Download Practice Problems

10/16/2014

Work through Challenge Problem Set 5, DUE tonight at
11 pm

Midterm Exam 2: Next Tuesday, Oct. 21st:
◦ Bring a NONPROGRAMMABLE Scientific Calculator &
an ORANGE Parscore Sheet
◦ Check out Canvas for Study Guide & Practice Exam
from last year
Practice Problems:
C8H18
______________
Na2C2O4
______________
C7H12
______________
CH3COOH
______________
C6H2CH3(NO2)3
______________
C3H6N3(NO2)3
______________
Practice Problems:
Determine the empirical and molecular formulas for an unknown
compound based on the information provided below:
• Mass Composition Data from Elemental Analysis:
• 51.28 % Carbon
• 9.40 % Hydrogen
• 27.35 % Oxygen
• 11.97 % Nitrogen
• Molar Mass from Mass Spectrometry Data: 234 g/mol
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10/16/2014
Practice Problems:
Determine the empirical and molecular formulas based on the
information provided below:
• 11.800 grams of an unknown sample containing only C, H, & N
is found to have 7.200 g of carbon, & 4.198 g of nitrogen.
• Molar Mass from Mass Spectrometry Data: 354.3 g/mol
Practice Problems:
Write the balanced chemical equations for the reactions below:
• Combustion of butane, C4H10
• Combustion of sucrose, C12H22O11
• Aluminum metal reacts with manganese (IV) oxide to produce
aluminum oxide and manganese metal
• Ammonium phosphate reacts with iron (II) nitrate to produce a
precipitate
• Making potassium nitride from its component elements
• Uranium (VI) fluoride reacts with magnesium metal
Practice Problems:
Write the decomposition for ammonium dichromate to produce
nitrogen gas, water vapor and chromium (III) oxide.
Hint: Dichromate = Cr2O72How many grams of
ammonium dichromate
would be needed to
generate 400. grams of
water from this
decomposition?
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10/16/2014
Practice Problems:
2 Mg + CO2 → 2 MgO + C
If 30 g of Mg was mixed with 30 g of carbon dioxide, what is the
maximum amount of magnesium oxide that could form? In
other words, calculate the theoretical yield of MgO.
FIRST: calculate the limiting reagent by finding the
maximum amount of product (MgO) that could form IF each
reactant was fully consumed.
THEN: compare the amount of product that could form in
each case. The reactant that produces less product is the
limiting reagent & LIMITS the formation of product.
Practice Problems:
Write the balanced chemical equation describing copper (I) oxide
reacting with carbon atoms to form copper metal and carbon dioxide.
• How much copper metal could be produced from 100.0 grams of
copper (I) oxide & 30. grams of carbon?
Practice Problems:
Urea (CH4N2O), a common fertilizer, can be synthesized by the
reaction of ammonia (NH3) with carbon dioxide.
2 NH3(aq) + CO2(aq)
CH4N2O(aq) + H2O(l)
An industrial synthesis of urea begins with 35.8 kg of ammonia &
89 kg of carbon dioxide. What mass of urea could theoretically be
produced from this starting mixture?
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