The amount of material needed to make a solution can be determine by using the f

Question

The amount of material needed to make a solution can be determine by using the formula: g=(FW)(V)(M) where g is the total grams needs fw is the formula weight of the compound, V is the volume in liters, and M is the desired molar concentration. unless otherwise specified, it can be assumed that the salts to make your buffers are suspended in water. For cellular work mille-Q water is appropriate and is the grade that was used to make the buffers you are using today. Calculate the appropriate amount of each compound necessary to create the buffers you are working with. Buffer 1: 100mL 0.1M Tris-HCI, 10mM DTT, pH 9.4 (FW This-HCI: 157.59g/mol, DTT: 154.25g/mol) Buffer 2: 250mL1.2M Sorbitol, 20mM potassium phosphate, 0.5mM MgCl, pH7.4 (FW Sorbitol:182.17g/mol, Potassium phosphate:136.086g/mol, MgCI:95.211g/mol)

Explanation / Answer

In this question, you only need to use the formula above to calculate the grams. It already say in the problem that water is the solvent, so the total volume is the one reflected there. Use the same for both of the reactives and you'll be fine.

I'll do the first for you as example:

Buffer 1:

the volume is 100 mL (in liters is 0.1 L) and we have the molecular weight and concentration for both reactants so:

mass of Tris HCl = 0.1 L * 157.59 g/mol * 0.1 mol/L = 1.5759 g

mass of DTT = 0.1 L * 154.25 g/mol * 10 mmol/L * 1 mol/1000 mmol = 0.15425 g

Doing the same thing for buffer 2:

m sorbitol = 1.2 * 0.250 * 182.17 = 54.65 g

m MgCl = 95.211 * 0.250 * 0.5/1000 = 0.0119 g

m Potassium phosphate = 136.086 * 0.250 * 20/1000 = 0.6804 g

Hope this helps. If you think that you need more explanation or something to be fixed, tell me in a comment.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.