Which reaction is single replacement?
(1) 2h2o2 --> 2h2o + o2
(2) 2h2 + o2 --> 2h2o
(3) h2so4 + mg --> h2 + mgso4
(4) hcl + koh --> kcl + h2o

Achemistry student weighs out of phosphoric acid , a triprotic acid, into a volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with solution. calculate the volume of solution the student will need to add to reach the final equivalence point. round your answer to significant digits.

How many molecules are found in 1.32 mol of nacl?

What happens when light is scattered?