Discover Specific Heat Calculations for Carbon and Unknown Substance

AI Thread Summary
To calculate the energy required to raise the temperature of 18 kg of carbon from -5°C to 17°C, use the formula energy = C x m x Δt, where C is the specific heat capacity (709 J/kg·K), m is mass, and Δt is the temperature change (12°C). This results in an energy requirement of approximately 3.28 kJ. For the second part, a 200g substance absorbing 7320 J with a temperature rise from 5°C to 30°C indicates a temperature change of 25°C. By calculating the specific heat capacity (C) for this substance, it can be identified based on known values for various materials. Accurate calculations for both scenarios are essential for determining the correct values.
lynn0808
Messages
9
Reaction score
0
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
 
Physics news on Phys.org
lynn0808 said:
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.
 
Thread 'Confusion regarding a chemical kinetics problem'
TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
I don't get how to argue it. i can prove: evolution is the ability to adapt, whether it's progression or regression from some point of view, so if evolution is not constant then animal generations couldn`t stay alive for a big amount of time because when climate is changing this generations die. but they dont. so evolution is constant. but its not an argument, right? how to fing arguments when i only prove it.. analytically, i guess it called that (this is indirectly related to biology, im...
Back
Top