CHEM115 LAB 4 HYDRATED CRYSTALS

7. Identify as true (T) or false (F): All chemical particles exist in a constant state of random motion. In exothermic reactions, bonds in chemical particles generally become weaker. Matter can change its physical state with pressure alone, at a constant temperature. Dispersion forces work on only some chemical particles.

Can you please help me answer this

Identifying hydrogen-bonding interactions between molecules.

General Chemistry 4th Edition McQuarrie • Rock • Gallogly Consider the data in the table. Compound HF University Science Books presented by Macmillan Learning Melting point (°C) AHfus (kJ/mol) Boiling point (°C) AHvap (kJ/mol) -83.11 4.577 19.54 25.18 HCl -114.3 1.991 -84.9 17.53 HBr -86.96 2.406 -67.0 19.27 HI -50.91 2.871 Using the data in the table, calculate ASfus and ASvap for HCl. ASfus = ASvap = -35.38 21.16 Determine the entropy change when 6.10 mol HCl(g) condenses at atmospheric pressure. AS = J/(K. mol) J/(K⚫ mol) J/K

• Density: In both solids and liquids, the molecules are held very closely together and therefore their densities are about the same. In gases, there is space between the molecules. • Molecular movement and order: The molecules in solids are arranged in a regular pattern that does not allow for diffusion, although does allow for vibrations. The arrangement of molecules in a liquid, although not completely random, is not completely fixed. Molecules in a gas are randomly arranged and move very quickly. Gases diffuse quickly in comparison to liquids. Compressibility and thermal expansion: Since the molecules in solids and liquids are already very close together, applying pressure does not greatly affect the volume. In contrast, the space between gas molecules allows for a great deal of compressibility. Although temperature changes will cause slight variations in the volume of a solid or liquid, those variations are negligible compared to the thermal expansion of a gas. Shape and…

Draw another microscopic sketch of a small section of stream with the charged comb nearby. In your sketch, draw at least 2 layers of at least 10 water molecules. Show the polarization orientation of each water molecule in the stream of water when the charged comb is nearby. What is the distinct feature of the orientation of each molecule’s polarity in this second situation?

11. Hydrogen chloride is a compound. a. Draw a diagram to show how the electrons are arranged in a molecule of hydrogen chloride. Show only the outer electrons. Show hydrogen electrons as (circles) Show chlorine electrons as (x) b. State the name of the type of bonding present in hydrogen chloride._ c. Hydrogen chloride dissolves in water to form an acidic solution (hydrochloric acid). Describe how you would use litmus paper to show that this solution is acidic. d. Which one of the following values is most likely to represent the pH of a dilute solution of hydrochloric acid? Circle the correct answer pH2 pH7 pH10 f. Name the salt formed in this reaction. pH14 e. Complete the following equation for the reaction of hydrochloric acid with magnesium. Mg(s) + HCl(aq) → MgCl₂(aq) + H₂(g)

In a post-lab question, a student was asked to explain heat curves. This is what they wrote:   "A heating curve shows how the temperature of a molecule changes as it is heated. First, it starts as a solid below its melting point. Then, as heat is put in, the bonds start to break at the phase change, and the molecule becomes a liquid. The temperature of the molecule cools slightly at this point. Then, the temperature rises again because the heat going in makes the molecules have greater potential energy (motion). At its boiling point, more bonds break and it turns into a gas. The phase changes are the flat regions of the heating curves because all the heat going in is used to break the bonds."   While they have a lot right, there are a number of mistakes. Highlight or copy-and-paste 2 errors, and explain what is wrong/how to fix the errors.

Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. chemical symbol, chemical formula or Lewis structure substance boiling point dh A NO (Choose one) 0 :0: H H C-C-– H (Choose one) 8 H. :0: H-C-N– H (Choose one) e N2 (Choose one) e D Check Explanation O 2022 McGraw ill LLC. All Rights Reserved. Terms of Use I Privacy Center / Accessibility MacBook Air %23 3 4. Y U I D

Part A has been answered correctly and should be used to answer Part B

Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. chemical symbol, substance chemical formula boiling point or Lewis structure Ar (Choose one) A В Cr (Choose one) v H H. H. H - C - C - ) - C H (Choose one) | H H H. H H - C -H D :N - O - H (Choose one) ♥ Н—С — Н ? :0 : :

Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. chemical symbol, chemical formula or Lewis structure substance boiling point A Cr (Choose one) H Н— С —Н :N-O –H (Choose one) v Н — С — Н H Ar (Choose one) v H H Н— С — С — О — С — Н (Choose one) v H H H

What type(s) of compounds can be recrystallized? Liquids Gases Solids Liquids and Solids Liquids, Solids and Gases

Your roommate, a history student, has stumbled across nitrogen trifluoride in their history textbook because it was used in the 1960s and 1970s as rocket fuel oxidizer. They remember learning about chemical reactions in Grade 11 and want to make nitrogen trifluoride using nitrogen gas and fluorine gas. Since you are a chemistry student, you have decided to help them remember how to construct the formula. Your other roommate, who is a mathematics student, wants to create a hypothetical situation so that the history student can better understand the concept. She writes down a mass for fluorine gas and nitrogen gas.  1. If she wrote that the mass of nitrogen gas as 114.6 g and the mass of fluorine gas as 354.8 g which is the limiting reagent in this case? 2. The mass of nitrogen trifluoride produced that she wrote is 469.4 g. What is the theoretical mass of nitrogen trifluoride produced calculated using the given masses? Is this higher or lower than the mass that she wrote?  3. If it is…

CH2=CH2(g) + H2(g) CH3CH3 (g) is an example of . 5. This reaction: action. re- 6. It involves the addition of oxygen to a compound, which changes the functional group that is present is known as 7. An important biological molecule that has an amine functional group on one end of the mole- cule and a carboxylic acid functional group on the other end is known as reaction.

Look at the structure of a soap molecule, and explain what happened when you added soap to your oily hands and put your hands under the water for the solubility lab. Why could you wash the oil off your hands with soap and water? You should use chemistry concepts including structure, polarity, and intermolecular forces to explain your answer. attached is the lewis structure of a basic soap molecule. There are covalent bonds between all carbons, hydrogens, and oxygens. However, there is an ionic bond between oxygen and sodium ions.

1. MgO(s)+2 HCl(aq)->MgCl2(aq)+H2O(l) H1= 2. Mg(s)+2HCl(aq)->MgCl2(aq)+H2(g) H2= 3. H2(g)+1/2 O2(g)->H2O(l) H3= 4. Mg(s)+1/2 O2(g)->MgO(s) H4= enthalpy for formation of water: 2H2(g)+O2 (g)-> 2H2O(l) H=-572kJ

Rank the elements or compounds in the table below in decreasing order of their boiling points. That is, choose 1 next to the substance with the highest boiling point, choose 2 next to the substance with the next highest boiling point, and so on. substance chemical symbol, chemical formula or Lewis structure boiling point do HIC-H || (Choose one) A HIC H B H₂ (Choose one) :0: || (Choose one) ✓ HIC H Co (Choose one) S ? C D X

Carbon dioxide (CO2) and methane (CH4) exists as gaseous substances at room temperature. But dry ice is solid while liquefied natural gas (LNG) is liquid. Discuss the bonding pattern among the molecules of dry ice and LNG. cite references used

Some vitamins are soluble in water and some are fat soluble. Fats have structures made up of long C-H chains. The structural formulas of 2 vitamins are shown here. One is water soluble and the other is fat soluble. Identify each, and explain your reasoning. OH H,C CH3 CH3 CH3 но CH3 LOH CH3 но но H3C CH3

A hydrated salt is one in which water molecules are suspended in the crystal lattice structure of the salt. Upon heating what happens to these water molecules? What change can be expected in the structure and appearance of the salt?

compound hydrogen-bonding force Between Between molecules of formula or Lewis molecules of the the compound and molecules of water? name structure compound? H H | Н — С | | yes yes N-chloromethylamine - no no H. yes yes hydrogen iodide HI no no :0: || н —с —с-о — н H yes yes acetic acid no no H O O