Part 1: a sample of silver (ag) has a mass of 31.78 g. a. what is the molar mass of silver? b. how many moles of silver are in this particular 31.78 g sample? c. how many atoms of silver are in this same sample? show work! you!

 The   molar  mass of   silver = 107.87 g/mol  ( from periodic table)

 The   moles of  silver   is 0.2946  moles

calculation

moles =mass÷  molar   mass

    = 31.78 g  ÷ 107.87 =0.2946 moles

The  number of atoms  of silver  that are  in this sample is 1.773 x 10²³  atoms

  calculation

According  to Avogadro's  law   1  mole  =   6.02 x 10²³  atoms

                                                  0.2946   moles= ? atoms

by  cross  multiplication

= [ (0.2946  moles x 6.02 x 10²³ ) / 1 mole]  = 1.773 x 10²³ atoms

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2