Question

Although it is not usually used, Einstein's equation, E =mc² applies to chemical reactions as well as nuclear reactions. A combustion reaction released 45.0 kJ when one gram of a reactant was burned. How much of this mass was lost in the process? Report your answer to 3 significant figures. 1 joule = 1 kilogram-meter²/second²

Options:

a) 6.86 x 10⁻¹² kg
b) 4.50 x 10⁻¹¹ kg
c) 4.92 x 10⁻¹¹ kg
d) 9.01 x 10⁻¹¹ kg

Answer 1

The mass lost in the chemical reaction is 5.00 x 10^-14 kg.

Step-by-step explanation:

Einstein's equation, E=mc², can be used to calculate the amount of mass lost in a chemical reaction. The equation states that energy (E) is equal to the mass (m) times the speed of light squared (c²). In this case, we have the energy released (45.0 kJ) and we need to determine the mass lost. Rearranging the equation, we have m = E/(c²). Plugging in the values, we get m = 45.0 kJ / (3.00 x 10^8 m/s)² = 45.0 x 10^3 J / (9.00 x 10^16 m²/s²) = 5.00 x 10^-14 kg.