Consider the following indicators and their pH ranges: Methyl orange 3.2-4.4
Methyl red 4.8-6.0
Bromothymol blue 6.0-7.6
Phenolphthalein 8.2-10.0
Alizarin yellow 10.1-12.0
Assume an indicator works best when the equivalence point of a titration comes in the middle of the indicator range. For which of the following titrations would methyl red be the best indicator?
a) 0.100M HNO3+0.100M KOH.
b) 0.100M aniline(Kb=3.8×10^-10)+0.100M HCl.
c) 0.100M NH3(Kb=1.8×10^-5)+0.100M HCl.
d) 0.100M HF(Ka=7.2×10^-4)+0.100M NaOH.
e) 0.100M acetic acid(Ka=1.8×10^-5)+0.100M NaOH.

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.