The total ratio parts are 5 + 7 = 12. The weight of one part is 360 / 12 = 30 grams. The acid represents 7 parts, so the weight of the acid is 7 * 30 = 210 grams.
3782
Which of the following chemical properties is dependent on the valency of an element?
Equivalent weight is defined as the molar mass of a substance divided by its valency factor (n-factor). Since the valency factor directly influences the calculation of equivalent weight, it is the property that changes based on the valency of the element in a specific reaction.
3783
Buffer capacity when 0.01 moles of NaOH are added, causing pH to shift from 4.745 to 4.832?
Buffer capacity is calculated as moles of NaOH added per unit change in pH. Here, 0.01 moles cause a 0.087 pH change, so buffer capacity = 0.01 / 0.087 = 0.115.
3784
Why does lime water turn milky when carbon dioxide gas is bubbled through it?
Lime water is a solution of calcium hydroxide. When carbon dioxide reacts with calcium hydroxide, it forms insoluble calcium carbonate (CaCO3). The formation of this white precipitate causes the solution to appear milky.
3785
Match the following pH characteristics with their corresponding values: (a) 10^-7, (b) > 7, (c) < 7, (d) 7.
The matches are: (a) 10^-7 represents the hydrogen ion concentration in pure water (4), (b) > 7 indicates an alkaline solution (3), (c) < 7 indicates an acidic solution (2), and (d) 7 is the pH value of a neutral solution (1). Thus, the correct mapping is a-4, b-3, c-2, d-1.
3786
Which of the following pH values is incorrectly matched with its corresponding substance?
The pH of pure water at 25°C is 7.0, not 7.5. A pH of 7.5 would indicate a slightly basic solution. The other values provided (blood at 7.4, vinegar at 2.2, and milk at 6.6) are standard approximate values for these substances.
3787
What is the typical pH range for an alkaline solution?
The pH scale ranges from 0 to 14. A solution is considered neutral at pH 7. Solutions with a pH value less than 7 are acidic, while solutions with a pH value greater than 7 are alkaline (basic). Therefore, an alkaline solution must have a pH greater than 7, reflecting a lower concentration of hydrogen ions compared to hydroxide ions.
3788
Which of the following values represents a possible pH for an acidic solution?
The pH scale defines solutions with a pH less than 7 as acidic, a pH of 7 as neutral, and a pH greater than 7 as basic. Among the provided options, only 6 is less than 7, which characterizes an acidic solution. Values of 7, 8, and 9 represent neutral and basic conditions, respectively.
3789
What is the recommended pH range for potable drinking water according to standard safety guidelines?
While the WHO and many national standards suggest a broader range of 6.5 to 8.5 for water quality, this specific question identifies 6.5 to 7.0 as the target range, likely focusing on neutral to slightly acidic conditions often cited in specific academic curricula.
3790
Evaluate the following statements regarding the dilution of hydrochloric acid: Statement I: Adding water to an aqueous HCl solution decreases the pH. Statement II: Adding water suppresses the ionization of HCl.
Adding water to an acid increases the volume, decreasing the concentration of H+ ions, which raises the pH (making it less acidic). Statement II is false because HCl is a strong acid that is already fully dissociated in water; adding water does not suppress its ionization.
