Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721mmHg? Express your answer nume...
Typically, when a person coughs, he or she first inhales about 2.50 L of air at 1.00atm and 25 degreesC. The epiglottis and the vocal cords then shut, trapping the air in the lungs, where it is warmed to 37 degrees C and compressed to a volume of about 1.70L by the action of t...
Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydrogen peroxide,H2O2, can be titrated against a solution of potassium permanganate, KMnO4. The following equation represents the reaction: 2KMnO4(aq)+H...
A volume of 50.0 mL of aqueous potassium hydroxide was titrated against a standard solution of sulfuric acid. What was the molarity of the KOH solution if 19.2 mL of 1.50 M H2SO4 was needed? The equation is 2KOH(aq) +H2SO4(aq)-» K2SO4(aq)+2H2O(l)
A duck has a mass of 2.3 kg. As the duck paddles, a force of 0.07 N acts on it in a direction due east. In addition, the current of the water exerts a force of 0.26 N in a direction of 48° south of east. When these forces begin to act, the velocity of the duck is 0.15 m/s ...
i have 3 pints oil and 12 gallons of gas,each lawn mower uses 0.5 pints of oil and 1.5 gallons of gas. How many days can she mow lawns?
Thank you! Now I am having problems with part e.
I put in the wrong numbers for the second part.
I can't figure out how to get the initial pH. Also, when I tried part B I used 21.0 mL*.100M=XmL*0.130 and it wasn't the correct answer.
Consider the titration of 21.0 mL sample of 0.110 M HC2H3O2 with 0.130 M NaOH. what is the initial pH? what is the volume of added base required to reach equivalance point? what is the pH at 5.00 mL of added base? pH at one half o the equivalence point? pH at the equivalence p...
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