Student Number:

a b c d e f g h i

Note: Change any “0” value in your student number to a “7”.

If b ≥ 7, x = 9 If d ≥ 7, y = 5

If b ≥ 4, x = 8 If d ≥ 4, y = 4

If b ≥ 1, x = 7 x If d ≥ 1, y = 3 y

# Dilutions

- How much of a x.e % (w/v) stock solution is required to create 20.0 mL of a y.i % (w/v)

solution? **[3 marks]**

- What is the final concentration of a solution if x.e mL solvent is added to y.d mL of a b.c M

solution? **[4 marks]**

- How much solvent must be added to b.c mL of a 34.6 % (v/v) stock solution to create at c.d %

(v/v) solution? **[4 marks]**

# Serial Dilutions

- What is the initial concentration of a solution that has a final concentration of 0.dg % (w/v) that has been serially diluted 1/b, then 1/c, then finally 1/d? (3 SD)
**[5 marks]**

- You have an aliquot of cells with a concentration of f.hi x 10 cells/mL.

x

Prepare a serial dilution to create e.f mL with a concentration of c.de x 10^{y} cells/mL.

Include your plan to accurately create this serial dilution. Include all the volumes of solute,

solvent, and total solution. **[10 marks]**

# Standard Curve

You collect the following data from a Spectrophotometer. **[2 marks]**

Concentration (mg/mL) | % Transmittance | Absorbance |

0.0 | 100 | |

0.625 | 93.7 | |

1.25 | 87.6 | |

2.5 | 76.6 | |

5.0 | 57.8 | |

10.0 | 33.7 | |

20.0 | 11.2 | |

Unknown | cd.e |

𝐴𝐴 = 2 − log (%𝑇𝑇)

- Using graph paper, create a handwritten Standard Curve.
**[10 marks]**

Ensure it is properly labeled and professional in appearance.

Using the % Transmittance data for the Unknown to determine the concentration.

- Using Microsoft Excel, create a table of values and a Standard Curve digitally.
**[10 marks]**

Using the equation from the Line of Best Fit, determine the concentration of the Unknown.

Submit a professional looking Table and Standard Curve.

- Calculate the Percent Error for the Unknown, using the digital data as Accepted Value. (2 SD)

**[2 marks]**