Which equation describes a reduction? o
2+
Mg(s) —Mg*(aq) + 2e
201 + 2e - →201
O
Na(s) — Na+ (aq) + e-
Al(s)
—A3+ (aq) + 3e-
0

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume