Q. Calculate the perimeter of a square with side length 4 cm. (2015)
A.
16 cm
B.
12 cm
C.
8 cm
D.
20 cm
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Solution
Perimeter = 4 × side = 4 × 4 cm = 16 cm.
Correct Answer: A — 16 cm
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Q. Calculate the perimeter of a square with side length 6 cm. (2015)
A.
24 cm
B.
20 cm
C.
18 cm
D.
30 cm
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Solution
Perimeter = 4 × side = 4 × 6 = 24 cm.
Correct Answer: A — 24 cm
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Q. Calculate the pH of a 0.01 M solution of NaHCO3. (2023)
A.
8.3
B.
9.0
C.
7.5
D.
8.0
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Solution
NaHCO3 is a weak base. The pH can be calculated using the formula pH = 7 + 0.5(pKa - log[C]). pKa of HCO3- is about 10.3, so pH ≈ 8.3.
Correct Answer: A — 8.3
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Q. Calculate the pH of a 0.05 M NH4Cl solution (Kb for NH3 = 1.8 x 10^-5).
A.
4.75
B.
5.25
C.
5.75
D.
6.25
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Solution
Using the formula for weak bases, pH = 14 - 0.5(pKb - logC) = 14 - 0.5(4.74 - log(0.05)) = 5.25.
Correct Answer: B — 5.25
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Q. Calculate the pH of a 0.1 M acetic acid solution (Ka = 1.8 x 10^-5).
A.
2.87
B.
3.87
C.
4.87
D.
5.87
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Solution
Using the formula for weak acids, pH = 0.5(pKa - log[C]), where pKa = -log(1.8 x 10^-5) ≈ 4.74. Thus, pH = 0.5(4.74 - log(0.1)) = 3.87.
Correct Answer: B — 3.87
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Q. Calculate the pH of a 0.1 M NaOH solution.
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Solution
pOH = -log[OH-] = -log(0.1) = 1, thus pH = 14 - pOH = 14 - 1 = 13.
Correct Answer: C — 14
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Q. Calculate the pH of a 0.2 M solution of KOH.
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Solution
pOH = -log(0.2) = 0.7, thus pH = 14 - 0.7 = 13.3.
Correct Answer: B — 13
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Q. Calculate the pH of a buffer solution containing 0.1 M acetic acid and 0.1 M sodium acetate.
A.
4.76
B.
5.76
C.
6.76
D.
7.76
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Solution
Using Henderson-Hasselbalch equation: pH = pKa + log([A-]/[HA]); pKa of acetic acid = 4.76, so pH = 4.76 + log(1) = 4.76
Correct Answer: B — 5.76
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Q. Calculate the pH of a solution that is 0.1 M in acetic acid (Ka = 1.8 x 10^-5).
A.
2.87
B.
3.87
C.
4.87
D.
5.87
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Solution
Using the formula for weak acids, pH = 0.5(pKa - logC) = 0.5(4.74 - log(0.1)) = 3.87.
Correct Answer: B — 3.87
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Q. Calculate the range of the data set: 12, 15, 22, 30, 5.
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Solution
Range = Maximum - Minimum = 30 - 5 = 25.
Correct Answer: A — 25
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Q. Calculate the range of the data set: 4, 8, 15, 16, 23, 42.
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Solution
Range = Maximum - Minimum = 42 - 4 = 38.
Correct Answer: A — 38
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Q. Calculate the range of the data set: 8, 12, 15, 20, 22.
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Solution
Range = Max - Min = 22 - 8 = 14.
Correct Answer: A — 10
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Q. Calculate the range of the following data set: 12, 15, 20, 22, 30.
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Solution
Range = Maximum - Minimum = 30 - 12 = 18.
Correct Answer: C — 18
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Q. Calculate the range of the following data set: 15, 22, 8, 19, 30.
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Solution
Range = max - min = 30 - 8 = 22.
Correct Answer: D — 30
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Q. Calculate the range of the following data set: 4, 8, 15, 16, 23, 42.
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Solution
Range = Maximum - Minimum = 42 - 4 = 38.
Correct Answer: A — 38
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Q. Calculate the range of the following data set: 8, 12, 15, 7, 10.
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Solution
Range = Maximum - Minimum = 15 - 7 = 8.
Correct Answer: A — 5
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Q. Calculate the RMS speed of a gas with molar mass 0.028 kg/mol at 300 K. (R = 8.314 J/(mol K))
A.
500 m/s
B.
600 m/s
C.
700 m/s
D.
800 m/s
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Solution
Using v_rms = sqrt(3RT/M), we find v_rms = sqrt(3 * 8.314 * 300 / 0.028) = 600 m/s.
Correct Answer: B — 600 m/s
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Q. Calculate the scalar product of A = (1, 1, 1) and B = (2, 2, 2).
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Solution
A · B = 1*2 + 1*2 + 1*2 = 2 + 2 + 2 = 6.
Correct Answer: D — 6
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Q. Calculate the scalar product of the vectors (1, 0, 0) and (0, 1, 0).
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Solution
Scalar product = 1*0 + 0*1 + 0*0 = 0.
Correct Answer: A — 0
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Q. Calculate the scalar product of the vectors (1, 2, 3) and (4, 5, 6).
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Solution
Scalar product = 1*4 + 2*5 + 3*6 = 4 + 10 + 18 = 32.
Correct Answer: A — 32
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Q. Calculate the scalar product of the vectors (2, 3, 4) and (4, 3, 2).
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Solution
Scalar product = 2*4 + 3*3 + 4*2 = 8 + 9 + 8 = 25.
Correct Answer: A — 28
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Q. Calculate the scalar product of the vectors (3, 0, -3) and (1, 2, 1).
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Solution
Scalar product = 3*1 + 0*2 + (-3)*1 = 3 + 0 - 3 = 0.
Correct Answer: A — 0
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Q. Calculate the scalar product of the vectors A = (1, 2, 3) and B = (4, 5, 6).
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Solution
A · B = 1*4 + 2*5 + 3*6 = 4 + 10 + 18 = 32.
Correct Answer: B — 30
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Q. Calculate the scalar product of the vectors A = (4, -1, 2) and B = (2, 3, 1).
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Solution
A · B = 4*2 + (-1)*3 + 2*1 = 8 - 3 + 2 = 7.
Correct Answer: A — 10
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Q. Calculate the scalar product of the vectors K = (0, 1, 2) and L = (3, 4, 5).
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Solution
K · L = 0*3 + 1*4 + 2*5 = 0 + 4 + 10 = 14.
Correct Answer: A — 10
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Q. Calculate the term containing x^3 in the expansion of (2x + 5)^6. (2000)
A.
1500
B.
1800
C.
2000
D.
2500
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Solution
The term containing x^3 is C(6,3) * (2)^3 * (5)^(6-3) = 20 * 8 * 125 = 20000.
Correct Answer: B — 1800
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Q. Calculate the term containing x^3 in the expansion of (x + 2)^7.
A.
56
B.
84
C.
112
D.
128
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Solution
The term containing x^3 is C(7,3) * (2)^4 = 35 * 16 = 560.
Correct Answer: B — 84
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Q. Calculate the term independent of x in the expansion of (2x - 3)^5.
A.
-243
B.
0
C.
243
D.
81
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Solution
The term independent of x is C(5,5) * (2x)^0 * (-3)^5 = 1 * 1 * (-243) = -243.
Correct Answer: A — -243
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Q. Calculate the term independent of x in the expansion of (2x^2 - 3x + 4)^3.
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Solution
The term independent of x occurs when the powers of x cancel out. The term is C(3,0)(4)^3 + C(3,1)(-3x)(4)^2 + C(3,2)(-3x)^2(4) + C(3,3)(-3x)^3 = 64 - 36 + 0 + 0 = 28.
Correct Answer: B — 24
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Q. Calculate the term independent of x in the expansion of (2x^2 - 3x + 4)^5.
A.
80
B.
120
C.
160
D.
200
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Solution
The term independent of x occurs when the powers of x cancel out. This can be calculated using the binomial expansion.
Correct Answer: C — 160
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