A water sample contains 50 mg/L of Zn2 . How high must the pH be raised to precipitate all but 1 mg/L of the zinc

The answer would be

1.75 is the weight of one medium egg

Combustion is the act or process of burning. therefore, i believe the answer is  a: burning wood. 

According to arrhenius theory of acid and bases, an acid is a proton donor, while base donates hydroxyl ions. further, acid and base reacts to form salt and water.consider following example.hcl    +      h2o          →      cl-          +      h3o+here, hcl has donated a proton, hence it is an acid.now consider following reactionhcl      +      naoh            ↔      nacl      +        h2oin this reaction, hcl donates proton, hence it is acid. on other hand, naoh donates hydroxyl ion (i.e. hence it is a base.