Answer to Question #127829 in General Chemistry for Hannah Ruth

Question

A Chemical reaction releases 350 kJ of energy. A joule (symbol J) is the unit of energy in the SI system of measurement. How much mass, in grams, was lost when this chemical reaction occurred? Hint: Use Einstein‘s equation E=mc^2. Use consistent SI units. If you substitute energy in joules and the velocity of light as 3.00*10^8 m/s, Your answer will come out in kilograms.

Answer 1

350 kJ = 3.5*10⁵ J

From Einstein's equation,

m = E / c² = 3.5*10⁵ J / (3.00*10⁸ m/s)² = 3.9*10^-12 kg = 3.9*10^-9 g

Answer: 3.9*10^-9 g