CHEM 103 Chemistry (CHEM103)

The unit “m” stands for _______ in this experiment. 2. (4 points) Why was warming data used for estimating the freezing/melting point of the cyclohexane? 3. (3 points) How much of the cyclohexane solvent was placed in the test? 1.) molarity 2.) It is considered reliable. It is a dependable predicator of the freezing/melting point of a substnace. it can determine the temperatures when the change occurs. 3.) 10 mL of cyclohexane 1. molality 2. Solids tend to supercool, which gives fa...

Portage Chemistry 103 Module 3 Exam Study - Latest Update 2024

Bonds within a molecule are called intra-molecular bonds. Non-polar (type) compounds are insoluble in water. intra-molecular Correct! Non-polar Correct! Question 2 10 / 10 pts Fill in the blanks: Pentane is insoluble in water because it is a/an nonpolar (type) compound. Ethyl alcohol has a boiling point of 76.4 C and n-propyl chloride has a lower boiling point of 46.3 C because the Hydrogen bonds holding ethyl alcohol together are stronger than the nonpolar bonds which hold n-propyl chl...

The sample was coated with carbon in the SEM experiment. Answer the following question. A 1.1000 gram hydrate sample chosen from Na2CO3∙10H2O, AlCl3∙6H2O, MgCl2∙6H2O and BaCl2∙2H2O was heated and found to lose 0.5841 gram of H2O. (1) Show the calculation of the % H2O in the unknown hydrate sample. (2) Show the calculation of the % H2O in each of the hydrate compounds and identify the unknown hydrate from the list. Atomic weights: H = 1.008, O = 16.00. MWs: Na2CO3∙10H2O = 286.15,...

A reaction which gives off heat is said to be exothermic . Answer 1: Answer 2: 2. A decomposition reaction has more products than reactants. exothermic Correct! decomposition Correct! Question 2 10 / 10 pts Answer 1: Fill in the blanks: The reaction of AgNO with Cu is a single displacement type reaction. During the reaction of AgNO with Cu a blue (color) solution and black/gray (color) solid are formed. 3 3 single displacement Correct! Answer 2: Answer 3: blue Correct! black/gr...

Why is glass so often used as a material for lab containers? 3. What is the metal device used to hold hot containers? 4. What is the weighing dish used for solids? 5. What device is used to smother small fires? 1.) beaker 2.) glass is strong combat things like acid and other kinds of harsh stuff. It is neutral with most lab chemicals. 3.) tongs. 4.) watch glass 5.) fire blanket . 1. beaker 2. Glass is so often used as a material for lab containers because it is unreactive with most l...

In the Boyle’s law experiment, how was the volume of gas at different pressures determined? 2. (2 points) According to Boyle’s law, as the volume of a gas decreases, the pressure _________. 3. (6 points) A sample of gas occupies a volume of 10.5 L when the pressure is 14.3 psi. Use Boyle’s Law to calculate the volume (L) when the pressure is decreased to 12.8psi. Show the calculation. Answer: 1. A syringe was used, and the volume was read from the graduation markings. 2. increase...

What does it mean that the heat of a reaction is an extensive property? 2. (3 points) Does the following reaction give off heat or absorb heat? Explain briefly. C D H = +263Kcal/mol 3. (4 points) In one experiment in the video, room temperature water was mixed with water at about 38 degrees. To what temperature (about) did the mixture of the two water samples come to after setting for a few minutes? Answer: 1. The heat depends on the amount of substance. If the amount of substance is d...

Show the calculation of the heat of reaction (ΔHrxn) for the reaction: 2 C2H6 (g) + 5 O2 (g) → 4 CO (g) + 6 H2O (l) by using the following thermochemical data: ΔHf 0 C2H6 (g) = -84.0 kJ/mole, ΔHf 0 CO (g) = -110.5 kJ/mole, ΔHf 0 H2O (l) = -285.8 kJ/mole Your Answer: 2 C2H6 (g) + 5 O2 (g) → 4 CO (g) + 6 H2O (l) ΔHrxn = ∑ n ΔHf 0 (products) - ∑ m ΔHf 0 (reactants) ΔHrxn = 4 ΔHf 0 (CO) + 6 ΔHf 0 (H2O) - 2 ΔHf 0 (C2H6 ) - 5 ΔHf 0 (O2) ΔHrxn = 4 (-110.5 kJ/mole...

Classify each of the following as an element, compound, solution or heterogeneous mixture and explain your answer. 1. Barium chloride 2. Blood 3. Boron Answer: 1. Barium chloride - is not on periodic table (not element) - has two element names = Compound 2. Blood - is not on periodic table (not element) - no element names (not compound) appears to be one substance = Solution 3. Boron - is on periodic table = Element 7. Classify each of the following as a chemical change or a physical...