Answer: The enthalpy of combustion, per mole, of butane is -2657.4 kJ
Explanation:
The balanced chemical reaction is,
[tex]2C_4H_{10}(g)+13O_2(g)\rightarrow 8CO_2(g)+10H_2O(g)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=[n\times H_f_{products}]-[n\times H_f_{reactants}][/tex]
Putting the values we get :
[tex]\Delta H=[8\times H_f_{CO_2}+10\times H_f_{H_2O}]-[2\times H_f_{C_4H_{10}+13\times H_f_{O_2}}][/tex]
[tex]\Delta H=[(8\times -393.5)+(10\times -241.82)]-[(2\times -125.7)+(13\times 0)][/tex]
[tex]\Delta H=-5314.8kJ[/tex]
2 moles of butane releases heat = 5314.8 kJ
1 mole of butane release heat = [tex]\frac{5314.8}{2}\times 1=2657.4kJ[/tex]
Thus enthalpy of combustion per mole of butane is -2657.4 kJ
Which of the following best describes the difference between a mixture and a pure substance? A. A mixture has different properties throughout; a pure substance has the same properties throughout. B. A mixture is made up of more than one type of atom; a pure substance is made up of only one type of atom. C. A mixture is made up of only one type of atom; a pure substance is made up of more than one type of atom. D. A mixture has the same properties throughout; a pure substance has the different properties throughout.
Answer:d
Explanation:
Answer:
A mixture has different properties throughout; a pure substance has the same properties throughout.
Explanation:
What is the molar mass of Pb(ClO )4 ?
Answer:
605.0024
The molar mass and molecular weight of Pb(ClO4)4 is 605.0024.
Explanation:
Can somebody give me some backup for this question?
1. Convert 1.5 moles to molecules 2. Convert 1.204x10^24 molecules to moles 3. Convert 1.5x10^20 molecules to moles 4.Convert 0.35 moles to molecules 5. Convert 15 moles H2O to atoms 6.Convert 0.75 moles CaSO4 to atoms
Answer:
Explanation:
1.5 moles to molecules
1 mole = 6.02 x 10²³ molecules
1.5 moles = 6.02 x 1.5 x 10²³ molecules
= 9.03 x 10²³ molecules
2 )
Convert 1.204x10²⁴ molecules to moles
6.02 x 10²³ molecules = 1 mole
1.204x10²⁴ molecules = 1.204x10²⁴ / 6.02 x 10²³ moles
= 2 moles
3 ) Convert 1.5x10^20 molecules to moles
6.02 x 10²³ molecules = 1 mole
1.5x10²⁰ molecules = 1.5x10²⁰ / 6.02 x 10²³ moles
= .25 x 10⁻³ moles
= 2.5 x 10⁻⁴ moles .
4 )
Convert 0.35 moles to molecules
1 moles = 6.02 x 10²³ molecules
.35 mole = 6.02 x .35 x 10²³ molecules
= 2.1 x 10²³ molecules.
5 )
Convert 15 moles H₂O to atoms
1 moles = 6.02 x 10²³ molecules
15 moles = 15 x 6.02 x 10²³ molecules
= 90.3 x 10²³ molecules of water
1 molecule of water has 3 atoms in total
90.3 x 10²³ molecules of water = 90.3 x 3 x 10²³ atoms
= 270.9 x 10²³ atoms .
6 )
0.75 moles CaSO₄ to atoms
1 moles = 6.02 x 10²³ molecules
.75 moles = .75 x 6.02 x 10²³ molecules of CaSO₄
= 4.515 x 10²³ molecules of CaSO₄
1 molecule of CaSO₄ = 6 atoms
4.515 x 10²³ molecules of CaSO₄ = 6 x 4.515 x 10²³ atoms
= 27.09 x 10²³ atoms .
How many atoms are there in 0.655 moles of C6H14?
Answer: 3.94 x 10^23 molecules
Explanation: hope this helps!
Matching
Match each definition with the correct term.
Definitions
_____ 1. device for measuring temperature
_____ 2. total kinetic energy of particles of matter
_____ 3. amount of energy needed to raise the temperature of 1 gram of a substance by 1 °C
_____ 4. average kinetic energy of particles of matter
_____ 5. scale for measuring temperature
From the CK-12 Physical Science For Middle School Workbook
_____ 6. transfer of thermal energy between objects with different temperatures
_____ 7. measure that affects the thermal energy of matter but not its temperature
Terms
thermal energy
heat
temperature
thermometer
mass
Celsius
specific heat
Answer:
1. thermometer
2. thermal energy
3. specific heat
4. temperature
5. Celsius
6. heat
7. mass
what does this graph represent?
A. speed
B. velocity
C. acceleration
D. momentum?
HELP ME PLEASE I NEED THE ANDEER NOW
Thermal energy would naturally flow between objects at which temperatures?
O A. from 5°C to -5°C
OB. from 15°C to 15°C
OC. from 35°C to 45°C
OD. from -15°C to 15°C
Answer:
i think the answer is letter C. From 35°c to 45°c
Explanation:
sorry if it is wrong
Complete the Replication and Transcription of the following DNA Sequence:
GGAGTTACAGTTAGTA
Replication (DNA to DNA):
Transcription (DNA to RNA):
Answer:
CCUCAAUGUCAAUCAU or you could try CCTCAACGTCAATCAT i could be wrong so sorry im not the best
Answer:
Replicated DNA: CCT-CAA-TGT-CAA-TCA-T
Transcription sequence (mRNA): CCU-CAA-UGU-CAA-UCA-U
Explanation:
5.08 moles of an ideal gas are contained in a 3000-mL container at a temperature of 25 °C. What pressure does the gas exert, in mm Hg, on the container?
Answer:
eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeiiiiiieeeeeemmmmmmmmiemeeeeeiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiimiiiimmmmmmmmmmmmmmmmmmmiimmiimiiiiiiiimiiiiiimmii
Explanation:
How do scientists know a reaction in dynamic equilibrium hasn't just stopped?
Answer:
any reaction will be in dynamic equilibrium if it's reversible and the rates of the forward and reverse reactions are equal.
Explanation:
say that you prepare a solution that is saturated with an aqueous solution of NaCl
Would the primary consumers, secondary consumers, or tertiary consumers have more total mass?
Answer:
primary
Explanation:
What type of reaction is the following:
2 Na + Cl2 -> 2 NaCl
decomposition
double replacement
single replacement
synthesis
Answer:
Synthesis :)
Explanation:
553.5 mL ?:cm^3
how do i get my answer? and what is the answer?
Answer:
553.5 cm3
Reason:
1 mL = 1 cm3
There are two suspects in a shooting investigation. Bullets are recovered from the crime scene. Both suspects own guns, and these guns have been seized by the police. How will the investigators check to see if one of these guns fired the found bullets?
Answer:
They can check if one of the bullets is gone if the gun was fully loaded or they can see if there is any particles of gun powder on the gun. I may be wrong.
1. A student predicted the reaction between hydrogen and oxygen gas would yield 125
mL of water. However, after measuring the water formed in the reaction, the
student determined that only 110mL of water was actually formed. What is the
percent yield of this reaction?
Answer:
88%
Explanation:
percent yield is the actual yield divided by the theoretical (predicted) yield, then multiplied by 100 to get a percentage.
110/125 = 0.88
0.88 x 100 = 88%
8. What is the [H+] of a solution with a pH of 4.78
Answer:
7.01 is the answer of the [H+] of a solution with a pH of 4.78
If the volume is 500 mL, the mass of air is 60g (molar mass of air= 29g/mol), and the temperature is 0 C, what is the pressure inside the bottle?
Answer:
The pressure inside the bottle is 92.678 atm.
Explanation:
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
P= ?V= 500 mL= 0.500 Ln= 60 g* [tex]\frac{1 mole}{29 g}[/tex] = 2.07 molesR= 0.082 [tex]\frac{atm*L}{mol*K}[/tex]T= 0 C= 273 KReplacing:
P* 0.500 L= 2.07 moles* 0.082 [tex]\frac{atm*L}{mol*K}[/tex] * 273 K
Solving:
[tex]P=\frac{2.07 moles* 0.082 \frac{atm*L}{mol*K} * 273 K}{0.500 L}[/tex]
P= 92.678 atm
The pressure inside the bottle is 92.678 atm.
SOMEONE SMART HELP PLS!!
HELPPPPPPPPPPPPPP
If 300 rats are each given an LD50 dose of 3 000mg, what do you expect to happen
Answer:
LD50 is the amount of a material, given all at once, which causes the death of 50% ... LD100 Lethal dose for 100% of the animal test population ... Researchers can do the test with any animal species but they use rats or mice ... quoted as parts per million (ppm) or milligrams per cubic metre
Explanation: hope this helps :)
how many grams will be produced??
Explanation:
b is correct. 30.6 g H2O is produced.
Match the items to use the analogy of time to the vocabulary of chemistry.
Answer:
1 year- 1 mole
time in general- amount of matter
1 second- 1 atom/ particle
Answer:
1 Year => 1 Mole
Time in General => Amount of Matter
1 Second => 1 Atom/Particle
Explanation:
These pairs make the most sense.
Hope it helps!!!
The Kₐ of carbonic acid is 4.3 x10⁻⁷ . H₂CO₃ ⇄ H⁺ + HCO₃ ⁻ This means that H₂CO₃ is a
A) Good hydrogen-ion acceptor.
B) Poor hydrogen-ion acceptor.
C) Good hydrogen-ion donor.
D) Poor hydrogen-ion donor.
Answer:
A good hydrogen ion acceptor
PLS PLS HELP FAST When a pure substance is heated from 35.0°C to 50.0°C, it absorbs 5,200 J of energy. (50 g) What is the specific heat of the substance? You must show your work for full credit.
Answer:
6.93 J/g C
Explanation:
5200=50 g (15 C)x
5200=750x
Also I just took the test
If a chemical reaction occurs, the properties of substances before and after the substances interact must be
Answer:
different
Explanation:
A chemical reaction may be defined as the process or method by which a substance undergo a change in their structure chemically when reacting with some other substance and acquiring the property of both or sometimes forms a new substance. It leads to the chemical transformation of the chemical substance to some another substance.
The properties of the new substance formed is different form the parent substance before the reaction.
Thus, when chemical reaction occurs, the properties of the substances before the reaction and after the reaction takes place is different.
What is the mass of 8.98 x 10^24 particles of CaCl2?
Answer:
1656.12grams
Explanation:
To calculate the mass of a substance in a particle, we need to calculate the number of moles (n).
n = nA × 6.02 × 10^23
nA = 8.98 x 10^24 particles
number of moles = 8.98 x 10^24 ÷ 6.02 × 10^23
n = 8.98/6.02 × 10^ (24 - 23)
n = 1.492 × 10^1
n = 14.92moles of CaCl2
Molar Mass of CaCl2 where Ca = 40g/mol, Cl = 35.5g/mol
CaCl2 = 40 + 35.5(2)
= 40 + 71
= 111g/mol
Using mole = mass/molar mass
mass = molar mass × mole
mass = 111 × 14.92
mass = 1656.12grams.
How many moles are in 45.5 g of P2O5 ?
Answer:
0.327214 mol
Explanation:
45.5/278.106=0.163607
Then, 0.163607x2= 0.327214
1. Which group of elements does not get an electronegativity value
because they do not form compounds? *
Alkali Metals
Alkaline Earth Metals
Boron Group
Carbon Group
Nitrogen Group
Oxygen Group
Answer:
noble gases from what i learnt
Which of these layers is found directly above the Earth's core?
Group of answer choices
Outer core
Mantle
Inner core
Crust
Answer: Mantle
Explanation:
there are 3 layers of the earth- core, mantle and crust. The layer found directly above the earth's core is the mantle.
Answer:
The answer depends on what you are taking about: the outer core or the inner core?
Answer: Mantle
Explanation:
If you find a picture of the Earth's layers, you can see that the inner core is the bottommost layer. However, if you combine the Inner Core and Outer Core, that could be determined as the Earth's core.
I would chose the Mantle because if the two cores are combined, the layer directly above them is the Mantle.