Textbook Question
(a) By titration, 15.0 mL of 0.1008 M sodium hydroxide is needed to neutralize a 0.2053-g sample of a weak acid. What is the molar mass of the acid if it is monoprotic?
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Ch.4 - Reactions in Aqueous Solution
Chapter 4, Problem 108
A fertilizer railroad car carrying 129,840 L of commercial aqueous ammonia (30% ammonia by mass) tips over and spills. The density of the aqueous ammonia solution is 0.88 g/cm³. What mass of citric acid, C₆H₈O₇ (which contains three acidic protons), is required to neutralize the spill?
Verified step by step guidance1
Convert the volume of the aqueous ammonia solution from liters to cubic centimeters (cm³) using the conversion factor 1 L = 1000 cm³.
Calculate the mass of the aqueous ammonia solution using the formula: mass = volume × density. Use the density provided (0.88 g/cm³) and the volume in cm³.
Determine the mass of ammonia (NH₃) in the solution by using the percentage by mass (30%). Multiply the total mass of the solution by 0.30.
Write the balanced chemical equation for the neutralization reaction between ammonia (NH₃) and citric acid (C₆H₈O₇). Each mole of citric acid can neutralize three moles of ammonia.
Calculate the moles of ammonia using its molar mass (17.03 g/mol), then use the stoichiometry from the balanced equation to find the moles of citric acid needed. Finally, convert the moles of citric acid to mass using its molar mass (192.12 g/mol).
Related Practice
Textbook Question
(b) An elemental analysis of the acid indicates that it is composed of 5.89% H, 70.6% C, and 23.5% O by mass. What is its molecular formula?
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Textbook Question
The discovery of hafnium, element number 72, provided
a controversial episode in chemistry. G. Urbain, a French
chemist, claimed in 1911 to have isolated an element
number 72 from a sample of rare earth (elements 58–71)
compounds. However, Niels Bohr believed that hafnium
was more likely to be found along with zirconium than
with the rare earths. D. Coster and G. von Hevesy, working
in Bohr's laboratory in Copenhagen, showed in 1922 that
element 72 was present in a sample of Norwegian zircon,
an ore of zirconium. (The name hafnium comes from the
Latin name for Copenhagen, Hafnia).
(c) Solid zirconium
dioxide, ZrO2, reacts with chlorine gas in the presence
of carbon. The products of the reaction are ZrCl4 and two
gases, CO2 and CO in the ratio 1:2. Write a balanced chemical
equation for the reaction.
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Textbook Question
A sample of 8.69 g of Zn1OH22 is added to 155.0 mL of 0.750 M H2SO4. (c) How many moles of ZnSO4 are present after the reaction is complete?
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Textbook Question
In 2014, a major chemical leak at a facility in West Virginia released 28,390 L of MCHM (4-methylcyclohexylmethanol, C8H16O) into the Elk River. The density of MCHM is 0.9074 g/mL. (a) Calculate the initial molarity of MCHM in the river, assuming that the first part of the river is 2.00 m deep, 90.0 m wide, and 90.0 m long.
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Textbook Question
Ritalin is the trade name of a drug, methylphenidate, used
to treat attention-deficit/hyperactivity disorder in young
adults. The chemical structure of methylphenidate is
(c) Ritalin has a half-life of 3 hours in the blood,
which means that after 3 hours the concentration in the
blood has decreased by half of its initial value. For the
man in part (b), what is the concentration of Ritalin in
his blood after 6 hours?
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