問題一覧
1
1) Which of the following is not an electrolyte when dissolved in water?
CBr4
2
What is the new concentration (M) of sucrose after O.05 L of a stock 0.0250 M sucrose solution is diluted in a final volume of 0.25 L. 0.125 M 1.25 M 0.00500 M D) 8.00 M E) 2.53 M
0.00500 M
3
Select the number of grams (g) of CO2 formed by the reaction of 0.153 mol C3H8 with excess O2. C3H8(g) + 5 O2(g) → 3 CO2(g) + 4 H2O(g)
20.2 g CO2
4
How many moles of oxide ions are present in a 1 L volume for a 1.27 M solution with Li2O?
1.27 M
5
If 0.5 moles of H2O are reacted, how many moles of C2H2 would be produced in the reaction below? CaC2 (s) + 2H2O (g) → Ca(OH)2 (s) + C2H2 (g)
0.25 moles
6
Which statement is false regarding the molecule MgSO4?
the oxidation number of sulfur is -2
7
Answer
SiH4
8
Determine how many moles of the limiting reactant Cu+ are required to form 100.0 g Cu2S in the balanced reaction below. (Cu2S = 159.2 g/mole) 2Cu+(aq) + S2–(aq) → Cu2S(s)
1.26 mol Cu+
9
Which of the following solutes has a limiting van't Hoff factor of 1 when dissolved in water and likely won’t significantly increase the boiling point or lower the freezing point?
PCl3
10
How much NaCl can be theoretically produced if 1.25 grams of sodium carbonate (Na2CO3) is combined with 0.03 L of 0.2 M HCl in the reaction below? (HCl = 36.5 g/mole; Na2CO3 = 106 g/mole; NaCl = 58 g/mole) 2 HCl(aq) + Na2CO3(s) ➔ 2 NaCl(aq) + H2CO3(aq)
0.348 g
11
Answer
dipole-dipole forces
12
If the molecule that contains the oxidized atom is called the reducing agent, which molecule is the reducing agent for the reaction below? CuO (s) + CO (g) → Cu (s) + CO2 (g)
CO
13
When the acid HCl is mixed with the base KOH, which statement is false?
potassium (K) would be oxidized in the reaction
14
A 0.038 mole sample of magnesium nitride (Mg3N2) is reacted with 0.43 moles of H2O. The actual yield of MgO is 3.60 g. What is the percent yield in the reaction below? (MgO = 40.3 g/mole) Mg3N2 + 3H2O → 2NH3 + 3MgO
78.4
15
Which set of molecular interactions below can’t form hydrogen bonds?
HCl and HF
16
In the generic reaction below, how many moles of reactant B will be consumed if there is 0.5 L of 3M reactant A used? Consider reactant B to be in excess. 2A + 3B ↔ C + 4D
2.3 moles
17
Which of the following reactions is incorrectly classified?
PbO (s) + C (s) ↔ Pb (s) + CO (g) (double-replacement)
18
In which reaction is oxygen oxidized?
2H2O (l) → 2H2 (g) + O2 (g)
19
What is the oxidation number on sulfur in SO32-?
4
20
Answer
it can form hydrogen bonds with the same molecule
21
What is the volume (L) of 0.82 M HCl required to neutralize 1.25 grams of sodium carbonate (Na2CO3) based on the stoichiometry in the reaction below? (HCl = 36.5 g/mole; Na2CO3 = 106 g/mole) 2 HCl(aq) + Na2CO3(s) ➔ 2 NaCl(aq) + H2CO3(aq)
0.029 L