CHEMISTRY COLLEGE

When 225 mg of anthracene was burned in a bomb calorimeter the temperature rose?

Answers

Answer 1
Answer: When it is placed in a bomb calorimeter, it undergoes combustion. The heat of combustion of anthracene is +102 kJ/mol. The positive sign means that the reaction is endothermic. It needs heat from the surroundings to burn anthracene. Therefore, as a result, the temperature decreases.

Related Questions

MIDDLE SCHOOL

How many moles of chromium III nitrate are produced When chromium reacts with 0.85 moles of lead for nitrate to produce chromium three nitrate and lead

Answers

0.85 moles formula units of lead nitrate will produce 0.57 moles formula units of chromium (III) nitrate.

Explanation

Typically, the oxidation state of Pb in lead nitrate tend to be +2. In other words, Pb in lead nitrate tends to exist as ions. The formula for a nitrate ion is . The charge on each of the nitrate ion is -1. The charge on the two ions should balance. As a result, each ion in lead nitrate would pair up with two ions. The formula for lead nitrate will be . Each formula unit of lead nitrate will contain one ion and two ions.

The "III" in the name "chromium (III) nitrate" is a Roman Numeral. It indicates that the oxidation state of Cr in chromium (III) nitrate is +3. The Cr in that compound will exist as . Similarly, each will pair up with three ions. The formula for chromium (III) nitrate will be . Each formula unit of chromium (III) nitrate will contain one ion and three ions.

0.85 moles formula units of lead nitrate will contain 0.85 × 2 = 1.7 moles of ions. Those nitrate ions will end up in 1.7 / 3 = 0.57 moles formula units of chromium (III) nitrate. As a result, the reaction will produce 0.57 moles formula units of chromium (III) nitrate.

HIGH SCHOOL

A solution contains 0.159 mol K3PO4 and 0.941 molH2O. Calculate the vapor pressure of the solution at 55 ∘C. The vapor pressure of pure water at 55 ∘C is 118.1 torr. (Assume that the solute completely dissociates.)

Answers

Answer:

49.8 Torr will be the vapor pressure of the solution

Explanation:

Vapor pressure lowerig is the colligative property that must be applied to solve this. The formula is: ΔP = P° . Xm . i

where ΔP = P° (vapor pressure of pure solvent) - Vapor pressure of solution (P')

Xm, the mole fraction of solute (moles of solute / total moles)

i = Van't Hoff factor (numbers of ions dissolved in the solution)

The solute, potassium phosphate dissociates like this:

K₃PO₄  →  3K⁺  +  PO₄³⁻  so we have 3 moles of cation K⁺ and 1 mol of phosphate. Therefore, we have 4 moles of ions, is we assume that the solute completely dissociates → i = 4

Let's find out the mole fraction for solute (Xm)

Xm = mol of solute / Total moles

where total moles = mole of solute + moles of solvent

0.159 mol + 0.941 mol = 1.1 moles

Xm = 0.159 / 1.1 → 0.144

Let's replace the data in the formula

P° - P'= P° . Xm . i

118.1 Torr - P' = 118.1 Torr . 0.144 . 4

P' = - (118.1 Torr . 0.144 . 4 - 118.1 Torr)

Vapor pressure for solution is : 49.8 Torr

MIDDLE SCHOOL

People can’t drink ocean water. However, in very dry areas near the ocean, people purify ocean water. They must use this process to obtain safe drinking water. The main substance that’s dissolved in ocean water is salt, and it must be removed. Salt water is classified as a mixture. This kind of mixture can’t be separated by . Instead, more expensive methods must be used. The first ocean water purification method requires heating. This method, , is based on the fact that water boils at a lower temperature than salt. The second method does not require heating. This method, , has become more common in recent years. Some parts of the world have contaminated water that causes diseases. Contaminated water has microorganisms, and forms a mixture. This kind of mixture can be separated by

Answers

While preparing tea, a filter or a sieve is used to separate tea leaves from the water. Through the sieve pores, only water will pass. The liquid which has obtained after filtration is called filtrate.

What is filtration?

Filtration can be defined as the mechanical or physical process used for the separation of one substance from another, such as solid, liquid or gasses, with the aid of an interposing medium.

In the very humid area near the pond, river, seas ocean, people purify the water. They must use this process to obtain safe drinking water. The substance that is dissolved in ocean water is salt, and it must be removed. This kind of mixture can’t be separated by filtration.

Instead, more expensive methods must be used. The first ocean water purification method requires more heating. This method, distillation, is based on the fact that water boils at a lower temperature than salt. The second method does not require heating.

This method, reverse osmosis, has become more common in recent years. Some parts of the world have contaminated water that causes diseases. Contaminated water has microorganisms, and forms a mixture.

Therefore, the mixture can be separated by filtration.

To know more about filtration, refer to below link:

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#SPJ2

Answer:

People can’t drink ocean water. However, in very dry areas near the ocean, people purify ocean water. They must use this process to obtain safe drinking water. The main substance that’s dissolved in ocean water is salt, and it must be removed. Salt water is classified as a HOMOGENEOUS mixture. This kind of mixture can’t be separated by FILTRATION . Instead, more expensive methods must be used. The first ocean water purification method requires heating. This method, DISTILLATION , is based on the fact that water boils at a lower temperature than salt. The second method does not require heating. This method, REVERSE OSMOSIS , has become more common in recent years. Some parts of the world have contaminated water that causes diseases. Contaminated water has microorganisms, and forms a HETEROGENEOUS mixture. This kind of mixture can be separated by FILTRATION

Explanation:

MIDDLE SCHOOL

What is an oxidizing agent? O
A. A substance that oxidizes another substance
O
B. A substance that is oxidized in a reaction
O
C. A substance that reduces another substance
O
D. The product of an oxidation reaction
SUBN

Answers

Answer:

A.) A substance that oxidizes another substance

Explanation:

An oxidizing agent always oxidize another substance by either accept electron, removing electronegative elements or adding electropositive elements to the substance.

MIDDLE SCHOOL

A Compound is found to contain 37.47% carbon , 12.61% hydrogen , and 49.92 % oxygen by mass. What is the empirical formula for this compound ?

Answers

Answer:

CH₄O

Explanation:

Given parameters:

Mass percentage of:

          Carbon = 37.47%

           Hydrogen = 12.61%

            Oxygen = 49.92%

Unknown:

Empirical formula of the compound = ?

Solution:

The empirical formula of a compound is the simplest ratio by which the atoms in a compound combines.

The actual formula of a compound is called the molecular formula.

To solve for the empirical formula, we follow this process;

 

Elements                   Carbon                        Hydrogen           Oxygen

Mass

Percentage                 37.47                             12.61                   49.92

Molar

mass                               12                                   1                           16

Number

of moles                      37.47/12                        12.61/1                 49.92/16

                                         3.12                             12.61                   3.12

Divide by

the smallest                 3.12/3.12                       12.61/3.12             3.12/3.12

                                          1                                      4                           1

Empirical formula = CH₄O

MIDDLE SCHOOL

Which temperature scale has no negative temperatures? A) Celsius B) Fahrenheit C) Joule D) Kelvin

Answers

Kelvin scale because it has its zero point at the lowest possible measurable temperature:absolute zero.
The Kelvin scale has no negatives on it.

Zero Kelvin is 'Absolute Zero', and nothing can get colder than that.
HIGH SCHOOL

CORRECT ANSWER ONLY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! NO EXCEPITIONS!!!!!!!!!!!!!OR AT LEAST EDUCATED GUESSES!!!!!!!!!!!!!!! AND WHY IS THEIR NO TAB FOR SCIENCE!!!!!!! I'LL JUST PUT IT UNDER CHEMISTRY!!!!!! Which of Newton's laws is related to the condition "A force is required to cause motion to deviate from a straight line"?
First Law
Second Law
Third Law

Answers

Hello there!

Which of Newton's laws is related to the condition "A force is required to cause motion to deviate from a straight line"?  

This would be known as Newton's (first law) of motion.

In other words of saying this, an object that stays in rest, stays in rest, but as for a object that stays in motion, stays in motion, until something were to stop it or go against it.

I hope this helps you!
It would be Newton's First Law. Its basically "An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force."
MIDDLE SCHOOL

Elements in the same group (family) appeared to have the same what?    A) valence. B) melting point. C) isotopic ratio. D) number of neutrons.

Answers

I think it's D- Number of neutrons
MIDDLE SCHOOL

What volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol)?

Answers

We have that for the Question "What volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol)?" it can be said that The volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol) is

V=0.862L

From the question we are told

What volume of 0.20MNaCl (aq) contains 10.0g of NaCl (molar mass 58g/mol)?

Generally the equation for the  morality  is mathematically given as

V=0.862L

Therefore

The volume of 0.20MNaCl(aq) contains 10.0g of NaCl (molar mass 58g/mol) is

V=0.862L

For more information on this visit

brainly.com/question/23379286

The volume of 0.20M NaCl solution containing 10g of NaCl will be 34.48 ml.

Molarity can be defined as the moles of solute in a liter of solution.

The 10 g of NaCl will be:

moles of NaCl =

Moles of NaCl = 0.172 moles

Volume of NaCl solution = 0.172 0.20

Volume of NaCl solution = 0.0344 liters

1 liter = 1000 ml

0.0344 liters = 0.0344 1000 ml

Volume of 0.20M NaCl solution containing 10g of NaCl will be 34.48 ml.

For more information, refer to the link:

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Random Questions
1Carina loved running, and she loved winning too. She was the captain and star athlete of her track and field team. Although Carina wasn’t an excellent runner when she first joined the team two years earlier, she practiced all the time and soon began to win almost every race in which she competed. Carina was doing so well that she thought she might become the winningest track and field athlete in her school’s history! 2One afternoon at track practice, Coach Winder nabbed everyone’s attention to introduce a new athlete. “This is Roberto," he said. "He just transferred to our school from Greensboro Middle School. Please welcome Roberto to the team!” 3The members of the team clapped and jostled each other as they tried to shake Roberto’s hand. As the team captain, Carina shook Roberto’s hand first. She introduced herself and told Roberto that she was excited to have another team member. Roberto told Carina that he had been reluctant about joining the team, but Carina assured him that he would have a marvelous time. 4The next day, the members of the track team stretched before running some sprints. Carina told Roberto that he could race with her. “Don’t worry,” she said. “I’ll go easy on you because it’s your first practice.” 5Carina and Roberto lined up at the starting blocks. When they heard the CRACK of the starting pistol, Roberto and Carina started. After a short distance, Carina realized that Roberto was no longer beside her. She turned to see how far behind he had fallen, but to her amazement, Roberto was not behind her. She looked up and saw Roberto surging ahead. His feet moved as fast as lightning! When Carina realized that she was about to lose, she ran as vigorously as she could; however, it wasn’t enough. Roberto triumphed. Carina seemed almost paralyzed with shock, but she managed to smile and congratulate him. 6Over the next few weeks, Roberto became a phenomenon on the track. No matter how hard Carina trained, she could never beat Roberto. 7One evening after a track meet, Carina was desolate. Roberto had won first place, and Carina had come in third! She considered hanging up her running shoes and quitting the team. Just as she was about to call Coach Winder, her father entered the living room. Carina explained her situation to him. 8“If winning is so important to you that you can’t merely have fun being a member of the team,” said Carina’s father, “then I guess quitting is your only option. But, before you make your decision, think about why you originally joined the team.” 9The next day, Carina walked into Coach Winder’s office and handed him a slip of paper. Coach Winder’s eyes widened as he read it. Then, he closed the note and shook his head approvingly. 11“That’s right,” Carina said with a smile, “I’d like Roberto to serve as co-captain of the team.” Question: Identify the narrator's point of view and analyze how it shapes the story. In other words, how does the choice of narrator affect the story? Provide text examples to support your response. Consider how much the narrator knows, the physical extent of the information available, and the attitude of the narrator towards the information (plot). Answer: