Please show how to do each step

LAB: Mass Percent

1-Weigh approximately 5 g NaCl on weigh paper and add to a 250 ml Erlenmeyer flask. Record the exact mass here (The mass is 4.85 g )

2-Using a 100 ml graduated cylinder, add 100 ml water to the flask and stir until the solute has dissolved. Calculate the concentration in mass percent of this solution assuming the density of the water is 1 g/ml.

Solution + flask =227.747 g

Flask =81.565 g

3-Transfer 60.0 ml of the NaCl solution using a 100 ml graduated cylinder to a PREVIOUSLY weighed 150 ml beaker. The mass percent of the solution in the beaker is _______________.

The beaker mass is 93.469 g

4-Weigh the beaker with the 60 ml solution sample and record the mass here _153.623 g. Calculate the mass of solution as well as the mass of solute in the beaker.

5-Transfer 40.0 ml of the NaCl solution from the Erlenmeyer flask to a PREVIOUSLY weighed 150 ml beaker. Don’t forget to weigh the beaker before adding the NaCl solution to it. Record the mass of the beaker is 93.495 g. The mass percent of this solution in the beaker is _______________.

6-Weigh the beaker with the solution and record the mass here 133.790 g. Calculate the mass of solution as well as the mass of solute in the beaker.

7-Compare the masses of the solutions and solutes in each beaker (calculated values in numbers 4 and 6) with their respective concentrations.

Using values from Appendix C of your textbook, calculate the value of Ho, So, and Go for each of the following reactions at standard temperature (298 K). Next calculate G if ALL of the GASSES in the reaction have partial pressures of 0.2 atm.

(a) NaOH(s) + CO2(g) NaHCO3(s) Ho = -127.44 kJ/mol

So = -176.02 J/mol-K

Go = -74.96 kJ/mol

If all gasses have partial pressures of 0.2 atm then G = ________ kJ/mol.

(b) 2 Fe(s) + 3 CO2(g) Fe2O3(s) + 3 CO(g)

Ho = ______kJ/mol

So = _______ J/mol-K

Go = ___________kJ/mol

If all gasses have partial pressures of 0.2 atm then G = ___________kJ/mol.

(c) 2 C2H6(g) + O2(g) 2 C2H4(g) + 2 H2O(g)

Ho = ___________ kJ/mol

So = ________ J/mol-K

Go = ___________ kJ/mol

If all gasses have partial pressures of 0.2 atm then G = _________ kJ/mol.

(d) 6 C(graphite) + 6 H2O(l) C6H12O6(s)

Ho = _______ kJ/mol

So =________ J/mol-K

Go =_________ kJ/mol

If all gasses have partial pressures of 0.2 atm then G = __________ kJ/mol.

Why is it better to use a rotovap instead of a hot plate to evaporate ether?

Consider the following data on some weak acids and weak bases:

Use this data to rank the following solutions in order of increasing pH. In other words, select a '1'next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.

Solution pH

0.1 M NaCl

0.1 M C6H5NH3Cl

0.1 M C5H5NHBr

0.1 M NaCN

The laboratory reports that the concentration of ammonia as nitrogen in a sample is 3.4 mg/l. The pH value of the sample is 5.5 units. In what form is almost all of this ammonia? could this sample be toxic to aquatic organisms?

Assume you dissolve 0.235 g of the weak acid benzoic acid, C₆H₅CO₂H, in enough water to make 9.00 ✕ 10² mL of solution and then titrate the solution with 0.153 M NaOH.

C₆H₅CO₂H(aq) + OH^-(aq) C₆H₅CO₂^-(aq) + H₂O(ℓ)

What are the concentrations of the following ions at the equivalence point?

Na⁺, H₃O⁺, OH^-

C₆H₅CO₂^-

M Na⁺

M H₃O⁺

M OH^-

M C₆H₅CO₂^-

What is the pH of the solution?

Select the reactions for which we should expect a delta S (entropy) to be >0. Can select more than one.

CO2 (g) + 2H2 (g)-->CH3OH (l)

2SO2 (g) + O2 (g)--> 2SO3 (g)

Ba(OH)2 (s)-->BaO (s)+ H2O (g)

FeCl2 (s) + H2(g)-->Fe (s)+2HCl (g)

Suppose we have a solution of lead nitrate, Pb(NO3)2(aq). A solution of NaCl(aq) is added slowly until no further precipitation occurs. The precipitate is collected by filtration, dried, and weighed. A total of 11.72 g of PbCl2(s) is obtained from 200.0 mL of the original solution. Calculate the molarity of the Pb(NO3)2(aq) solution.

You have a one liter solution of kerosene containing 25 wt% propionic acid, add one liter of water, mix thoroughly and allow the two phases to settle. At this temperature, the distribution coefficient for propionic acid is 0.175 mass fraction in kerosene/mass fraction in water. What is the expected composition (wt%) and mass (kg) of the two phases? You may need to acquire physical properties for some of your species.

A solution is made by dissolving 40.0 g of KOH in 100 mL of water (density 0.995 g/mL) to form a solution. What is the mass percent solute in the solution?

1. 40.2%

2. 40.0%

3. 3.49%

4. 28.6%

5. 28.7%

25.0 g of water cooled 10 C to -20 C. Calculate the total Energy change.

With these useful numbers: ΔH fus = 334 J/g Δvap = 2260 J/g C_p for ice = 2.08 J/g ⁰C C_p for liquid water = 4.18 J/g ⁰C C_p for steam = 1.8 J/g ⁰C

Order: Vancomycin 12 mg/kg IV every 8 hours for an 11 year old child with a staph infection.

Supply: Vancomycin 500 mg vial to be reconstituted with 10 mL of sterile water. The child weighs 77 lb.

How many ml will you draw from the vial after reconstitution? _____________________

Order: Duricef oral solution 30 mg/kg PO bid for a 7 year old child with tonsillitis. The bottle of medication is labeled 250 mg per 5 mL. The child weighs 44 lb.

How many mL will you give? __________________

Order: Fragmin 80 units/kg SQ every 12 hours for unstable angina. The available dose is 10,000 units per mL.

The patient weighs 140 lb

How many mL will you give? _____________________

At 55.0 ?C, what is the vapor pressure of a solution prepared by dissolving 70.6g of LiF in 265g of water? The vapor pressure of water at 55.0 ?C is 118 mmHg. Assume complete dissociation of the solute.

The solvent for an organic reaction is prepared by mixing 60.0mL of acetone (C3H6O) with 59.0mLof ethyl acetate (C4H8O2). This mixture is stored at 25.0 ?C. The vapor pressure and the densities for the two pure components at 25.0 ?C are given in the following table. What is the vapor pressure of the stored mixture?

Write the complete electron configurations Cobal(Co) atom for its:

        1-its ground state
         2- an excited state       
2- Draw the orbital diagram for the complete electron configuration of Sulfur atom

3-Briefly explain how the following concepts are used in developing electron configuration of atoms: Hund’s rule and Pauli Exclusion principle.

2. Write the balanced chemical equation including states of matter, complete ionic reaction and net ionic reaction for the reaction between barium nitrate, Ba(NO3)2, and sodium chromate, Na2CrO4.
a. Balanced Chemical Equation
b. Complete Ionic Reaction
c. Spectator Ions
d. Net Ionic Reaction
3. Write a complete ionic reaction and a net ionic reaction for the following balanced chemical equation.
NaOH (aq) + C6H5COOH (aq)  H2O (l) + C6H5COONa (aq)       
4. Consult an internet resource for photographs of copper(I) oxide and of copper(II) oxide. Can one visually distinguish between these two compounds? Explain.   
Chemical Reactions and Equations p.14
5. Answer the following questions about the reaction:
S2-   +   NO3-    SO42-   +   NO  
a. Element oxidized    ___________
b. Element reduced    ___________
c. Reducing reactant    ___________
d. Oxidizing reactant    ___________