1) When the percent recovery is less than 100%, where is most of the uncovered material...

1) When the percent recovery is less than 100%, where is most of the uncovered material and how might you go about recovering it if you needed to? (three of fewer sentences)

2) Hot filtration was not necessary in the recrystallization of phthalic acid but was necessary in the recrystallization of naphthalene. Why was it necessary in the recrystallization of naphthalene?

Both of these are about a recrystallization experiment.

Solutions

Expert Solution

1) Most losses during recrystallization occur when doing the filtration, because when washing the crystals with the solvent, the solvent dissolves a portion of the crystals. This can be avoided by a second process of crystallization of the washing solvent.

2) Hot filtration is necessary in the recrystallization of naphthalene because the solubility of naphthalene increase with the temperature.

The solubility of naphthalene change depending on the solvent but in all cases, the solubility increase significantly with increasing temperature

For example, the solubility of naphthalene in water at 25°C is 31.6mg/L and the solubility of phthalic acid in water at 25°C is 6000mg/L (0.6g/mL), which means phthalic acid is much more soluble in water at 25°C.

Also, when increase the temperature, the solubility of naphthalene in water, increase as following:

19 mg/L (10 °C)

31.6 mg/L (25 °C)

43.9 mg/L (34.5 °C)

80.9 mg/L (50 °C)

238.1 mg/L (73.4 °C)

queen_honey_blossom answered 1 year ago

Next > < Previous

Related Solutions

When valuing a parent company that owns less than 100 percent of a subsidiary, the minority...

When valuing a parent company that owns less than 100 percent of a subsidiary, the minority interest holder of the subsidiary has a claim on the parent company’s assets. A. True B. False

Q5: When the issue is less than their receipts this will lead to a situation where:

Q5: When the issue is less than their receipts this will lead to a situation where:Select one:a. More Inventoryb. None of the abovec. Shortage of Inventoryd. Zero InventoryQ6: The items which are discarded from a production process are known as:Select one:a. Inventoryb. Repaired itemsc. Rejected itemsd. Spare partsQ7: The items required to produce a product or deliver a service is known as:Select one:a. Rejected itemsb. Repaired itemsc. Spare partsd. Inventory

Audit sampling involves applying an audit procedure to less than 100 percent of the population for...

Audit sampling involves applying an audit procedure to less than 100 percent of the population for the purpose of evaluating some characteristic of the population. The fact that an audit involves sampling is noted in the scope paragraph of the auditor’s report, which contains the phrase “An audit includes examining, on a test basis.” When an auditor uses sampling, an element of uncertainty enters into the auditor’s conclusions. Required: a) Explain why auditor’s still use sampling techniques despite the uncertainties...

Instructions In less than 100 words, summarize the production process of any composite material. Your report...

Instructions In less than 100 words, summarize the production process of any composite material. Your report must include the constituent materials, the fabrication process and the applications of the product

What other examples can you think of where most people have more or less than the...

What other examples can you think of where most people have more or less than the average? This is true of most things with a non-symmetric distribution (e.g., weight, math scores, marathon times) but it is nice to continue the theme of the video in terms of risk (e.g., most have below average risk of a automobile accident, death by violence, or even, say, getting a date).

Iron ppm in hair: why is there a potential to have a percent recovery over 100%...

Iron ppm in hair: why is there a potential to have a percent recovery over 100% even when there is no human error?

Pat went into a bank to cash a check that was for less than $100. The...

Pat went into a bank to cash a check that was for less than $100. The clerk gave Pat bills and coins. Counting the handout, Pat noticed that the clerk had made a mistake, exchanging the number of dollars for the number of cents, and vice versa. Then Pat dropped a nickel (5 cents) on the floor. Surprisingly, the remaining amount (that is, without the nickel) was exactly twice the correct value of the check. How much was the check...

1. What is the result when the quantity of materials used is less than the standard...

1. What is the result when the quantity of materials used is less than the standard quantity? Multiple Choice An unfavorable materials price variance A favorable materials usage variance An unfavorable materials usage variance A favorable materials price variance 2. Which manager is usually held responsible for materials usage variances? Multiple Choice Purchasing agent None of these answers is correct. Production supervisor Marketing manager 3. Flexible budget amounts for variable costs and revenues come from multiplying standard per unit amounts...

Audit sampling involves applying an audit procedure to less than 100 percent of the population for the purpose of evaluating some characteristics of the population.

Audit sampling involves applying an audit procedure to less than 100 percent of the population forthe purpose of evaluating some characteristics of the population. The fact that an audit involvessampling is noted in the scope paragraph of the auditor’s report, which contains the phrase “Anaudit includes examining, on a test basis.” When an auditor uses sampling, an element ofuncertainty enters into the auditor’s conclusions.Required:a) Explain why auditor’s still use sampling techniques despite the uncertainties that areinherent in audit conclusions drawn...

(2) In the United States, more than 50% of banks have less than $100 million in...

(2) In the United States, more than 50% of banks have less than $100 million in assets: T or F? (3) In 1980, there were 14,404 commercial banks in the United States, but now there are 5,116 in 2020: T or F? (4) The U.S. banking industry is highly concentrated compared with other industries in the United States or compared with the banking industry in other countries: T or F? (5) The U.S. banking industry is one of the most...

Subjects