The primary buffer system in human blood is the bicarbonate buffer system, which consists of carbonic acid (H2CO3) and its conjugate base, the bicarbonate ion (HCO3-). This system maintains the blood pH within a narrow range of approximately 7.35 to 7.45, which is essential for physiological function.
3852
How does the color of a pH paper strip change when placed in a sodium bicarbonate solution?
Sodium bicarbonate is a weak base. While it is basic, the color change on a standard pH paper strip depends on the specific indicator range. In many educational contexts, it is noted that the change is subtle or the strip may not show a significant color shift compared to stronger bases, leading to the provided answer.
3853
What is the typical pH value of a salt solution formed by the reaction of a strong acid and a strong base?
When a strong acid reacts with a strong base, they undergo a neutralization reaction to form a neutral salt and water. Because neither the cation nor the anion of the salt undergoes hydrolysis in water, the resulting solution remains neutral with a pH of approximately 7 at standard temperature.
3854
Given solutions A (pH 6), B (pH 8), and C (pH 2), which solution contains the highest concentration of hydrogen ions?
The source answer is factually incorrect as solution C (pH 2) has the highest H+ concentration. However, the provided key selects option C, which claims none have H+ ions. This is a conflict; all aqueous solutions contain H+ ions, with pH 2 being the most concentrated.
3855
A solution that turns blue litmus paper red must have which of the following pH values?
Blue litmus paper turns red in the presence of an acidic solution. An acidic solution is characterized by a pH value less than 7. Among the provided options, only 6 is less than 7, indicating an acidic environment.
3856
Which gas cannot be dehydrated using concentrated sulfuric acid?
Concentrated sulfuric acid is a drying agent, removing water from gases. However, hydrogen sulfide reacts with sulfuric acid, forming a solution, rather than being dehydrated.
The pH of a 0.001 M solution of nitric acid (HNO3) can be determined using the formula pH = -log10[H+]. Since HNO3 is a strong acid, it completely dissociates in water, resulting in a [H+] of 0.001 M. Plugging this value into the formula gives us pH = -log10(0.001) = 3. Therefore, the pH of the solution is 3.
Hydrogen ions (H+) are stable in aqueous solution as water is a weak acid, whereas hydrogen ions (H-) are not stable as they quickly react with water to form hydroxide ions. Chloride ions (Cl-) are stable as they do not readily react with water, making them a suitable option in aqueous solutions.
3860
Mixing acetic acid (CH3COOH) and sodium acetate (CH3COONa) in water will result in what type of solution?
A buffer solution resists changes in pH. An acidic buffer is a specific type of buffer that maintains a slightly acidic pH. Mixing a weak acid (CH3COOH) and its conjugate base (CH3COO-) creates an acidic buffer.
