Discover Specific Heat Calculations for Carbon and Unknown Substance

[lynn0808]

a.Determine the amount of energy to raise the temperature of 18 kg of carbon from -5^0C to 17^0C.

B. 200g of a certain substance absorbs 7320 J of energy and experienced a temperature rise from 5^0C to 30^0C. By calcuating its "C" value, identify as near as possible, the unknown substance.


delta t= 17-5=12^0C. M=18kg
C=709j/kg
energy=cXmXdelta t
709J/kg.K X 18kg X12K
energy=3.28 KJ
=3.3 X10^2?

Im not sure what I am doing. Need help

 

[GCT]

a.Determine the amount of energy to raise the temperature of 18 kg of carbon from -5^0C to 17^0C.

B. 200g of a certain substance absorbs 7320 J of energy and experienced a temperature rise from 5^0C to 30^0C. By calcuating its "C" value, identify as near as possible, the unknown substance.


delta t= 17-5=12^0C. M=18kg
C=709j/kg
energy=cXmXdelta t
709J/kg.K X 18kg X12K
energy=3.28 KJ
=3.3 X10^2?

Im not sure what I am doing. Need help

First seems fine , your same strategy needs to be applied to the second question.

 

[Blueshift5]

.

A. To determine the amount of energy required to raise the temperature of 18 kg of carbon, we can use the formula Q = mcΔT, where Q is the amount of energy, m is the mass of the substance, c is the specific heat capacity, and ΔT is the change in temperature. In this case, we have a mass of 18 kg, a specific heat capacity of c = 709 J/kg.K, and a temperature change of ΔT = 12^0C. Plugging these values into the formula, we get:

Q = (709 J/kg.K)(18 kg)(12 K) = 152,616 J = 152.6 kJ

Therefore, it would take 152.6 kJ of energy to raise the temperature of 18 kg of carbon from -5^0C to 17^0C.

B. To identify the unknown substance, we can use the same formula Q = mcΔT, but rearranged to solve for c. We know that Q = 7320 J, m = 200 g, and ΔT = 30^0C - 5^0C = 25^0C. Plugging these values into the formula, we get:

7320 J = (c)(200 g)(25 K)

Solving for c, we get c = 7320 J / (200 g)(25 K) = 1.464 J/g.K

Based on the specific heat capacity table, this value is closest to the specific heat capacity of aluminum (c = 0.903 J/g.K). Therefore, the unknown substance is likely to be aluminum. However, we cannot say for certain without more information.