Answer and Explanation:
Aspirin is odorless, but when left exposed to air in the environment, it gradually hydrolyzes into salicylic acid and acetic acid as that is the precursor for synthesizing Aspirin.
Using this hydrolyzed aspirin for titration would not be advised, because it would affect the reading of the titration. Ordinarily, apsirin is a weak acid and direct titration of aspirin is problematic because it hydrolyzes pretty fast to salicylic acid— leading to an unwanted side reaction which may or may not go to completion. Therefore, excess base must be added and heat is supplied to the mixture so that neutralization and hydrolysis are complete. The remaining base is then titrated. This is called back titration.
Now, in back titration, instead of using solution whose concentration is expected to be known, we rather use excess volume of reactant which has been left over after the completion of a reaction with the analyte.
In this case, we use an alkali, preferably NaOH (1.0 mol/dm³). Te unused NaOH remaining after the hydrolysis is titrated against a standard HCl (0.1 mol/dm³). Then from the reaction equation of the aspirin and sodium hydroxide, the amount of NaOH required for the hydrolysis can be calculated.
Answering whether the titration goes up or down, it would be observed that the titration reading would GO DOWN because the exposed aspirin used has experienced some form of hydrolysis before it was used for titration, so the hydrolysis reaction it would undergo with acetyl-salicylic acid would be minimal, and this would affect the titration reading.
But if the aspirin wasn't left exposed to the environment, the reading would go up since more hydrolysis would take place in this case.
Answer:
Oxygen.
Explanation:
Oxygen is a chemical element that aides in the burning of materials and it is needed for humans to breathe.
Cellular respiration can be defined as a series of metabolic reactions that typically occur in cells so as to produce energy in the form of adenosine triphosphate (ATP). During cellular respiration, high energy intermediates are created that can then be oxidized to make adenosine triphosphate (ATP). Therefore, the intermediary products are produced at the glycolysis and citric acid cycle stage through the breathing of oxygen used to obtain energy from the food ingested.
Hence, all cells in living organisms require oxygen and glucose to release energy.
It is recommended only for the second type of candy to be taken off the market.
Based on the background information, if a candy shows a 0,62 Rf value in the chromatography it is considered potentially dangerous, and therefore it should be taken off the market.
The Rf value is calculated using the following formula:
- Rf = Total distance traveled by a component/ Total distance from the pencil line to the solvent front
Now, let's find out if any of the components has an Rf equal to 0,62.
Note: To determine the distances I measured the image using a ruler and you can do the same, this will not alter the results.
- Sample 1
- Total distance traveled by the component: 6cm
- Total distance: 7 cm
- Rf : 6 cm/ 7 cm = 0.85
2. Sample 2
- Total distance traveled by the component: 4.34cm
- Total distance: 7 cm
- Rf : 4.34 cm/ 7 cm = 0.62
This means sample 2 has the 0.62 Rf value and therefore it needs to be taken off the market.
Learn more about chromatography in: brainly.com/question/10296715
Answer:
Option A = sodium and bromine
Explanation:
Sodium is metal while bromine is non metal. The bond formed between them is ionic.
Ionic bond:
Ionic bond is formed by the complete transfer of electron form metal to non metal.
Sodium is belongs to the group one while bromine is present in group seventeen. The number of valance electron of bromine are seven. Bromine require one electron to complete the octet, while sodium lose its one valance electron to gain noble gas stable electronic configuration. Thus sodium transfer its electron to bromine and gain positive charge and bromine gain its electron and form negative ion. The forces present between them are electrostatic forces which are very strong.
Na⁺Br⁻
