Which one of the following is a combustion reaction? a. ch4 + 2 o2 co2 + 2 h2o b. hbr + naoh nabr + h2o c. xe (aq) + h2o(l) hxe(aq) + oh- (aq) d. nacl (aq) + agno3 (aq) nano3 (aq) + agcl (s)

What happens to the concentration of hydronium ions as the ph of a solution increases? a. hydronium ion concentration stays the same b. hydronium ion concentration decreases c. hydronium ion concentration increases