Does the chemical equation CaCO3 + 2HC2H3O2 → Ca(C2H3O2)2 + H2O + CO2 meet the Law of Conservation of Mass?

Acamcorder has a power rating of 17 watts. if the output voltage from its battery is 7 volts, what current does it use?units:

The reactions shown here can be combined to make the overall reaction c(s) + h2o(g) ⇌ co(g) + h2(g) by reversing some and/or dividing all the coefficients by a number. a. c(s) + o2(g) → co2(g) k=1.363×10^69 b. 2 h2(g) + o2(g) → 2 h2o(g) k=1.389×10^80 c. 2co(g) + o2 (g) → 2 co2(g) k=1.477×10^90

What human activity increases beach erosion?