What is the amount of heat required to raise the temperature of 200.0 g of aluminum by 10°C? (Specific heat of aluminum = -0.21 cal/g*#"^@#C)?

Question

Mateo Aguilar · Accepted Answer

Here, we're relating a few things: (1) the mass of the substance, (2) its specific heat, and (3) its temperature change with the equation,

#q = mC_sDeltaT#

Before we start, that specific heat is all kinds of wrong, they must be positive. What that is saying is that the substance is giving off energy in order to increase its temperature, that doesn't make sense! First, let's translate that to J for an easier calculation:

#(0.21cal)/(g*°C)*(4.184J)/(cal) approx (0.879J)#

#q = 200.0g*(0.879J)/(g*°C)*10°C#

#q= 175.8J approx 1.8*10^2 J#

Mateo Aguilar · Answer

undefined The amount of heat required can be calculated using the formula:

Q = m * c * ΔT

Where:
Q = heat energy (calories)
m = mass of the substance (grams)
c = specific heat capacity of the substance (cal/g°C)
ΔT = change in temperature (°C)

Substituting the given values:

Q = 200.0 g * -0.21 cal/g°C * 10°C

Q = -420 cal