When 1 g of gasoline is burned in an engine, about 48 kJ of heat is produced. How much mass is lost in the process? Do you think this mass change could directly measured
Check my answer to the same question, asked by "sam" yesterday. It is among the "Related Questions" below.
To determine the mass lost during the combustion of 1 g of gasoline, we need to use the concept of energy conservation and the principle of mass-energy equivalence as described by Einstein's famous equation E=mc^2. This equation states that mass (m) can be converted into energy (E) and vice versa, with the proportionality constant being the speed of light squared (c^2).
In this case, we know the energy released during combustion (48 kJ), so we can relate it to the mass lost. Rearranging the equation, we have:
E = mc^2
m = E / c^2
Now we can substitute the given energy value into the equation, but we need to convert it to SI units (Joules):
48 kJ = 48,000 J
Using the speed of light (c ≈ 3 x 10^8 m/s) in the equation, we can calculate the mass lost:
m = 48,000 J / (3 x 10^8 m/s)^2
Simplifying the expression:
m = 48,000 J / 9 x 10^16 m^2/s^2
m ≈ 5.33 x 10^-10 kg
Therefore, approximately 5.33 x 10^-10 kg (or 0.533 ng) of mass is lost during the combustion of 1 g of gasoline.
However, directly measuring this mass change might be quite challenging in practice due to the extremely small amount involved. Precise and sensitive measurement techniques, such as mass spectrometry, would be required to detect such a minute mass change accurately.