Specific Heat Capacity Calculation in Chemistry Experiment
What can the chemist report for the specific heat capacity of the substance?
A chemist carefully measures the amount of heat needed to raise the temperature of a 157.0 mg sample of a pure substance from 25.8 °C to 32.9 °C. The experiment shows that 4.7 J of heat are needed. What can the chemist report for the specific heat capacity of the substance? Round your answer to 2 significant digits.
The specific heat capacity of the substance is approximately 4.2 J/(g°C).
To calculate the specific heat capacity (c) of the substance, we can use the formula: Q = mcΔT
Where:
- Q is the heat energy absorbed or released (in joules).
- m is the mass of the substance (in grams).
- c is the specific heat capacity (in J/(g°C) or J/(g*K)).
- ΔT is the change in temperature (in °C or K).
First, let's convert the mass from milligrams to grams: Mass = 157.0 mg = 0.1570 g
Now, plug in the values:
- Q = 4.7 J (heat energy)
- m = 0.1570 g (mass)
- ΔT = (32.9 °C - 25.8 °C) = 7.1 °C
Now, we can solve for c: c = Q / (mΔT)
c = 4.7 J / (0.1570 g * 7.1 °C)
Rounded to two significant digits, the specific heat capacity of the substance is approximately 4.2 J/(g°C).
The specific heat capacity (c) of a substance is the quantity of heat required to raise the temperature of 1 gram of the substance by 1 degree Celsius (or 1 Kelvin).
In this case, the experiment shows that a certain amount of heat (given in the question) is needed to raise the temperature of the substance. To find the specific heat capacity, we can use the formula: c = q / (m * ΔT)
Where:
c is the specific heat capacity
q is the amount of heat
m is the mass of the substance
ΔT is the change in temperature
Specific heat capacity is an essential property in chemistry, as it helps determine the amount of heat required for temperature changes in substances. By calculating specific heat capacity, chemists can better understand the thermal characteristics of materials and their behavior under different conditions.