Below are 3 possible Lewis Structures for NCO-. Lewis Structures for NCO- Click to Show Image Description Structure A shows a bracketed Lewis structure labeled “(A)” below the structure. Inside the brackets, nitrogen is on the left, carbon is in the center, and oxygen is on the right. Nitrogen is triple bonded to carbon, and carbon is single bonded to oxygen. Nitrogen has one lone pair shown to its left. Oxygen has three lone pairs shown, with one above, one to the right, and one below the oxygen. A minus sign appears outside the brackets near the upper right. Click to Show Image Description Structure B shows a bracketed Lewis structure labeled “(B)” below the structure. Inside the brackets, oxygen is on the left, carbon is in the center, and nitrogen is on the right. Oxygen is double bonded to carbon, and carbon is double bonded to nitrogen. Oxygen has two lone pairs shown, with one above and one below the oxygen. Nitrogen has two lone pairs shown, with one above and one below the nitrogen. A minus sign appears outside the brackets near the upper right. Click to Show Image Description Structure C shows a bracketed Lewis structure labeled “(C)” below the structure. Inside the brackets, oxygen is on the left, carbon is in the center, and nitrogen is on the right. Oxygen is triple bonded to carbon, and carbon is single bonded to nitrogen. Oxygen has one lone pair shown to its left. Nitrogen has three lone pairs shown, with one above, one to the right, and one below the nitrogen. A minus sign appears outside the brackets near the upper right. In the textbox below, please answer the two following questions: Which TWO Lewis Structures ARE NOT the best? and   Why are these TWO Lewis Structures NOT the best?

Below are several compounds.  Identify each as either being an ionic or molecular compound. Table for Question 1 Compound ionic or molecular? SF4 NH3 CHCl3 TiF4 Ba(NO3)2

Give the melting point of ammonia at 700 torr. Enter numbers only.  It is understood that your answer is in Celsius (oC).

Suppose a solution containing a molecular solute has a solute mole fraction of 0.250. at a temperature of 20 oC. Calculate the vapor pressure (in torr) of the solution if the normal vapor pressure of water at that temperature is 17.54 torr.

You have 4 molecules. Molecule A is ionic, Molecule B is polar and capable of hydrogen bonding, Molecule C is polar and Molecule D is nonpolar.  Which molecule would you expect to have the highest boiling point?

Name the phase change(s) that take place when ammonia is cooled from -60 oC to -110 oC at a pressure of 300 torr.  Select all that apply.

Hydrogen and carbon monoxide react to give formaldehyde under certain conditions. The proposed mechanism is: Step 1:      

Read the following statement carefully before proceeding. By entering your full name in the blank below, you are electronically signing and agreeing to the following:I, , confirm that by beginning this exam, I commit to completing it in its entirety using only my own knowledge. I understand and agree to all of the following terms: I will not seek or receive assistance from any person, including but not limited to classmates, tutors, or instructors, in answering any question on this exam. I will not use any generative artificial intelligence (AI) tools, including but not limited to Claude, ChatGPT, DeepSeek, Grok, Meta AI, Google Gemini, or any similar technology, to assist in formulating or verifying my answers. I will not use search engines, websites, online resources, or any internet-based tools to locate answers. I will not consult textbooks, course notes, lecture materials, or any other printed or digital course resources. I understand this exam is entirely closed book and closed note. By signing above, I further attest that I have read, understand, and will uphold the Academic Integrity and Artificial Intelligence policies of this course and Penn State University. I understand that if an academic integrity violation is suspected, it will be subject to formal investigation. If I am found to be in violation, I may face appropriate sanctions, up to and including a failing grade (F) in this course.

Hydrogen and carbon monoxide react to give formaldehyde under certain conditions. The proposed mechanism is: Step 1:      

Read the following statement carefully before proceeding. By entering your full name in the blank below, you are electronically signing and agreeing to the following:I, , confirm that by beginning this exam, I commit to completing it in its entirety using only my own knowledge. I understand and agree to all of the following terms: I will not seek or receive assistance from any person, including but not limited to classmates, tutors, or instructors, in answering any question on this exam. I will not use any generative artificial intelligence (AI) tools, including but not limited to Claude, ChatGPT, DeepSeek, Grok, Meta AI, Google Gemini, or any similar technology, to assist in formulating or verifying my answers. I will not use search engines, websites, online resources, or any internet-based tools to locate answers. I will not consult textbooks, course notes, lecture materials, or any other printed or digital course resources. I understand this exam is entirely closed book and closed note. By signing above, I further attest that I have read, understand, and will uphold the Academic Integrity and Artificial Intelligence policies of this course and Penn State University. I understand that if an academic integrity violation is suspected, it will be subject to formal investigation. If I am found to be in violation, I may face appropriate sanctions, up to and including a failing grade (F) in this course.