Question

You are about to perform some intricate electrical studies on single skeletal muscle fibers from a gastronemius muscle. but first, you must prepare 6l of a 170 mm nacl solution in which to bath the isolated muscle during your studies. how many grams of nacl must you weigh out on the lab balance to prepare this bath solution? (hint: the molecular weight of nacl is 58.44 grams/mole).

Answer 1

To prepare a 6L solution of 170 mM NaCl, you need to calculate the moles required and use the molecular weight of NaCl to convert to grams. Multiply the molarity by the volume to get moles, and then multiply by the molecular weight to get 59.6088 grams.

Step-by-step explanation:

To prepare a 170 mM NaCl solution, you will need to calculate the number of grams of NaCl required. First, you need to understand the concentration units. Here, 170 mM (millimolar) indicates 170 millimoles of NaCl are needed per liter of solution. To find out how many millimoles you need for 6 liters, you multiply 170 mmol/L by 6 L, yielding 1020 mmol, or 1.020 mol since 1000 mmol is equivalent to 1 mol.

Next, you use the molecular weight of NaCl, which is 58.44 g/mol, to convert moles to grams. The calculation is:

• 1.020 mol × 58.44 g/mol = 59.6088 g

Therefore, you would need to weigh out 59.6088 grams of NaCl and dissolve it in enough water to make the total volume up to 6 liters.

Answer 2

I'm quite confused with the given unit for concentration reported as 'mm'. Usually that would just be 'm' for molality or 'M' for molarity. Based on the given data, I think that would be mM which is 1/1000 of M. So, 170 mM is equal to 0.17 M. With that being said, the solution is as follows:

0.17 M = Moles solute/ 6 L
Moles solute = 1.02 moles
Mass of solute = 1.02 moles * 58.44 g/mole = 59.6088 grams NaCl