Answer:
16.8%
Explanation:
31% NaOH molar mass 40 gm
69% H2O molar mass 18 gm
1000 gm would be
310 gm NaOH or 310/40 = 7.75 moles
690 gm of H2O or 690/18 = 38.333 moles
7.75 / (7.75 + 38.333) = .168 mole fraction
The molarity of a hydrochloric acid solution : 0.32 M
<h3>Further explanation </h3>
Titration is a procedure for determining the concentration of a solution by reacting with another solution which is known to be concentrated (usually a standard solution).
Titrations can be distinguished including acid-base titration, depositional titration, and redox titration. An acid-base titration is the principle of neutralization of acids and bases is used.
Acid-base titration formula
Ma. Va. na = Mb. Vb. nb
Ma, Mb = acid base concentration
Va, Vb = acid base volume
na, nb = acid base valence
1 ⇒HCl (valence=1, HCl ⇒H⁺+Cl⁻, one H⁺)
2⇒Ca(OH)₂(valence=2, Ca(OH)₂⇒Ca²⁺+2OH⁻, two OH⁻)
M₂=0.1 M
V₂=48 ml=0.048 L
V₁=30 ml=0.03 L

.5 mol of A will be left over since 1.5 mol of A will be used for every 3 mol of B due to the 2:1 ratio established by the formula.
The answer is A. Volcanoes and earthquakes often occur near place boundaries. Volcanoes are exit points for heat from the Earth's core. And Earthquakes are caused by the tectonic places colliding along another one. For example one tectonic plate would be slowly moving south, and another next to it could collide with the South-going plate while going North, and that is what causes Earthquakes.