Convert 15 grams of salicylic acid to moles

There are main groups in the modern periodic table of elements

How many liters of hydrogen gas will be produced at stp from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phosphoric acid (h3po4) the equation is 3mg + 2h3(> mg(po4)2+3h2

Which type of substance ionizes partially and gives off hydrogen ions when dissolved in water? a. strong acid b. strong base c. weak acid d. weak base