1.
Ionic solutes present in the urine cause protons to be released from a polyelectrolyte. As the protons are released the decreases and produces a color change of the bromthymol blue indicator from blue-green to yellow-green.
Correct Answer
E. Specific gravity
Explanation
Ionic solutes present in the urine can affect the specific gravity of the urine. When these solutes interact with a polyelectrolyte, they cause the release of protons. This release of protons can then lead to a decrease in the specific gravity of the urine. The decrease in specific gravity is accompanied by a color change of the bromthymol blue indicator from blue-green to yellow-green. Therefore, the specific gravity of the urine can be determined by observing this color change.
2.
Double indicator system. Indicators methyl red and bromthymol blue are used to give distinct color changes from orange to green to blue.
Correct Answer
B. pH
Explanation
The correct answer is pH because the question mentions the use of indicators methyl red and bromthymol blue, which are commonly used to determine pH levels. These indicators change color depending on the acidity or alkalinity of a solution, with methyl red indicating acidic conditions (orange) and bromthymol blue indicating alkaline conditions (green to blue). Therefore, the answer pH is most likely related to the color changes observed when using these indicators.
3.
Pseudoperoxidase activity of heme moiety. The chromogen reacts with peroxide in the presence of hemoglobin or myoglobin to become oxidized and produce a color change from yellow to green.
Correct Answer
D. Blood
Explanation
The correct answer is "Blood." The explanation for this answer is that the pseudoperoxidase activity of the heme moiety in hemoglobin or myoglobin causes a color change in the chromogen when it reacts with peroxide. This color change is from yellow to green, indicating the presence of blood. Therefore, the presence of blood can be detected by observing this color change.
4.
The action of ______ to cleave an ester and form an aromatic compound is followed by an azocoupling reaction of the aromatic amine formed with a diazonium salt on the reagent pad. The azo dye produce causes a color change from beige to violet.
Correct Answer
D. Leukocyte esterase
Explanation
Leukocyte esterase is an enzyme that is produced by white blood cells (leukocytes). In this context, the action of leukocyte esterase is being referred to as the action that cleaves an ester and forms an aromatic compound. This action is followed by an azocoupling reaction of the aromatic amine formed with a diazonium salt on the reagent pad. The resulting azo dye produced causes a color change from beige to violet. Therefore, leukocyte esterase is the correct answer because it is the enzyme responsible for the specific action described in the question.
5.
Diazotization reaction of ________ with an aromatic amine to produce a diazonium salt is followed by an azocoupling reaction of this diazonium salt with an aromatic compound on the reagent pad. The azo dye produces causes a color change from white to pink.
Correct Answer
D. Nitrite
Explanation
The given information suggests that the reaction involves the diazotization of a compound with an aromatic amine to form a diazonium salt. This diazonium salt then undergoes an azocoupling reaction with an aromatic compound on the reagent pad. The resulting azo dye causes a color change from white to pink. Among the options given, nitrite is known to undergo diazotization reactions and form diazonium salts. Therefore, nitrite is the most suitable compound to fit the given description.
6.
Sulfanilamide or p-arsanilic acid  is the amine used for what test?
Correct Answer
B. Nitrite
Explanation
Sulfanilamide or p-arsanilic acid is used for the nitrite test. This test is commonly used to detect the presence of nitrites in a sample. Nitrites can be harmful if consumed in high amounts, so it is important to test for their presence, especially in food and water. Sulfanilamide or p-arsanilic acid reacts with nitrites to produce a colored compound, which can be measured to determine the concentration of nitrites in the sample.
7.
The error of indicators. When the pH is held constant by a buffer (pH 3.0) indicator dyes release H+ ions because of the ______ present. Color changes from yellow to blue-green.
Correct Answer
C. Protein
Explanation
When the pH is held constant by a buffer at pH 3.0, indicator dyes release H+ ions because of the presence of protein. This is because proteins can act as weak acids or bases and can donate or accept protons (H+ ions) depending on the pH of the solution. In this case, the protein present in the solution is causing the indicator dye to release H+ ions, resulting in a color change from yellow to blue-green.
8.
Double-sequential enzyme reaction. Glucose oxidase on a reagent pad catalyzes the oxidation of glucose to form hydrogen peroxide. The hydrogen peroxide formed in the first reaction oxidizes the chromogen on the reagent pad. The second reaction is catalyzed by a peroxidase provided on the pad. The color change differs from the chromogen used.
Correct Answer
E. Glucose
Explanation
The given information states that the reagent pad contains glucose oxidase, which catalyzes the oxidation of glucose to form hydrogen peroxide. The hydrogen peroxide then reacts with the chromogen on the pad, causing a color change. This suggests that the reagent pad is used to test for the presence of glucose. Therefore, the correct answer is Glucose.
9.
Legal test- nitroprussie reaction. Acetoacetic acid in alkaline medium reacts with nitroferricyanide to produce a color change from beige to purple. The chemstrip and Rapignost reagent strips include glycine in the reagent pad for the reaction and detection of acetone; Multistix strips do not.
Correct Answer
B. Ketones
Explanation
The presence of ketones in the sample can be detected using the nitroprussie reaction. Acetoacetic acid, which is a ketone, reacts with nitroferricyanide in an alkaline medium to produce a color change from beige to purple. The chemstrip and Rapignost reagent strips include glycine in the reagent pad, which helps in the reaction and detection of acetone, a type of ketone. However, Multistix strips do not include glycine in the reagent pad, and therefore cannot detect ketones. Therefore, the correct answer is Ketones.
10.
Azocoupling reaction of ______ with a diazonium salt in an acid medium to form an azo dye. Color changes from light tan to beige or light pink observed. dichlorobenzene diazonium tetrafluoroborate may be used.
Correct Answer
E. Bilirubin
Explanation
Bilirubin is a yellow pigment that is formed during the breakdown of red blood cells. In an azocoupling reaction, bilirubin reacts with a diazonium salt in an acid medium to form an azo dye. This reaction results in a color change from light tan to beige or light pink, indicating the formation of the azo dye. The use of dichlorobenzene diazonium tetrafluoroborate as the diazonium salt suggests that this reaction can be carried out in a non-aqueous solvent.
11.
Azocoupling reaction of _________ with diazonium salt in an acid medium to form an azo dye. Color changes from light pink to dark pink are observed. It reacts with Ehrlich reagent with p-dimethylaminobenzaldehye.
Correct Answer
B. Urobilinogen
Explanation
The correct answer is Urobilinogen. Urobilinogen undergoes an azocoupling reaction with diazonium salt in an acid medium to form an azo dye. This reaction causes a color change from light pink to dark pink. Urobilinogen also reacts with Ehrlich reagent, specifically with p-dimethylaminobenzaldehyde.