Chemistry Answers

. During a serial dilution, you use 15.0 mL of a standard solution and dilute it to 1.35 L twice. What is the final concentration if the standard solution had a concentration of 0.500 M? 

Find the concentration of all ions present in a 0.223 M solution of PbCl2. (2 marks for solvation, 2 marks for each concentration). 

A student adds 1.15 L of water to 750 mL of a 0.330 M solution of NaCl. What is the concentration of the diluted solution? 

what is the source and use of 2-methyl-3-hexene?

Determine the empirical formula if a compound is made up of 14.0 g Nitrogen and 8.00 g Oxygen. 

Using the average atomic masses for each of the following elements, calculate the mass (in amu) of each of the following samples.

1. 128 carbon atoms
2. Mass = amu
3.  potassium atoms
4. Mass = amu
5.  of lithium atoms
6. Mass =  amu

Merchants usually sell small nuts, washers, and bolts by weight (like jelly beans!) rather than by individually counting the items. Suppose a particular type of washer weighs 0.120 g on the average.

1. What would 62 such washers weigh?
2. g
3. How many washers would there be in 105 g of washers?
4. washers

Calculate the 1) average speed, 2) root mean square speed and, 3) most probable speed of oxygen molecules at 515k. (Given Mm(O2)=0.016kgmol^-1).

Calculate the pH of 0.01 M aqueous solution of sodium formate at 298 K. [Given:

Ka

(HCOOH) =1.7 × 10−4 at 298K]

1. Predict the products of the reaction of acetophenone with the following reagents

• 2 CH3OH, HCl catalyst
• Dess-Martin reagent