Chem HW

25. 17.
Draw the structural formula of the ff:
c. 3-methylhexane
d. 4-ethyl-2,2-dimethyloctane
e. methylcyclohexane

25.18
Draw the structural formula of the ff:
c. 2,5-dimethylnonane
d. 3-ethyl-4,4-dimethylheptane
e. 1-ethyl-4-methylcyclohexane

Courtesy of Regina :))

Chem HW

1. What is the relationship of deltaG with the spontaneity of the reaction?
2. What does each condition of delta G indicate:

• deltaG=0, 
• deltaG=<0,
• deltaG=>0

Chem HW

19.38
Calculate ΔSo values for the following reactions by using tabulated So values from Appendix C. In each case, explain the sign of So.
(a)N2H4(g) + H2(g) → 2NH3(g)
(b) Al(s) + 3Cl2 → 2AlCl3
(c) Mg(OH)2 + 2HCl (g) → MgCl2(s) +2H2O(l)
(d) 2CH4 → C2H6(g) + H2(g)

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Chem HW

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5.18(a) Write an equation that expresses the first law of thermodynamics. (b) In applying the first law, do we need to measure the internal energy of a system? Explain. (c) Under what conditions will the quantities q and w be negative numbers?

5.19 Calculate (delta)E, and determine whether the process is endothermic or exothermic for the following cases: (a) A system releases 113kJ of heat to the surroundings and does 39kJ of work on the surroundings. (b) q=1.62kJ and w=-874J; (c) The system absorbs 77.5kJ of heat while doing 63.5 kJ of work on the surroundings.

5.20 For the following processes, calculate the change in internal energy of the system, and determine whether the process is endothermic or exothermic: (a) A balloon is heated by adding 900J of heat. It expands, doing 422J of work on the atmosphere. (b) a 50-g sample of water is cooled from 30 degrees C to 15 degrees C, thereby losing approximately 3140J of heat. (c) A chemical reaction releases 8.65kJ of heat and does no work on the surroundings.

CHEM HW

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Chem Problem Set

13.30
a)What is the molality of a solution formed by dissolving 1.50 mol of KCL in 16.0 mol of H2O?

13.32
Ascorbic Acid(Vitamin C - C6H8O6) is a water-soluble vitamin. A solution containing 80.5g of ascorbic acid issolved in 210g of H2O and has a density of 1.22g/mL at 55`C.
Calculate:
a. mass percentage.
b. mole fraction
c.molality
d. molarity of ascorbic acid in the solution..

13.34
The density of toluene(C7H8) is 0.867g/mL, and the density of thiophene(C4H4S) is 1.065g/mL. A solution is made by dissolving 10.0g of thiophene in 250.0mL of toluene.
a. Calculate the mole fraction of thiophene.
b. Calculate the molality of thiophene.
c. Assuming that the values of the solute and solvent are additive, what is the molarity of thiophene in the solution?

13.36
Calculate the number of moles of solute present in each of the ff. sol'ns.
a. 245 mL of 1.59M HNO3(aq).
b. 50.0 mg of an aqueous solution that is 1.25m NaCl.
c. 75.0g of an aqueous solution that is 1.50% sucrose(C12H22O11) by mass.

Courtesy of Cs 2013 blog.

Chem HW

The only homework for the weekend:
Pre-lab for Experiment 25 (p.90)

Chem Probset

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Thank you :D

Chem Handout

Paki-spread nalang sa dormers.