Week 1 Hand-In, Chem 210L / Partner:
See the rubric below for more detailed information about grading.
1. (1 pt) Write the net ionic equation for the reaction of iron(III) nitrate and potassium thiocyanate assuming a 1:1 stoichiometry for the reactants.
{ insert fully labeled equation here}
2. (2 pts) Determine the concentration of product in one of the solutions you made in the lab in part II. Follow these guidelines in showing your calculations.
a. You must use Microsoft Equation editor to show the equations.
b. You must show the steps in each calculation and explain, where necessary, what a number or set of calculations is doing.
c. Units must be clear and correct.
{Insert calculation here}
3. (3 pts). Use the information from the solutions of known concentration to determine Beer’s Law from the solutions prepared in lab for part II.
a. (0.5 pt) What is the maximal wavelength (lmax) at which you read the absorbances of all of your solutions? (this will have units of nanometers, nm)
{type answer here}
b. (0.5 pt) What is the relationship between the color you observed on the screen at the peak wavelength and the color of your solution?
{type answer here}
c. (2 pts) For one of the solutions prepared for part II of lab, calculate the [el] value for Beer’s Law for this reaction.
a. You must use Microsoft Equation editor to show the equations.
b. You must show the steps in each calculation and explain, where necessary, what a number or set of calculations is doing.
i. Start with Beer’s law equation,
ii. Rearrange Beer’s law equation to solve for el
iii. Fill in your values of concentration of product and absorbance and solve for el
iv. Be sure to round to correct sig. fig’s and include clear and correct units.
{ insert your calculations and necessary explanations here}
Grading Rubric
Unsatisfactory / Borderline / Satisfactory / Excellent / ScoreQ 1 / No equation is given / Reaction was not reduced to net ionic equation
0.25 pts / Net ionic equation correct, but states and/or charges on reactants and products not given. / Net ionic equation and spectator ions are not included (0.5 pt)
States are given
Charges on reactant and products are correctly given (0.5 pt) / 1 pt
Q 2 / Not using Microsoft Equation or similar equation editor but stringing out calculations in lines of text and numbers.
0 points / Major mistakes in calculations or units or product incorrectly identified.
0.5-1 points / Minor calculation errors and/or incorrect rounding
1-1.5 points / Correct calculations of concentration of product
(1 pt)
Correct use of units and labeling and rounding to correct sig figs (1 pt).
2points / 2pts.
Q3 / Not using Microsoft Equation or similar equation editor but stringing out calculations in lines of text and numbers.
0 points / 0.5-1 points / 1-2 points / Maximal wavelength
(0.5 pts)
Explanation of relationship between maximal wavelength (light color) and color of solution (0.5 pts)
Correct calculations
(1 pt).
Correct use of units and labeling and rounding to correct sig figs and explanations of calculation steps (1 pt).
3points / 3 pts