Chemistry
Solutions and pH Chemistry
400 Questions
Solutions and pH chemistry focus on the acidity or alkalinity of various substances, from human urine to acidic soils. Questions involve titration calculations, molarity determination, and understanding mole fractions. This topic is a staple in the chemistry sections of state and national level competitive exams.
Calculating solution molarityMole fraction calculationpH value interpretationAcidic soils and pHTitration and neutralization
Solutions and pH Chemistry Questions
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Hydrochloric acid
-
Sodium chloride
-
Magnesium hydroxide
-
Acetic acid
-
Sodium hydroxide
B
Correct answer
Explanation
This is the correct option. Sodium chloride has a pH of exactly 7.
-
Ammonium chloride
-
Potassium sulphate
-
Ammonium sulphate
-
Sodium carbonate
-
Sodium acetate
B
Correct answer
Explanation
This is the correct option. Potassium sulphate will give a neutral solution because it is formed from a strong acid (sulphuric acid) and a strong base (potassium hydroxide).
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1 x 10-12
-
1 x 10-2
-
1 x 10-7
-
1 x 10-4
B
Correct answer
Explanation
Using pH = -log[H+], when pH = 2, [H+] = 10^(-2) = 1 × 10^(-2) moles per litre. Option A would give pH 12, option C gives pH 7 (neutral), and option D gives pH 4.
B
Correct answer
Explanation
The relation between molarity (M) and mass percent (%) is given by
M = (% x 10 x d) / MW
Where MW = molecular weight of solute and d = density of solution.
Therefore, d = M x MW / (% x 10)= 2.30 x 98 / 25.8 x 10= 0.874 g mL
-1.
-
3.62 M
-
2.92 M
-
0.82 M
-
4.02 M
-
5.61 M
A
Correct answer
Explanation
Molarity of a solution (M) = n/V
Where n = number of moles of urea = 210/60 = 3.5 molV = volume of the solution = mass of solution / density of solution= (210 + 1000) g/1.25 g mL
-1 = 968 mL = 0.968 L.
Therefore, molarity (M) = 3.5 mol/0.968 L = 3.62 mol L
-1
-
acidic
-
alkaline
-
neutral
-
no interpretation can be drawn
C
Correct answer
Explanation
Neutral ph scale ranges from 1 to 14
-
basic
-
isotonic
-
acidic
-
neutral
C
Correct answer
Explanation
High hydrogen ion concentration defines acidic solutions (low pH). Neutral solutions have equal H+ and OH- concentrations, while basic solutions have low H+ and high OH- concentration. Isotonic refers to solute concentration equality across a membrane.
C
Correct answer
Explanation
Let E be the equivalent wt. of the acid
∴ Number of gm eq. of acid = 4/E
Number of gm eq. of NaOH = (0.5 x 40)/1000
According to law of equivalence,
4/E = (0.5 x 40)/1000E = (4 x 1000)/(0.5 x 40) E = 200
-
200 ml
-
400 ml
-
100 ml
-
600 ml
-
300 ml
B
Correct answer
Explanation
By using dilution equation
N
1 V
1 = N
2 V
2(original solution) = (Dilute solution) N
1 = 1/2, V
1 = ?
N
2 = 1/5, V
2 = 1000 ml.
1/2 x V1 = 1/5 x 1000 V
1 = (2 x 1000)/5
= 400 ml
B
Correct answer
Explanation
The pH of rainwater due to the presence of H+ ions formed by the reaction of rainwater with CO2 present in atmosphere will be ~ 5.6.
-
basic
-
neutral
-
acidic
-
None of these
B
Correct answer
Explanation
A pH value of 7 is neutral, so a range of 6.5-7.5 indicates nearly neutral soil. Values below 7 are acidic, while values above 7 are alkaline (basic). Most crops prefer slightly acidic to neutral soil conditions.
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20 gm of ethanol is disolved in 80gm of solvent
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20 gm of ethanol is disolved in 80gm of water
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20 gm of ethanol is disolved 100gm of solvent
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1000 ml of solution contains 20 gm of ethanol
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30 g of glucose is disolved in 100ml. of water
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30 ml of glucose is mixed in 1000 ml. of water
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30 ml of glucose is disolved in water so that the total volume is 100 ml.
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30 ml of glucose is mixed with 70 ml. of water
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more than 7
-
less than 7
-
equal to 7
-
unpredictable
B
Correct answer
Explanation
On the pH scale, a pH of less than 7 is acidic.