Balanced chemical equation:
2 H2 + 1 O2 = 2 H2O
4 g H2 -------> 32 g O2 -----------> 36 g H2O
↓ ↓ ↓
14.0 g ---------> 2.0 g O2 ----------> mass H2O ?
32 * mass H2O = 2.0 * 36
32 * mass H2O = 72
mass of H2O = 72 / 32
mass of H2O = 2.25 g
hope this helps!.
Answer is: a) in the presence of a base.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄).
When solution turns phenolphthalein pink, it means it is basic (pH>7).
I can’t see the picture for some reason but if I were to guess, I would say Pangea.
