The answer is (D) microscopic. You can remember this, because the name is very close to "microscope," an instrument used to greatly magnify and observe tiny organisms and objects.
Answer:
0.1472 mol/L is the concentration of the barium hydroxide solution.
Explanation:

Mass of potassium hydrogen phthalate = 2.050 g
Molar mass of potassium hydrogen phthalate = 
According to reaction , 2 moles of potassium hydrogen phthalate reacts with 1 mole of barium hydroxide, then 0.01004 moles of potassium hydrogen phthalate will :
of barium hydroxide
Moles of barium hydroxide = 0.005020 mol
Volume of the barium hydroxide solution = 34.10 mL = 0.03410 L
1 mL = 0.001 L

Molarity of the barium hydroxiude silution :

0.1472 mol/L is the concentration of the barium hydroxide solution.
A is the answer I know bc I take biology
We have that every gas satisfies the fundamental gas equation, PV=nRT where P is the Pressure, V is the volume of the gas, n are the moles of the gas, R is a universal constant and T is the Temperature in Kelvin. We have that PV/T=nR and during our process, the moles of the gas do not change (no argon enters or escapes our sample). See attached.
a scale-model mound made of the same materials that make the real hill