C. 152 joules d. 346 joules

Q = - 225 J

Explanation:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m. c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Given dа ta:

Mass of iron = 20 g

Initial temperature = 60 °C

Final temperature = 35 °C

Heat released = ?

Solution:

Q = m. c. ΔT

Specific heat of iron = 0.46 j/g. °C

ΔT = 35 °C - 60 °C

ΔT = - 25 °C

Q = 20 g * 0.450 j/g. °C * - 25 °C

Q = - 225 J