3.30Box (a) represents 1.0 mL of a solution of particles at a given concentration. Which of the boxes (b)–(d) represents 1.0 mL of the solution that results after (a) has been diluted by doubling the volume of its solvent?

3.31Reaction of A (green spheres) with B (blue spheres) is shown schematically in the following diagram: Which equation best describes the stoichiometry of the reaction? (a) A 2  2 B A 2 B 2 (b) 10 A  5 B 2 5 A 2 B 2 (c) 2 A  B 2 A 2 B 2 (d) 5 A  5 B 2 5 A 2 B 2

3.32Cytosine, a constituent of deoxyribonucleic acid (DNA) can be represented by the molecular model at the top of the next column. If mol of cytosine is submitted to combustion analysis, how many moles of and how many moles of would be formed?

3.33If blue spheres represent nitrogen atoms and red spheres represent oxygen atoms, which box represents reactants and which represents products for the reaction 2 NO(g)  O 2 (g) 2 NO 2 (g)?

3.34Fluoxetine, marketed as an antidepressant under the name Prozac, can be represented by the following ball- and-stick molecular model. Write the molecular formula for fluoxetine, and calculate its molecular mass (red  O, gray  C. blue  N, yellow-green  F, ivory  H).

3.35Assume that the buret contains H  ions, the flask contains OH  ions, and you are carrying out a titration of the base with the acid. If the volumes in the buret and the flask are identical and the concentration of the acid in the buret is 1.00 M, what is the concentration of base in the flask?

3.36The following diagram represents the reaction of A 2 (red spheres) with B 2 (blue spheres): Write a balanced equation for the reaction, and identify the limiting reactant. How many moles of product can be made from 1.0 mol of A 2 and 1.0 mol of B 2 ? (a) (b)

3.37A hydrocarbon of unknown formula C x H y was submitted to combustion analysis with the following results. What is the empirical formula of the hydrocarbon?