This is MCQ # 830 of 1000 Pharmacy MCQs

Pharmaceutical Calculation Problem solution

830. How many grams of sodium chloride are there in 30 millimoles of NaCl, given the molecular weight of NaCl as 58.5?
a- 58.5
b- 30
c- 15
d- 2
e- 1.755


Solution:

To convert from millimoles to moles, we need to divide by 1000:

30 millimoles NaCl = 30/1000 moles NaCl = 0.03 moles NaCl

The mass of one mole of NaCl is 58.5 grams, so the mass of 0.03 moles of NaCl is:

0.03 moles NaCl × 58.5 grams/mole = 1.755 grams NaCl

Therefore, there are 1.755 grams of NaCl in 30 millimoles of NaCl.

Thus the correct answer is e.