1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
podryga [215]
3 years ago
6

When 1.550 g of liquid hexane (C6H14) undergoes combustion in a bomb calorimeter, the temperature rises from 25.87∘C to 38.13∘C.

Find ΔErxn for the reaction in kJ/mol hexane. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.73 kJ/∘C. Express your answer in kilojoules per mole to three significant figures.2. The combustion of toluene has a ΔErxn of –3.91×103 kJ/mol. When 1.55 g of toluene (C7H8) undergoes combustion in a bomb calorimeter, the temperature rises from 23.12∘C to 37.57∘C. Find the heat capacity of the bomb calorimeter. Express the heat capacity in kilojoules per degree Celsius to three significant
Chemistry
1 answer:
AlladinOne [14]3 years ago
3 0

Explanation:

1). The given data is as follows.

       T_{i} = 25.87^{o}C,      T_{f} = 38.13^{o}C

               C = 5.73 kJ/^{o}C

Hence, calculate the change in enthalpy of the reaction as follows.

      \Delta E_{rxn} = -C \times \Delta T

                     = -5.73 \times (38.13 - 25.87)^{o}C

                     = -70.25 KJ

As,  number of moles = \frac{mass}{\text{molar mass}}

                                    = \frac{1.55}{(6 \times 12 + 14 \times 1)}

                                    = 0.018 mol

Therefore, enthalpy of reaction in kJ/mol hexane is as follows.

            \Delta E_{rxn} = \frac{-70.25 KJ}{0.018 mol}

                          = -3.90 \times 10^{3} kJ/mol

Thus, we can conclude that \Delta E_{rxn} for the reaction in kJ/mol hexane is -3.90 \times 10^{3} kJ/mol .

2).  As we know that,

     Number of moles = \frac{mass}{\text{molar mass}}

                                  = \frac{1.55}{(7 \times 12 + 8 \times 1)}

                                   = 0.017 mol

       \Delta E_{rxn} = \E_{rxn} per mol \times \text{number of moles}

                      = -3.91 \times 10^{3} \times 0.017

                      = -65.875 kJ

As,    \Delta E_{rxn} = C \times \Delta T


                    -65.875 kJ = -C \times (37.57 - 23.12)^{o}C

                           C = 4.56 kJ/^{o}C

Hence, heat capacity of the bomb calorimeter is 4.56 kJ/^{o}C.

You might be interested in
What is the half-life of an isotope that decays to 6.25% of its original activity in 18.9 hours?
inessss [21]
Radioactive material obeys 1st order decay kinetics,
For 1st order reaction, we have 
k = \frac{2.303}{t}Xlog \frac{\text{initial conc.}}{\text{final conc.}}
where, k = rate constant of reaction

Given: Initial conc. 100, Final conc. = 6.25, t = 18.9 hours

∴ k = \frac{2.303}{18.9} X log \frac{100}{6.25} = 0.1467 hours^(-1)

Now, for 1st order reactions: half life = \frac{0.693}{k} =  \frac{0.693}{0.1467} = 4.723 hours.


8 0
3 years ago
An isotonic salt solution is 0.90% (w/w) nacl in water. how many grams of nacl are contained in 1.00 kg of such a solution?
Fed [463]

An isotonic salt solution is 0.90% (w/w) nacl in water many grams of nacl are contained in 1.00 kg of such a solution Reconstruction debate that had federalism debate that had been an issue since the 1790s.

Reconstruction failed by most other measures: Radical Republican legislation ultimately failed to isotonic former slaves from white persecution and failed to engender fundamental changes to the social fabric of the South. When President Rutherford B. federalism debate that had been an issue since the 1790s almost mediately . Hayes removed federal troops from isotonic South in 1877, former Confederate officials and slave returned to With the support of a conservative Supreme Court, these newly empowered white southern politicians passed black codes, voter qualifications, and other anti-progressive legislation to reverse the rights that blacks had gained during Radical Reconstruction. The U.S. Supreme Court bolstered this federalism anti-progressive movement federalism  with decisions in the Slaughterhouse Cases, the Civil Rights Cases, and United States v.

Learn more about Reconstruction on:

brainly.com/question/24761999

#SPJ4

3 0
2 years ago
temperature is the transfer of thermal energy from one object to another. Please select the best answer from the choices provide
Hunter-Best [27]

The statement above is FALSE.

Temperature is the degree of coldness or hotness of a body while heat transfer is the transfer of thermal energy from one object to another object. Temperature tells us how cold or hot a body is and it can be measured in Celsius, Kelvin or Fahrenheit. The thermometer is the instrument that is used in the measurement of temperature. Change in temperature is an important indicator that is used in various ways in humans and external systems.  

5 0
3 years ago
When the reactive alkali metal sodium is reacted with poisonous chlorine gas, sodium chloride or table salt is produced. Is mass
PIT_PIT [208]

Answer:

Yes, Mass is conserved.

Explanation:

Every chemical reactions obey the law of conservation of mass. The law of conservation of mass states that in chemical reactions, mass is always constant.

     Equation:

                       2Na + Cl₂  →  2NaCl

From the equation above, one can observe that the reaction started using 2 atoms of Na and it produced 2 atoms of the same element in NaCl. A molecule of Cl produced 2 atoms of Cl in the NaCl

Design a simple experiment to support your answer:

Aim: To demonstrate the law of conservation of mass

   One Na atom weighs 23g

   Two Na atom will weigh 2 x 23 = 46g

1 atom of Cl is 35.5g

1 molecule of Cl containing two atoms of Cl will weigh 2 x 35.5 = 71g

Total mass of reactants = mass of 2Na + 1Cl₂ = (46 + 71)g = 117g

On the product side, Mass of 1 NaCl = 23+ 35.5 = 58.5g

Two moles of NaCl will give 2 x 58.5g = 117g

Since the mass on both side is the same, one can say mass is conserved.

7 0
3 years ago
Remember: When recording genotype, two letters are used, a capital letter (D) for the dominant trait and a lower case (d) letter
masya89 [10]
Tt. i’m not fully sure but dominant traits usually always overpower recessive so i’m pretty sure in order for a recessive trait to show both parents need to give the recessive trait in order for it to show. i mean it’s in the words dominant and recessive
8 0
2 years ago
Read 2 more answers
Other questions:
  • Which of the following is a mixture? steel water oxygen gold
    12·2 answers
  • One cubic meter of an ideal gas at 600 K and 1000 KPa expand to five times its initial volume as follows:
    11·1 answer
  • Density of 2.7 g/ml and volume of 35.6 ml what is the mass
    15·1 answer
  • Predict at least two circumstances that would cause a system in equilibrium to change the concentrations of its reactants and pr
    13·1 answer
  • 1. A substance, A₂B, has the composition by mass of 60% A and 40% B. What is the composition of AB₂ by mass?
    6·1 answer
  • What contains elements with similar properties in the periodic table?
    9·2 answers
  • A student is participating in the school science fair. She wants to investigate household cleaners.
    7·2 answers
  • A chemistry student must write down in her lab notebook the concentration of a solution of sodium hydroxide. The concentration o
    15·2 answers
  • Which of the following would be a clue that a rock is igneous?
    15·2 answers
  • A buildup of charges in an object is called
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!