Exam #2 Review
Which element is reduced in the following reaction? 3Fe(NO3)2 (aq) + 2Al (s) ----> 3Fe (s) + 2Al(NO3)2 (aq)
Fe is reduced
How many moles of hydrogen atoms are in 2 mol of dimethylsulfoxide? (C2H6SO)
There are 12 moles of hydrogen atoms.
The mass of one molecule of C3H6O is _____?
58 amu or 9.644 x 10^-23 g
Calculate the % hydrogen in glucose (C6H12O6)
6.73 % H
What type of reaction is the following? MgCl2 (aq) + NaCO3 (aq) ---> MgCO3 (s) + 2NaCl (aq)
precipitation reaction
What is the oxidation number of carbon in C2O4 (charge of 2-)
+3
What is the oxidation number of sulfur in H2SO4?
+6
What is the oxidation number of nitrogen in N2H4?
-2
What mass of KCl is needed to precipitate the silver ions from 35.0 mL of .2 M AgNO3 solution?
.225 g of KCl
A solution has molar concentration 2.00 M. A .200-L sample of this solution is diluted to a volume of .800L. What is the molar concentration of the diluted solution?
.5 M
Calcium carbide (CaC2) reacts with water to produce acetylene and calcium hydroxide: CaC2 (s) + 2H2O (g) ---> Ca(OH)2 (aq) + C2H2 (g) Calculate the mass of water required to make 39.00 g of calcium hydroxide.
18.97 g H2O
How many moles of NH3 can be produced by the reaction of 3.5 mol of N2 with 4.0 mol of H2 via the equation below? (there is a limiting reactant) N2 + 3H2 ----> 2NH3
2.667 moles of NH3 can be produced
What is the mass percentage of H in ethane? (C2H6)
20.15 % (6.06 g/ 30.08 g)
How many moles of CO2 are produced when .425 mole of octane burns in the following reaction? 2C8H18 (l) + 25O2 (g) ----> 16CO2 (g) + 18H2O (g)
3.4 moles of CO2
A solution is prepared by dissolving 80.0 g of sodium hydroxide in water to a total volume of .500 L. The formula weight of NaOH is 40.0 g/mol. What is the molar concentration of the solution?
4.0 M NaOH
If the formula weight of C3H6O is 58.08, what is the mass of 1.5 moles of C3H6O?
87.12 g (58.08 g x 1 mol C3H6O/58.08 g x 1.5)
What is a base?
A substance that increases the concentration of OH when dissolved in water. It also accepts a H+ ion.
Predict the product in the combination reaction below. Al (s) + N2 (g) --->
AlN
A molecule has an empirical formula of CH2 and a molecular mass of 84 amu. What is its formula?
C6H12 (84 amu/ 14.03 amu = 6, so multiply everything by 6)
What is the empirical formula of a compound that contains 40.0% C, 6.70% H, and 53.3% O by mass?
CH2O
The balanced net ionic equation for precipitation of CaCO3 when aqueous solutions of Na2CO3 and CaCl2 are mixed is ____.
Ca (charge 2+) (aq) + CO3 (aq) ---> CaCO3 (s)
The balanced net ionic equation for precipitation of CaCO3 when aqueous solutions of CaCl2 and LiCO3 are mixed is ______.
Ca (charge 2+) (aq) + CO3 (charge 2-) (aq) ---> CaCO3 (s)
Which ion(s) is/are spectator ions in the following reaction? Mg(OH)2 (s) + 2HCl (aq) ---> MgCl2 (aq) + 2H2O (l)
Cl- is a spectator ion
Which of the following is not an electrolyte? A) KOH B) NaCl C) HCl D) CH4 E) H2SO4
D) CH4
What dissolved species are present in a solution of K2CO3?
K (1+) ions and CO3 (charge 2-) ions
Which ion(s) is/are spectator ions in the following reaction? BaCl2 (aq) + Na2SO4 (aq) ---> BaSO4 (s) + 2NaCl (aq)
Na+ and Cl- are both spectator ions
Which element is oxidized in the following reaction? P4 (s) + 10HClO (aq) + 6H2O (l) ---> 4H3PO4 (aq) + 10HCl (aq)
P is oxidized
What is the net ionic equation of ZnBr2 (aq) + 2KOH (aq) ---> Zn(OH)2 (s) + 2KBr (aq)
Zn (charge 2+) (aq) + 2OH (charge 1-) (aq) ---> Zn(OH)2 (s)
In which of the following does hydrogen have oxidation number -1?
a.) KH
In a titration of 20.00 mL of 0.5000 M HI, ______ mL of a 2.000 M KOH solution is required for neutralization. a. 40.00 b. 5.000 c. 20.00 d. 80.00 e. 10.00
b. 5.000
Which of the following is a strong electrolyte? a. H3PO4 b. HBr c. NH3 d. CH3OH e. HF
b. HBr
What type of reaction is the following? Mg (s) + 2HCl (aq) ----> MgCl2 (aq) + H2 (g) a. combination b. oxidation/reduction (redox) c. acid/base d. decomposition e. precipitation
b. oxidation/reduction (redox)
A solution of a strong electrolyte exists predominantly as ________ in solution. a. molecules b. atoms c. ions d. isotopes e. electrons
c. ions
What type of reaction is the following? Ca(OH)2 (aq) + 2HBr (aq) ---> CaBr2 (aq) + 2H2O (l)
neutralization (acid/base)
What type of reaction is the following? Mg(OH)2 (s) + 2HNO3 (aq) ---> Mg(NO3)2 (aq) + 2H2O (l)
neutralization (acid/base)
What type of reaction is the following? 2HCl (aq) + 2Ca (s) ---> CaCl2 (aq) + H2 (g)
redox reaction
What type of reaction is the following? 2HCl (aq) + 2Li (s) ---> 2LiCl (aq) + H2 (g)
redox reaction