How many mEq of Ca^+are available in a 500-mg tablet of calcium lactate pentahydrate ( molecular

How many mEq of Ca^+are available in a 500-mg tablet of...

Key Concepts

Stoichiometric Conversions

Stoichiometric conversions involve the use of balanced chemical relationships and conversion factors such as molecular weight and equivalent weight to translate between different measurement units (for example, mg to moles, or moles to equivalents). This process is fundamental in calculating the amount of a specific ion available from a compound in a given mass.

Milliequivalents

Milliequivalents (mEq) are a unit that quantifies the chemical activity of ions in a solution, taking into account both the molar concentration and the valence of the ion. They are used particularly in medical and nutritional contexts to standardize doses of electrolytes and minerals, ensuring accurate comparisons regardless of differences in ionic charges.

Valence and Equivalent Weight

Valence refers to the combining capacity of an ion or molecule, often related to the number of electrons an atom can donate, accept, or share. In the context of ion calculations, the equivalence concept uses the valence to determine the equivalent weight—the mass of the substance that supplies or reacts with one mole of electrons or hydrogen ions. This is crucial in determining the effective concentration of an ion in a solution.

Molecular Weight

Molecular weight (or molar mass) is the mass of one mole of a substance, expressed in grams per mole. It serves as a conversion factor in stoichiometry, allowing you to convert between the mass of a compound and the number of moles present, which is essential for quantitative chemical calculations.

Transcript

00:01 The purpose of this problem is we want to find the calcium content in a calcium tablet.

00:10 We dissolve it in use titration to find the content of calcium.

00:22 So here is the information we have.

00:33 So c -a -c -o -3 tablet is 1 .245 -0 gram.

00:54 We don't really need that number because we just want to find the milligram of calcium 2 plus in the tablet, and we don't need the percent.

01:10 How do we find it out? so as we're doing titration, so we dissolve calcium carbonate with hydrochloric acid.

01:25 So here is the equation, the balance chemical equation, and carbon dioxide.

01:53 So the hydrochloric acid we use is 50 millilitre and molarity is 0 .5 0 .00 molar.

02:16 But we don't use all of them so there is some leftover.

02:24 So the excess of hydrochloric acids we're going to use sodium hydroxide to titrate it and then the reaction neutralization reaction is this equation and then we know we use 40 .20 milliliter and the concentration is 0 .218 .4 molar and so since we know the volume and the molarity of sodium hydroxide and we we should also know the amount of hydrogen chloride.

03:24 So hydrochloride acids.

03:29 So since it's one -to -one ratio, so what we have for sodium hydroxide, so it's also the amount for hydrochloric acids.

03:44 So this is the excess amount of hydrochloric acid.

03:48 It will subtract from the total amount, we will know how much hydrochloric acid is actually used.

04:00 So this is the total, this is the excess.

04:03 We subtract, we'll be able to know the amount of a hydrate core acid that is used to neutralize calcium carbonate...

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