from a calorimeter experiment I got this calculation:
Cm=30g(4.184 J/g(Celsius))(24 Celsius-20.8Celsius)/-25g(24 Celsius-99.6 Celsius)
gives
Cm= .107 J/g(Celsius)
I have the answer here above, but when I calculate it I get different answers could someone please explain how I can get .107 J/g(Celsius) I don't understand how. Thank you!
My answer is 0.212
Thank you! Yes that's what I get too when I calculate it, but i don't know why my professor has .107 as his answer on the notes I will double check with him about it than.Thank you :)
To calculate the specific heat capacity (Cm), we need to use the formula:
Cm = (Q / mΔT)
where:
- Q is the heat transferred
- m is the mass of the substance being heated or cooled
- ΔT is the change in temperature
In your calculation, you have the following values:
- Mass (m) = 30 g
- Heat transferred (Q) = 25 g * (24 °C - 99.6 °C)
- Temperature change (ΔT) = 24 °C - 20.8 °C
Now, let's calculate the heat transferred (Q):
Q = 25 g * (24 °C - 99.6 °C)
Q = 25 g * (-75.6 °C)
Q = -1890 J
Now, plug in the values into the formula for specific heat capacity (Cm):
Cm = (-1890 J) / (30 g * (24 °C - 20.8 °C))
Cm = -1890 J / (30 g * 3.2 °C)
Cm ≈ -19.7 J/g(°C)
It seems there may be an error in the calculation, resulting in a different value for Cm. Please check your calculations again, to determine if there was any mistake made in the numeric computations.
To understand how to get the value of 0.107 J/g(°Celsius), let's go through the calculations step by step.
In a calorimeter experiment, the heat capacity of the calorimeter, Cm, can be determined using the formula:
Cm = (mass of water × specific heat capacity of water × change in temperature of water) / (mass of substance × change in temperature of substance)
Given:
Mass of water (mH2O) = 30g
Specific heat capacity of water (cH2O) = 4.184 J/g°C
Change in temperature of water (ΔTwater) = 24°C - 20.8°C = 3.2°C
Mass of substance (msubstance) = 25g
Change in temperature of substance (ΔTsubstance) = 24°C - 99.6°C = -75.6°C
Plugging these values into the formula, we get:
Cm = (30g × 4.184 J/g°C × 3.2°C) / (25g × -75.6°C)
Now, let's calculate each part separately.
In the numerator:
30g × 4.184 J/g°C × 3.2°C = 401.28 J
In the denominator:
25g × -75.6°C = -1890 J
Finally, we can calculate the heat capacity:
Cm = 401.28 J / -1890 J ≈ -0.2127 J/g°C
It seems like there might be an error in your calculations or the given values. The negative sign indicates a reverse change in temperature and can be ignored for the purpose of magnitude comparison. However, the expected value of the heat capacity is positive due to the convention of using magnitude.
To get a positive value, we can drop the negative sign and round the result to three decimal places:
Cm ≈ 0.213 J/g°C
The value you were given, 0.107 J/g°C, is half of the correct value, so it seems like there may have been an error in the calculation or data entry. Please double-check the calculations and make sure the given data is correct to obtain the accurate value.