It takes 12.45 milliliters of 0.50 M NAOH to back titrate a mixture containing 1.25 grams of baking soda, NaHCO3, and 10.00 milliliters of 1.2 M HCL solution . Calculate the moles of antacid activity per gram of baking soda.

Explanation:

First, we will calculate the number of moles of both HCl and NaOH as follows.

     No. of moles of HCl = Molarity × Volume

                                      =        (as 1 L = 1000 ml)

                                      = 0.012 mol

   No. of moles of NaOH =  Molarity × Volume

                                    =      (12.45 ml = 0.1245 L)

                                   = 0.006 mol

Therefore, the amount of HCl reacts with will be as follows.

                   (0.012 - 0.06) mol

                  = 0.006 mol

Reaction equation for this reaction is as follows.

Here, one mole of HCl reacts with one mole of and it forms one mole of . Hence, moles of is 0.006 mol.

So,      

Here also, i mole of gives one mole of  .

So, = 0.006 moles

Now, moles of present per gram will be calculated as follows.

      Moles of per gram =

                              = 0.0048 g/mol

Thus, we can conclude that the moles of antacid activity per gram of baking soda is 0.0048 g/mol.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.  

the correct answer would be b) volume versus temperature, because they are also directly proportional.