Question

ADDITIONAL QUESTIONS AND PROBLEMS 1. Why should the test tubes be dry? 2. Consider the most acidic sample and the most basic sample for the four consumer products in Part B. Based on the pH paper test results: a) The most acidic sample was: , with a pH-_ and a [H.-M. b) The most basic sample was: With a pHand a [H]M c) The most acidic sample was What is the pH for the following solutions (Show all work.): a) A hydrochloric acid solution that is 3.8 x 10 M times more acidic than the most basic sample. 3. b) A sodium hydroxide solution that is 3.8 x 10 M 4. What is the [H'] concentration for a hydrochloric acid solution with a pH 3.8(Show all work.)? 5. What does "pH balanced" mean in some household products? 6. The buffer system in the experiment consisted of the HCO3l-CO2-pair. a) The weak acidin this buffer system. b) The weak basein this buffer system. Consider human blood: 7. a) Look-up and record the normal pH range of blood. to b) What is the main buffer system that regulates blood pH? Weak Acid Weak Base- c) Briefly, what do the terms acidosis and alkalosis mean with respect to blood pH? http://www.chemistry wustl.edu/-edudev/LabTutorials/Buffer/Buffer html

Answer 1

Q 1) - It is very important to use dry test tube for doing tests

because,

a) In many reactions water will interfere and gives falls result e.g. in reactions which use NaI (sodium iodide) water will break bonding between Na and I and will gives falls result

b) in determination of melting point of pure compound if water is present in test tube you cannot find exact melting point because of water