Phenolphthalein is often used as an indicator in acid–base titrations. For this application, it turns colorless in acidic solutions and pink in basic solutions. Phenolphthalein is slightly soluble in water and usually is dissolved in alcohols for use in experiments.
Answer:
194.6 mL of SO₂
Explanation:
The reaction that takes place is:
P₄S₃ + 6O₂(g) → P₄O₁₀ + 3SO₂(g)
<u>To solve this problem we need to use PV=nRT</u>, so first let's convert the given units:
- 23.8 °C → 23.8 + 273.15 = 296.95 K
- 747 torr → 747/760 = 0.983 atm
We need to calculate V, so in order to do that we calculate n, using the mass of the reactant (P₄S₃):
0.576 g P₄S₃ * 
= 7.85 * 10⁻³ mol SO₂ = n
PV=nRT
0.983 atm * V = 7.85 * 10⁻³ mol * 0.082 atm·L·mol⁻¹·K⁻¹ * 296.95 K
V = 0.1946 L
- Finally we convert L into mL:
0.1946 * 1000 = 194.6 mL
The solution changed color because the substances are not neutral.
<h3>
pH</h3>
Chemical substances have different concentrations of the hydrogen cation, called PH.
The higher the pH, the more basic the substance, and the lower the more acidic.
Bromothymol blue is a pH indicator that changes its color according to the pH of the substance, yellow for acid, blue for basic and green for neutral.
In the case of the reactions in question, we have the release of CO2 (acid) in combustion and in cellular respiration, changing the color of bromothymol blue to yellow.
Learn more about pH in: brainly.com/question/491373
