Thiamine hydrochloride (C12H18ON4SCl2) is a water-soluble form of thiamine (vitamin B1; Ka = 3.37×10−7). How many grams of the hydrochloride must be dissolved in 10.00 mL of water to give a pH of 3.50?

4. absorption has the highest risk of overdose due to increased potency. a. rectal b. oral c. transdermal d. intranasal

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

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.