Consider the reaction between 50.0 mL of 0.100 M sodium hydroxide and 75.0 mL of
ID: 556952 • Letter: C
Question
Consider the reaction between 50.0 mL of 0.100 M sodium hydroxide and 75.0 mL of 0.200 M HCl at 25 celsius. Which of the following statements is correct?
a) After the reaction, the concentration of Na+ is greater than the concentration of H3O+.
b) The HCl is the limiting reactant.
c) After the reaction, the concentration of Na+ is equal to the concentration of Cl-.
d) After the reaction, the concentration of Cl- is still 0.200 M because Cl- is a spectator ion.
e) The final soution has a pH about 1.1.
Explanation / Answer
a)
mol of NAOH = MV = 0.1*50*10^-3 = 0.005
mol of HCl = MV = 0.2*75*10^-3 = 0.015
clearly, there is much mor eHCl than NaOH
NaOH is limiting reaction
Na+ < H+ due to NaOH < HCl
a is false
b)
fals,e HCl is in excess
c)
False, since NaOH < HCl
d)
false, since Volume increases
e)
true, since acidic pH, [H+] is present