Question

Distilled water (4.839 ml) is added to a cuvette for calibration of the spectrovis. 3 aliquots, each 145.223 µl in volume, of 0.40 m cuso4 are then added sequentially to the water in the cuvette. what is [cuso4] after the third aliquot is added? provide your response to three digits after the decimal.

Answer 1

`[\text{CuSO}_4] = 0.033\; \text{mol}\cdot\text{L}^(-1)`

Step-by-step explanation:

`c = n / V`

`\left\begin{array}{ccc}1 \; \mu \text{L} &=& 1 \cdot 10^(-6) \; \text{L}\\1 \; \text{ml} &=& 1 \cdot 10^(-3) \; \text{L}\end{array}\right`

`\left\begin{array}{ccc}n(\text{CuSO}_4) & = &c(\text{CuSO}_4, \text{conc.}) \cdot V(\text{CuSO}_4, \text{conc.})\\&=&0.40 \; \text{mol} \cdot \text{L}^(-1) \cdot 3\cdot 145.223 \cdot 10^(-6)\; \text{L}\\&=&1.743 \cdot 10^(-4) \; \text{mol}\end{array}\right`

`\left\begin{array}{ccc}V(\text{CuSO}_4) &=& 4.839 \cdot 10^(-3) \; \text{L} + 3 \cdot 145.223 \cdot 10^(-6) \; \text{L}\\ & = & 5.275 \cdot 10^(-3)\; \text{L} \end{array}\right`

`[\text{CuSO}_4] = n/V = 0.033 \; \text{mol} \cdot \text{L}^(-1)`