Laboratory Activity: Teacher Notes

(13.5 mL - 0.2 mL)/(10 mL filtrate) x (0.825 mg NaCl)/(1 mL AgNO₃) =

(11.0 mg NaCl)/(10 mL filtrate)

(11.0 mg NaCl)/(10 mL filtrate) x (300.0 mL filtrate)/(10.0 g pretzels) =

(33.0 mg NaCl)/(1 g pretzels)

(33.0 mg NaCl)/(1 g pretzels) x (28.4 g pretzels) = 937 mg NaCl

(937 mg NaCl) x (23.0 mg Na)/(58.5 mg NaCl) = 368 mg Na

2. The following information was given on a snack label:
   • Package Weight: 10 oz (283 g)
   • Serving Size: 1/2 oz
   • Sodium per Serving: 90 mg
   1. Calculate the mg NaCl per serving.

      (90 mg Na)/serving x (58 mg NaCl)/(23 mg Na) = (227 mg Na)/serving

   2. Calculate the grams of NaCl and teaspoons of NaCl in the entire package (1 teaspoon NaCl = 6 g).

      (0.227 g NaCl)/(0.50 oz) x (10 oz)/package = (4.54 g NaCl)/package

      (4.54 g NaCl)/package x (1 tsp NaCl)/(6.0 g NaCl) = 0.76 tsp NaCl

3. Obtain information from labels on products in the grocery store concerning the sodium content of the following: cookies, hot cereals, soda crackers, canned vegetables, dry cereals, canned fruit, popcorn, cheese-flavored snacks.

   Which of these foods would be recommended for a low-sodium diet? Compare the salt content of normal prepared spaghetti sauce with the low sodium variety.

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