Tutor profile: Carl D.

I'm going to give a short introduction of myself.

Hallo! Ich heiße Carl. Ich bin einsundzweisig Jahre alt. Ich komme aus Princeton, WV. Ich studiere Pre-Pharmacy an der West Virginia University. Ich lerne Deutsch auch. Ich esse pizza und kochen gern. Meine Favorit Farbe ist blau.

Consider the titration of 80.0 mL of 0.100 M Ba(OH)2 by 0.400 M HCl. What is the pH of the solution after 30 mL of HCl.

The first thing you would do for this problem is detirmine what type of titration this is, and in this case it is Strong Base-Strong Acid, so we have complete dissociation in solution. The problem then turns into Limiting Reagent (which one runs out first). We multiply molarity by volume (in Liters) to get moles of each of our H+ and OH-. In this case, we get 0.016 moles of OH- (since our base has two stoichiometric moles of OH-) and 0.012 moles of H+. So, we have more moles of OH- in solution, thus meaning we subtract moles of H+ from OH-, giving us 0.004 moles of OH-. Next, we find the concentration of of OH- by dividing our moles (0.004) and our new volume of solution (80 mL + 30mL = 110mL OR 0.110 L), giving us 0.036M of OH-. Now that we know the concentration of OH-, we find the pOH by taking the -log of the OH- concentration, giving us 1.44. Since pH + pOH =14, we subtract 14 by our pOH value (1.44) giving us 12.56, the pH of the solution after titration.

1) Twenty-five percent of all household burglaries can be attributed to unlocked windows or doors. Crime is the result of opportunity plus desire. To prevent crime, it is each individual's responsibility to: A. provide the desire B. provide the opportunity C. prevent the desire D. prevent the opportunity 2)How many 36-passenger buses will it take to carry 144 people? A. 3 B. 4 C. 5 D. 6

1) The answer to the question is D. To prevent crime, an individual would not provide desire or opportunity, and neither would they prevent desire (because that's virtually impossible to do), but instead they would prevent the opportunity for criminals to attempt crimes. 2) For this question, all you need to do is divide 144 by 36 (which gives you 4). For a question like this, which gives you a pre-defined space for objects (in this case buses) you would divide the objects of the problem (in this case people) by the spaces available, and that would give you containers needed. Luckily, this question gave us an even 4. However if there were rollover (such a 4.2) you would round up to the nearest whole number.