Compound C (MW = 550) is provided at a concentration of 25g/100mL. 1mL is taken and compound D is to be added (MW = 1025, concentration = 75mM) to give a final ratio of compound C:D of 4:1 . What volume of compound D is to be added? ''DR BOB 222 IT IS A GRAMS RATIO''
I can't figure it either, When one specifies ratio, one should specify the basis (moles, or mass, or volume). I think they probably mean mass ratio here, but frankly, who knows. The writer of the question probably had something in mind..
yeas it is a mean mass ratio could you show me how to do it Bob Pursley
I repeatedly responded to this query and asked what kind of ratio. After 3-4 days I FINALLY received the answer of mole ratio. That's why I answered it as a moles ratio. If you will take the answer I gave in mole ratio and convert to grams, step by step, you will obtain the grams ratio.
To determine the volume of compound D to be added, we need to first convert the given concentrations of both compounds C and D into the same unit of measurement.
Given:
Concentration of compound C = 25 g/100 mL
Concentration of compound D = 75 mM
Molecular Weight of compound C (MW_C) = 550
Molecular Weight of compound D (MW_D) = 1025
Compound C:D ratio = 4:1
Step 1: Convert the concentration of compound C to the same unit as compound D.
Since compound C is provided in grams, we need to convert it to millimoles (mmol) to match the concentration unit of compound D (mM).
To convert grams to millimoles, we use the formula:
Moles = Mass / Molecular Weight
Concentration_C (in mmol/mL) = (25 g/100 mL) / MW_C
= (0.25 g/mL) / 550 g/mol
= 0.0004545 mol/mL
Step 2: Determine the concentration of compound D in the same unit (mmol/mL).
Since the concentration of compound D is already provided in millimoles (mM), there is no need for conversion.
Concentration_D = 75 mM
Step 3: Calculate the volume of compound D to be added.
Given that the desired ratio of compound C:D is 4:1, the ratio of their concentrations should also be 4:1 to achieve this.
Ratio_Concentration = Concentration_C / Concentration_D = 4/1
Ratio_Concentration = (0.0004545 mol/mL) / (75 mmol/mL)
Ratio_Concentration = 0.0004545
Let V_D be the volume of compound D to be added in mL.
0.0004545 = (V_D / 1 mL) / Concentration_D
V_D = 0.0004545 mL / 75 mmol/mL
V_D = 0.00000606 mL = 6.06 μL
Therefore, to achieve a compound C:D ratio of 4:1, we need to add 6.06 μL (microLiters) of compound D to 1 mL of compound C.