Q. What is the number of atoms in 2 moles of CaCO3?
A.
6.022 x 10^23
B.
1.2044 x 10^24
C.
3.011 x 10^23
D.
1.8066 x 10^24
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Solution
Each CaCO3 has 5 atoms (1 Ca, 1 C, 3 O). Number of atoms = moles x atoms per molecule x Avogadro's number = 2 moles x 5 x 6.022 x 10^23 = 1.206 x 10^24 atoms.
Correct Answer: D — 1.8066 x 10^24
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Q. What is the number of atoms in 2 moles of Na2SO4?
A.
6.022 x 10^23
B.
1.2044 x 10^24
C.
1.2044 x 10^25
D.
3.011 x 10^23
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Solution
Na2SO4 has 2 Na + 1 S + 4 O = 7 atoms. Number of atoms = moles x atoms per mole = 2 moles x 7 atoms = 14 atoms = 1.2044 x 10^24 atoms.
Correct Answer: B — 1.2044 x 10^24
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Q. What is the number of atoms in 2 moles of NaCl? (2044)
A.
6.022 x 10^23
B.
1.2044 x 10^24
C.
1.2044 x 10^25
D.
3.011 x 10^23
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Solution
Each NaCl unit has 2 atoms (Na and Cl). Therefore, 2 moles of NaCl contain 2 x 6.022 x 10^23 x 2 = 1.2044 x 10^24 atoms.
Correct Answer: B — 1.2044 x 10^24
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Q. What is the number of moles in 10 grams of Na?
A.
0.43
B.
0.22
C.
0.5
D.
0.1
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Solution
Molar mass of Na = 23 g/mol. Number of moles = mass / molar mass = 10 g / 23 g/mol = 0.43 moles.
Correct Answer: A — 0.43
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Q. What is the number of moles in 10 grams of NaOH?
A.
0.25
B.
0.5
C.
0.75
D.
1
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Solution
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol. Number of moles = mass/molar mass = 10 g / 40 g/mol = 0.25 moles.
Correct Answer: B — 0.5
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Q. What is the number of moles in 100 grams of NaOH?
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Solution
Molar mass of NaOH = 23 + 16 + 1 = 40 g/mol. Number of moles = mass/molar mass = 100 g / 40 g/mol = 2.5 moles.
Correct Answer: A — 1
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Q. What is the number of moles in 180 grams of glucose (C6H12O6)?
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Solution
Molar mass of C6H12O6 = 6*12 + 12*1 + 6*16 = 180 g/mol. Number of moles = mass/molar mass = 180 g / 180 g/mol = 1 mole.
Correct Answer: A — 1
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Q. What is the number of moles in 44 grams of CO2?
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Solution
Molar mass of CO2 = 12 + 16*2 = 44 g/mol. Number of moles = mass/molar mass = 44 g / 44 g/mol = 1 mole.
Correct Answer: A — 1
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Q. What is the number of moles in 5 liters of a 2 M NaCl solution?
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Solution
Moles = Molarity x Volume = 2 moles/L x 5 L = 10 moles.
Correct Answer: A — 2.5
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Q. What is the order of the reaction if the rate constant has the unit L/mol·s?
A.
Zero order
B.
First order
C.
Second order
D.
Third order
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Solution
If the rate constant has the unit L/mol·s, the reaction is second order.
Correct Answer: C — Second order
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Q. What is the osmotic pressure of a 0.2 M NaCl solution at 25 °C? (R = 0.0821 L atm/(K mol))
A.
4.92 atm
B.
2.46 atm
C.
1.23 atm
D.
0.61 atm
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Solution
Osmotic pressure = iCRT = 2 * 0.2 * 0.0821 * 298 = 4.92 atm (i = 2 for NaCl)
Correct Answer: A — 4.92 atm
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Q. What is the osmotic pressure of a solution containing 0.2 moles of solute in 1 liter of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
4.92 atm
B.
1.64 atm
C.
0.82 atm
D.
2.46 atm
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Solution
Osmotic pressure = (n/V)RT = (0.2/1) * 0.0821 * 298 = 4.92 atm.
Correct Answer: A — 4.92 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 1 L of water at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
12.3 atm
B.
1.23 atm
C.
0.5 atm
D.
2.5 atm
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Solution
Osmotic pressure (π) = nRT/V = (0.5 moles * 0.0821 * 298) / 1 = 12.3 atm.
Correct Answer: B — 1.23 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 1 liter of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
12.3 atm
B.
0.5 atm
C.
1.0 atm
D.
2.5 atm
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Solution
Osmotic pressure (π) = nRT/V = (0.5 mol)(0.0821 L·atm/(K·mol))(298 K) = 12.3 atm.
Correct Answer: A — 12.3 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 1 liter of water at 25 °C?
A.
12.3 atm
B.
24.6 atm
C.
6.1 atm
D.
3.1 atm
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Solution
Osmotic pressure (π) = iCRT = 1 * 0.5 * 0.0821 * 298 = 12.3 atm.
Correct Answer: A — 12.3 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 1 L of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
12.3 atm
B.
10.2 atm
C.
8.2 atm
D.
6.1 atm
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Solution
Osmotic pressure (π) = nRT/V = (0.5 moles)(0.0821 L·atm/(K·mol))(298 K) = 12.3 atm.
Correct Answer: A — 12.3 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 2 liters of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
6.13 atm
B.
12.26 atm
C.
3.07 atm
D.
1.54 atm
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Solution
Osmotic pressure (π) = nRT/V = (0.5 moles)(0.0821 L·atm/(K·mol))(298 K) / 2 L = 6.13 atm.
Correct Answer: A — 6.13 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of glucose in 2 liters of solution? (R = 0.0821 L·atm/(K·mol), T = 298 K)
A.
6.14 atm
B.
12.28 atm
C.
3.07 atm
D.
1.54 atm
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Solution
Osmotic pressure (π) = (n/V)RT = (0.5/2) * 0.0821 * 298 = 6.14 atm.
Correct Answer: A — 6.14 atm
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Q. What is the osmotic pressure of a solution containing 0.5 moles of solute in 2 liters of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
10.25 atm
B.
5.12 atm
C.
2.03 atm
D.
1.23 atm
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Solution
Osmotic pressure (π) = nRT/V = (0.5 moles * 0.0821 * 298) / 2 = 12.21 atm.
Correct Answer: B — 5.12 atm
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Q. What is the osmotic pressure of a solution containing 1 mole of glucose in 2 liters of solution at 25 °C? (R = 0.0821 L·atm/(K·mol))
A.
0.41 atm
B.
0.82 atm
C.
1.23 atm
D.
1.64 atm
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Solution
Osmotic pressure (π) = nRT/V = (1 mol)(0.0821 L·atm/(K·mol))(298 K) / 2 L = 0.82 atm.
Correct Answer: B — 0.82 atm
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Q. What is the osmotic pressure of a solution directly proportional to?
A.
Temperature
B.
Concentration of solute
C.
Volume of solvent
D.
Both A and B
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Solution
Osmotic pressure is directly proportional to both the temperature and the concentration of solute.
Correct Answer: D — Both A and B
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Q. What is the oxidation state of chlorine in NaClO3?
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Solution
In NaClO3, chlorine has an oxidation state of +5.
Correct Answer: C — +5
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Q. What is the oxidation state of chromium in K2Cr2O7?
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Solution
In K2Cr2O7, the total oxidation state of the two potassium ions and seven oxygen ions is -12, leading to +6 for each chromium.
Correct Answer: C — +6
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Q. What is the oxidation state of chromium in K2[Cr2O7]?
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Solution
In K2[Cr2O7], the overall charge is 0. Each potassium (K) has a +1 charge, and each oxygen (O) has a -2 charge. Solving for chromium gives an oxidation state of +6.
Correct Answer: C — +6
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Q. What is the oxidation state of chromium in the complex [Cr(NH3)4Cl2]Cl?
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Solution
Let the oxidation state of Cr be x. The equation is x + 4(0) + 2(-1) = +1 (from Cl). Solving gives x = +3.
Correct Answer: B — +3
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Q. What is the oxidation state of chromium in [Cr(NH3)4Cl2]+?
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Solution
Let the oxidation state of Cr be x. The equation is x + 4(0) + 2(-1) = +1. Solving gives x = +3.
Correct Answer: B — +3
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Q. What is the oxidation state of chromium in [Cr(NH3)4Cl2]Cl?
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Solution
Let the oxidation state of Cr be x. The equation is x + 4(0) + 2(-1) = +1. Solving gives x = +3.
Correct Answer: B — +3
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Q. What is the oxidation state of chromium in [Cr(NH3)6]Cl3?
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Solution
The complex is neutral, and the three chloride ions contribute -3 charge. Therefore, the oxidation state of Cr must be +3.
Correct Answer: B — +3
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Q. What is the oxidation state of hydrogen in H2O?
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Solution
In water (H2O), the oxidation state of hydrogen is +1.
Correct Answer: A — +1
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Q. What is the oxidation state of hydrogen in metal hydrides?
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Solution
In metal hydrides, hydrogen has an oxidation state of -1.
Correct Answer: C — -1
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