Question

For the Bradford assay, the instructor will make a Bradford reagent dye by mixing 50 ml of 95% v/v ethanol with 100 mg of Coomassie Blue followed by the addition of 100 ml of 85% v/v phosphoric acid. This entire mixture is then diluted to 1 liter with water. What is the final concentration of phosphoric acid?

Answer 1

Answer:

4.25% is the final concentration of phosphoric acid.

Explanation:

Initial concentration of phosphoric acid = $C_1=85\%=0.85$

Initial volume of phosphoric acid = $V_1=50 mL$

Final concentration of phosphoric acid = $C_2=?$

Final volume of phosphoric acid = $V_2=1 L=1000 mL$

( 1L = 1000 mL)

$C_1V_1=C_2V_2$

$C_2=\frac{C_1times V_1}{V_2}$

$=\frac{0.85\times 50 mL}{1000 mL}=0.0425=4.25%$

4.25% is the final concentration of phosphoric acid.