Drawing lewis structures satisfying octet rule

Question

Assignment:

Q1. A sample of unknown Y is subjected to elemental analysis. The following percentages by weight are found to be:

C 40.0% H 6.7% O remainder of % by weight

The molar mass is found to be 60.0 g

A. Calculate the empirical formula (show work)

B. What is the molecular formula of unknown Y. (Include reasoning)

Q2. For the following compounds, draw the Lewis structures satisfying the octet rule. Show all the bonds and include any non-bonding pairs. Multiple bonds may be necessary in your final structures.

C₃H₈O C₂H₃CL

Q3. Refer to the following chemical equilibrium to answer the questions below:

CH₃NH₂ + HCOOH<-> HCOO^- + CH₃NH₃⁺
pKa = 3.75 pKa = 10.56
(in water@25degrees C) (in water@25degrees C)

a. What is the K_a of HCOOH?
b. What is the base on the left side of the equilibrium?
c. What is the conjugate base on the right side of the equilibrium?
d. Which side of the equilibrium is favored?
e. What is the pK_b of HCOOH?

Provide complete and step by step solution for the question and show calculations and use formulas.