Question

1. What is the molecular mass of N2O?

2. Sodium reacts with oxygen to form

sodium oxide and has the following

balanced chemical equation: 4 Na + O2 --> 2 Na2O. How many mole(s) of oxygen gas (O2) are needed to react with 16.0 moles of Na? (Hint: consider your coefficient ratios. Write the knowns and unknowns, then develop a plan.)

3. Sodium reacts with oxygen to form sodium oxide and has the following balanced chemical equation: 4 Na + O2 --> 2 Na2O. When you have 30 g of Na how many moles of Na2O are produced? Show all your work.

4. You are asked to calculate the concentration of a NaHCO3 (in water) solution in several ways and are given the following information: 25 g NaHCO3, 500 mL solution. (a) Calculate the mass/volume percent concentration. (b) Calculate the molarity of the solution.

5. What volume (L) of a 1.5 M KCl solution can be prepared by diluting 0.2 L of a 5M KCl solution?