Question 558276: A freshman is currently enjoying the Arts Studio program she is pursing at a well-know university. In her free time, she like to skate, take salsa dance lessons, and cook. She particularly enjoys pickling and decides to pickle olives over a lesisurely weekend. Accordng to the recipe, she needs to add three teaspoons of salt to one cup of diced olives. However, she erroneously adds six teaspoons instead. Each teaspoon of salt weighs about 5g and contains about 2300mg of sodium.
a). include all steps required for calculation
b). use correct procedure for conversion
c). deterine the amount of sodium acctually added, in grams
d). state the chemical fourmul of salt
e). classified the bond as ionic, polar covalent or non-polar convalent.
Answer by KMST(5328)   (Show Source):
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b) The conversion factor to get from teaspoons to milligrams of sodium, as stated in the problem, is (2300 mg sodium/1 teaspoon salt)
We can multiply it times (1 g sodium/1000mg sodium) to get
(1 g sodium/1000mg sodium)(2300mg sodium/1 teaspoon salt)=2.3 g sodium/1 teaspoon of salt
c) Based on that conversion factor, the 6 teaspoons of salt added contributed
(6 teaspoons salt)(2.3 g sodium/1 teaspoon of salt)=13.8 g sodium
d) Table salt is sodium chloride, with formula NaCl.
e) The sodium and the chlorine are present as ions Na+, and Cl- (The + and - are supposed to be superscripts, written higher than the other characters, as if they were exponents). The sodium cations and chloride anions are charged and held together by electrostatic forces (opposites attract). It is called an ionic bond.
It is not really a molecule. A salt crystal is an arrangement of sodium ions and chloride ions, with same number of both, but not arranged in pairs. Each sodium ions is surrounded by chloride ions, and each chloride ion is surrounded by sodium ions. The minimum unit with the composition of sodium chloride would be one ion of each. That is called a formula unit (not a molecule). The mass of a formula unit of sodium chloride, in atomic mass units, is the sum of the atomic masses of sodium and chlorine (22.99+35.45=58.44) and is the formula weight of sodium chloride. It is a formula weight, not a molecular weight. The ratio of masses of sodium and sodium chloride is (22.99 units of Na/58.44 units NaCl).
From that ratio we can calculate
(22.99 g Na/58.44 g NaCl)(about 5 g NaCl/1 teaspoon salt)=about 2 g Na/1 teaspoon salt
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