(b) 25. Which equation is incorrectly balanced?
(a) 2 KNO3 4, 2 KNO2 + O2
(b) H2O2 H2O + O2
(c) 2 Na2O2 + 2 H2O - » 4 NaOH + O2
electrical energy
(d) 2 H,
2 H2 + O2
H2SO4

What happens when light is scattered?

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)

Uranium can supply energy for the worlds electricity without admitting harmful greenhouse gases which of these statements best describes an outcome of uranium mining