Question

Many individuals increase their Ca2+ intake by taking calcium supplement tablets containing CaCO3. A bottle of 60 tablets costs $3.98 and contains 3.175 ounces of calcium supplement tablets. Each tablet has a total mass of 1.500 grams and contains 600.0 mg of Ca2+.

a.) Using the unit cost, calculate the cost per ounce of the calcium supplement. I got this part, ($3.98/3.175 oz=$1.25 per ounce)

b.) Calculate the mass percent of Ca2+ present in one tablet.

c. ) Calculate the cost per ounce of Ca2+ ion in the calcium supplement.

d.) How many tablets would you need to take to reach a 1200 mg daily allowance of Ca2+?

e.) If a cup of dried milk powder has a mass percent of 1.23% Ca2+, how many cups of milk would you need to drink to reach a 1200 mg daily allowance?

Answer 1

(a) Answer to part (a) is correct.

(b) mass % of Ca²⁺ = (Mass of Ca2+ / Mass of the tablet ) X 100

mass % of Ca²⁺ = (0.6g / 1.5 ) X 100 = 40%

600mg = 0.6g

(c) mass of Ca²⁺ in one tablet = 0.6g = 0.021 ounce

mass of Ca²⁺ present in 60 tablets = 0.021 X 60 = 1.26 ounce

cost of 60 tablets (or 1.26 ounce of Ca²⁺ ) = 3.98$

cost of 1 ounce of Ca2+ = 3.98$ / 1.26 = 3.158$

(d) Each tablet contains 600mg of Ca2+, hence we need to take 2 tablets to reach 1200mg of Ca2+.

(e) 1 cup = 240 grams

mass of Ca2+ in 1 cup (or 240 g) = 240 X 1.23 / 100 = 2.952g

2.952g of Ca2+ are present in in 1 cup

1g will be present in 1 / 2.952 = 0.339 cups

Hence 1.2g (or 1200mg) will be present in 1.2 X 0.339 = 0.407 cups

Hence we must take 0.407 cups of dry milk powder.