Answer:
-1396 kJ
Explanation:
Let's consider the following balanced equation.
4 NH₃(g) + 7 O₂(g) ⇒ 4 NO₂(g) + 6 H₂O(l)
We can calculate the standard change in enthalpy for the reaction (ΔHr) using the following expression.
ΔHr = ∑ np × ΔHf(p) - ∑ nr × ΔHf(r)
where,
n: molesΔHf: standard enthalpies of formationp: productsr: reactantsΔHr = 4 mol × ΔHf(NO₂(g)) + 6 mol × ΔHf(H₂O(l)) - 4 mol × ΔHf(NH₃(g)) - 7 mol × ΔHf(O₂(g))
ΔHr = 4 mol × (34 kJ/mol) + 6 mol × (-286 kJ7mol) - 4 mol × (-46 kJ/mol) - 7 mol × (0 kJ/mol) = -1396 kJ
How many joules would be released when 256 grams of zinc at 96 c were cooled to 28 c
Answer:
–6562.816 J
Explanation:
From the question given above, the following data were obtained:
Msss (M) = 256 g
Initial temperature (T₁) = 96 °C
Final temperature (T₂) = 28 °C
Heat (Q) released =?
Next, we shall determine the change in temperature. This can be obtained as follow:
Initial temperature (T₁) = 96 °C
Final temperature (T₂) = 28 °C
Change in temperature (ΔT) =?
ΔT = T₂ – T₁
ΔT = 28 – 96
ΔT = –68 °C
Finally, we shall determine the heat released. This can be obtained as follow:
Msss (M) = 256 g
Change in temperature (ΔT) = –68 °C
Specific heat capacity (C) of Zn = 0.377 J/gºC
Heat (Q) released =?
Q = MCΔT
Q = 256 × 0.377 × –68
Q = –6562.816 J
Thus, –6562.816 J of heat energy is released.
Balance the following Equation (do not leave any empty blanks, you must enter 1 if the value is 1):
___ Na2S + ___ HCl --> ___ NaCl + ___ H2S
(Refer to image)
What type of reaction is it?
(Question one is a _______ type of reaction.)
Answer: this looks hard
Explanation:
Answer:
1 Na2S + 2 HCl ===> 2 NaCl + 1 H2S
In these reactions, two compounds exchange ions to form two new compounds.
Explanation:
--- Na2S + ---- HCl ===> ---- NaCl + ---- H2S
Na = 2 Na = 1 * 2 = 2
S = 1 S = 1
H = 1 * 2 = 2 H = 2
Cl = 1 * 2 = 2 Cl = 1 * 2 = Cl
In these reactions, two compounds exchange ions to form two new compounds.
REACTION TYPE:
DOUBLE DISPLACEMENT REACTION/DOUBLE REPLACEMENT
I hope that helps, have a wonderful day!!!!
What is the molecular weight of MgCl2
The molecular weight of MgCl₂ is 94 g/mol.
What is molecular weight?This refers to the total mass of a compound. It is equivalent to the sum of the individual atomic masses of each atom in the molecule.
Steps to determine the molecular formula of the molecule.
Determine the atomic mass of each element in the molecule.Multiply each element's atomic mass by the number of atoms of that element in the molecule. This number is represented by the subscript next to the element symbol in the molecular formula.Add these values together for each different atom in the molecule.The total will be the molecular mass of the compound.Atomic number of Cl =17
Atomic number of Mg = 12
Mass number of Cl = 35
Mass number of Mg = 24
Calculating the molecular weight of MgCl₂
MgCl₂
=(12* 2) + (35*2)
= 24 + 70
= 94 g/mol.
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The entropy change for a real, irreversible process is equal to:______.
a. the entropy change for a theoretical reversible process with the same initial and final states.
b. equal to the entropy change for the same process performed reversibly ONLY if the process can be reversed at all.
c. zero.
d. impossible to tell.
Answer:
The entropy change for a real, irreversible process is equal to zero.
The correct option is 'c'.
Explanation:
Lets look around all the given options -:
(a) the entropy change for a theoretical reversible process with the same initial and final states , since the entropy change is equal and opposite in reversible process , thus this option in not correct.
(b) equal to the entropy change for the same process performed reversibly ONLY if the process can be reversed at all. Since , the change is same as well as opposite too . Therefore , this statement is also not true .
(c) zero. This option is true because We generate more entropy in an irreversible process. Because no heat moves into or out of the surroundings during the procedure, the entropy change of the surroundings is zero.
(d) impossible to tell. This option is invalid , thus incorrect .
Hence , the correct option is 'c' that is zero.
Answer: the entropy change for a theoretical reversible process with the same initial and final states
Look at the diagram. De both lemas and humans have the traits listed at point D? Explain your reasoning
Answer:
WHAT DIAGRAM THX FOR POINTS THO
Explanation:
All radioactive sources have a half-life.
Which statement about the half-life of a source is correct?
A. It is half the time it takes for an atom to decay
B. It is half the time for the radioactive source to become safe
C. It is the time it takes the actity of the source to decrease by half
D. It is half the time it takes the activity of the source to decrease to zero
Answer:
The answer is C
Explanation:
Duh its the name HALF LIFE!!
just a way to remember
The statement which is true about the half-life of a source is (D) It is half the time it takes the activity of the source to decrease to zero. Hence the correct option is (D)
What is Half Life Period of a source ?Half-life is the length of time it takes for a radioactive element to decay to half of its initial value.
This suggests that a source's activity has a half-life when it takes time for it to decrease to half its initial value.
It is the amount of time needed for half of the atomic nuclei in a radioactive sample to spontaneously decay, which releases energy and particles into other nuclear species. Alternatively, it is the amount of time needed for the radioactive sample to disintegrate at a rate of one per second.
Therefore, The statement which is true about the half-life of a source is (D) It is half the time it takes the activity of the source to decrease to zero. Hence the correct option is (D)
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Which of the following is the balanced equation
for the decomposition of hydrogen peroxide
(H2O2) into water and oxygen gas?
A H2O2 - 2H + 20
В. НО
H202 -- H2O + O2
a
2H202
H2O + 202
D 2H202 - 2H2O + O2
Answer:
D
Explanation:
2H202 = 2H2O + O2
Why atoms form compounds
Answer:
Because the atoms are trying to reach the most stable ( lowest energy ) state they can.
CaCO3 (s) + 176 KJ à CaO (s) + CO (g)
A. 176 KJ are released in an endothermic reaction.
B. 176 KJ are released in an exothermic reaction
C. 176 KJ are absorbed in an exothermic reaction.
D. 176 KJ are absorbed in an endothermic reaction.
Answer:
its d
Explanation:
How can heat change matter from a solid to a liquid to a gas?
Help ima mark Brainlyest!!
When applying heat the solid will eventually reach its melting point. Its then that the solid will slowly start to turn into a liquid due to the heat transfer. The process will only continue with even more heat piling up causing it to evaporate and become a gas.
Heat transfer comes in different ways depending on the solid:
either-
| | |
conduction
convection
or
radiation
- - - - -
this is all I know for now.
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Lucky me! We actually learned this in class today
I hope I helped in some way! :)
A chemist has one solution that is 30.% acid and another solution that is 18% acid. How much of each solution should be used to get 300. L of a solution that is 21% acid?
a. 23 L of the 30.% solution and 277 L of the 18% solution
b. 75 L of the 30.% solution and 225 L of the 18% solution
c. 131 L of the 30.% solution and 169 L of the 18% solution
d. 138 L of the 30.% solution and 162 L of the 18% solution
e. 244 L of the 30.% solution and 56 L of the 18% solution
There is a golden rule of solubility, non polar solute dissolve in non polar solvent and polar solute dissolve in polar solvent. Therefore, the correct option is option B.
What is solution?
Solution is a homogeneous mixture of two or more than two substances. A solution is a homogeneous mixture of solute and solvent molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution.
There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution. The nature of solvent tells about whether the solvent is in liquid, solid or gas form.
Let amount of 30% to mix, be X
Then amount of 18% to mix = 300 - X
0.3X + 0.18(300 - X) = 0.21(300)
0.3X+ 0.18(300) - 0.18X= 0.21(300)
0.3X - 0.18X =0 .21(300) -0 .18(300)
0.12X =0 .03(300)
X=75L
Therefore, the correct option is option B.
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The table shows the chemical formulas for four substances. Substance Chemical Formula 1 C2H60 CH 2. "8" 18 ليبيا CH,CH_Br C.H.. 4. Which substances have the same number of carbon atoms? A Substances 1 and 2 B Substances 2, 3, and 4 C Substances 2 and 3 only D Substances 1 and 3
Please I need help with this question.
Answer:
c?
Explanation:
Answer:
b
Explanation:
The EM Spectrum is the __________ range of EM waves in order of __________ frequency and __________ wavelength.
Answer:
entire, increasing, decreasing
Explanation:
The EM Spectrum is the entire range of EM waves in order of increasing frequency and decreasing wavelength.
A sample of N2 has a volume of 616 mL at 68 °C. What will be its volume at -17 °C?
Answer:
462.5ml
Explanation:
Using Charle's law equation;
V1/T1 = V2/T2
Where;
V1 = initial volume (ml)
V2 = final volume (ml)
T1 = initial temperature (K)
T2 = final temperature (K)
Based on the information provided in this question;
V1 = 616ml = 616/1000 = 0.616L
V2 = ?
T1 = 68°C = 68 + 273 = 341K
T2 = 17 °C = -17 + 273 = 256K
V1/T1 = V2/T2
0.616/341 = V2/256
Cross multiply
341 × V2 = 256 × 0.616
341V2 = 157.69
V2 = 157.69/341
V2 = 0.4625 L or 462.5ml
The Sun is located _____.
in the central core of the Milky Way galaxy
in the bar of the Milky Way
in an arm about 25% of the distance from the center of the Milky Way to its outer edge
in an arm about 75% of the distance from the center of the Milky Way to its outer edge
Answer:
I believe the answer is going to be A. in the central core of the Milky Way galaxy.
Explanation: lol sorry I put it in the question box instead of answering it, hope this helps!
How many grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate?
Answer: There is 842.54 grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate.
Explanation:
Chemical equation depicting reaction between sodium phosphate and aluminum carbonate is as follows.
[tex]Al_{2}(CO_{3})_{3} + 2Na_{3}PO_{4} \rightarrow 2AlPO_{4} + 3Na_{2}CO_{3}[/tex]
As this equation contains same number of atoms on both reactant and product side. So, this equation is a balanced equation.
According to the equation, 2 moles of sodium phosphate is giving 3 moles of sodium carbonate.
Therefore, sodium carbonate formed by 5.3 moles of sodium phosphate is as follows.
[tex]\frac{3}{2} \times 5.3 mol\\= 7.95 mol[/tex]
As number of moles is the mass of substance divided by its molar mass. So, mass of sodium carbonate ( molar mass = 105.98 g/mol) is as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\7.95 mol = \frac{mass}{105.98 g/mol}\\mass = 842.54 g[/tex]
Thus, we can conclude that there is 842.54 grams of sodium carbonate are produced when 5.3 moles of sodium phosphate reacts with aluminum carbonate.
Because the mass of the flask with water exceeds the amount that can be weighed on the digital balances, the triple-beam-balance is used, which only weighs to the nearest 0.01 g. Why doesn't using this balance affect the number of significant digits to which the experimental molecular weight of carbon dioxide can be reported
Answer:
The Less accuracy of this method is the reason for this balance affecting the number of significant digits to which the experimental molecular weight of carbon dioxide can be reported.
Explanation:
As we know the triple-beam-balance method is a less accurate method of measurement of mass.
An accurate molecular weight is not required in this case. So, this method is being used because much accuracy is not required.
That is why this balance affects the number of significant digits to which the experimental molecular weight of carbon dioxide can be reported.
what is the energy of a photon of yellow light with a frequency of 5.2 x 10¹⁴ Hz?
Answer:
3.4x10⁻¹⁹J is the energy of the photon
Explanation:
To find the energy of a photon from its frequency we must use the equation:
E = hf
Where E is the energy of the photon in J, our incognite
h is Planck's constant = 6.6262x10⁻³⁴Js
And f is the frequency = 5.2x10¹⁴Hz = 5.2x10¹⁴s⁻¹
Replacing:
E = 6.6262x10⁻³⁴Js*5.2x10¹⁴s⁻¹
E = 3.4x10⁻¹⁹J is the energy of the photon
In today's experiment, Solutions A and B are prepared as follows.
Solution A: Solution B:
2.0 mL of 3.00 x 10-4 M bromcresol green 2.0 mL of 3.00 x 10-4 M bromcresol green
5.0 mL of 1.60 M acetic acid (HAc) 2.0 mL of 0.160 M sodium acetate (NaAc)
2.0 mL of 0.200 M KCl diluted to a total volume of 50 mL
diluted to a total volume of 50 mL
What is the molarity of HAc in Solution A?
A. 6.4x 10-3
B. 3.20 x 10-4
C. 8.0 x 10-3
D. 0.160
E. 1.60
Answer:
D. 0.160
Explanation:
The solution A is obtained adding 2.0mL of a solution of bromocresol green, 5.0mL of 1.60M HAc and 2.0mL of a solution of KCl. The solution is diluted to 50mL
That means the HAc is diluted from 5.0mL to 50.0mL, that is:
50.0mL / 5.0mL = 10 times.
And the final concentration of HAc must be:
1.60M / 10 times =
0.160M
Right answer is:
D. 0.1601. What is the process in which two daughter cells form called?
2. What are the five phases of mitosis?
3. What is the longest stage of mitosis?
4. What occurs during prophase?
5. What occurs during metaphase?
6. What occurs during anaphase?
7. What occurs during telophase?
8. Meiosis divides the cell into how many daughter cells?
9. Is Mitosis or Meiosis used in sexual reproduction?
10. What is the difference between asexual and sexual reproduction?
Answer:
1. Mitosis is a process of nuclear division in eukaryotic cells that occurs when a parent cell divides to produce two identical daughter cells. During cell division, mitosis refers specifically to the separation of the duplicated genetic material carried in the nucleus.
2. Today, mitosis is understood to involve five phases, based on the physical state of the chromosomes and spindle. These phases are prophase, prometaphase, metaphase, anaphase, and telophase.
3. Prophase. The first and longest phase of mitosis is prophase. During prophase, chromatin condenses into chromosomes, and the nuclear envelope (the membrane surrounding the nucleus) breaks down. In animal cells, the centrioles near the nucleus begin to separate and move to opposite poles of the cell.
4. During prophase, the complex of DNA and proteins contained in the nucleus, known as chromatin, condenses. The chromatin coils and becomes increasingly compact, resulting in the formation of visible chromosomes. The sister chromatids are pairs of identical copies of DNA joined at a point called the centromere.
5. During metaphase, the cell's chromosomes align themselves in the middle of the cell through a type of cellular "tug of war." The chromosomes, which have been replicated and remain joined at a central point called the centromere, are called sister chromatids.
6. During anaphase, each pair of chromosomes is separated into two identical, independent chromosomes. The chromosomes are separated by a structure called the mitotic spindle. The separated chromosomes are then pulled by the spindle to opposite poles of the cell.
7. Telophase is the fifth and final phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells. During telophase, a nuclear membrane forms around each set of chromosomes to separate the nuclear DNA from the cytoplasm.
8. Meiosis is a process where a single cell divides twice to produce four cells containing half the original amount of genetic information. These cells are our sex cells sperm in males, eggs in females. During meiosis one cell? divides twice to form four daughter cells.
9. Only sexually reproductive organisms utilize meiosis. Both sexual and asexual organisms go through the process of mitosis. It happens in the cells of the body known as the somatic cells and produces cells related to growth and repair.
10. Asexual reproduction involves one parent and produces offspring that are genetically identical to each other and to the parent. Sexual reproduction involves two parents and produces offspring that are genetically unique.
Explanation:
heart me pls
Remember: all EM waves travel at the same __________. The equation for speed is __________ times the __________. So, for the answer to always be 300,000km/s, as one number goes __________, the other must go __________. All EM waves are __________. The higher the __________, the more __________ in the wave.
All the EM waves travel at the same speed. The equation for speed is frequency (v) times the wavelength (λ). Speed of light equals 300000 km/s. Hence one number goes to 3 × 10⁸ m and other number is 1 s⁻¹.
What is an electromagnetic wave ?Electromagnetic waves are waves moving without a medium through vacuum. They are accompanied with an electric field and magnetic field. The speed of an electromagnetic wave is the product its wavelength and frequency.
c = νλ
Therefore, the given passage can be filled as follows:
All the EM waves travel at the same speed. The equation for speed is frequency (v) times the wavelength (λ). Speed of light equals 300000 km/s. Hence one number goes to 3 × 10⁸ m and other number is 1 s⁻¹.
All EM waves are energetic. The higher the frequency the more energy in the wave.
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If a dog has a mass of 22.9 kg, what is its mass in the following units? Use scientific notation in all of your answers. (a) What is the dog's mass in grams? × 10 g (b) What is the dog's mass in milligrams? × 10 mg (c) What is the dog's mass in micrograms? × 10 μg
Answer:
a) 2.29E4
Explanation: 1kg = 1000g. to get mass in grams multiply 22.9 kg by 1000g then divide by 1 kg to cancel the kg.
b) 2,29E5 g
c) 2.29 E10 μg
the assembly of an RNA strand is called what
Which type of sedimentary rock forms from weathered sediment?
Answer:
Clastic or detrital sedimentary rocks are made from pieces of bedrock, sediment, derived primarily by mechanical weathering.
Explanation:
The moon appears red during a lunar eclipse because red is the __________ wavelength of light in the color spectrum present in sunlight.
longest
shortest
brightest
Answer:
Longest
Explanation:
The visible light spectrum goes from red color to blue color:
The red wavelength of light has the lowest energy in that spectrum, and as such, it is the longest wavelength.Conversely, the blue wavelength of light has the highest energy in that spectrum, and as such, it is the shortest wavelength.As it has the longest wavelength, it can travel further than other wavelengths, which is why the moon appears red during a lunar eclipse.
S + 6 HNO3 → H2SO4 + 6 NO2 + 2 H2O
In the above equation, how many grams of water can be made when 12.1 moles of HNO3 are consumed?
Round your answer to the nearest tenth. If you answer is a whole number like 4, report the answer as 4.0
Use the following molar masses. If you do not use these masses, the computer will mark your answer incorrect.:
Element Molar Mass
Hydrogen 1
Nitrogen 14
Sulfur 32
Oxygen 16
The amount, in grams, of water that can be made when 12.1 moles of [tex]HNO_3[/tex] are consumed would be 72.54 grams.
Stoichiometric problemFrom the balanced equation of the reaction, the mole ratio of [tex]HNO_3[/tex] to water is 3:1.
This means that for every 3 moles of [tex]HNO_3[/tex], 1 mole of water will be produced.
3 mole [tex]HNO_3[/tex] = 1 mole water
12.1 moles HNO3 = 12.1x1/3
= 4.03 mol
Recall that: mass = mole x molar mass
The molar mass of water is 18 g/mol
Thus, the mass of 4.03 mol of water = 4.03 x 18 = 72.54 grams
In other words, going by the equation of the reaction, the mass of water that can be made when 12.1 moles of [tex]HNO_3[/tex] are consumed would be 72.54 grams.
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how does a heavy growth of algae decrease the concentration of oxygen in a lake?
Answer:
Explanation:
iuhyesfdxgrygtvd ctrfdrdt6r76_jjdvrud83447+je8867vbde turn left then go right back then stop done
An analytical chemist is titrating 99.2 mL of a 0.6300 M solution of dimethylamine ((CH3 NH) with a 0.2500 M solution of HNO3. The p K, of dimethylamine is 3.27. Calculate the pH of the base solution after the chemist has added 213.6 mL of the HNO3 solution to it.
Answer:
pH of the base solution after the chemist has added 213.6 mL of the HNO3 solution to it is 9.96
Explanation:
Calculating the moles of dimethylamine
Moles of dimethylamine = molairty * volume in L = 0.63*0.0992 = 0.0625moles
Moles of HNO3 = molarity * volume in L = 0.25*0.2136 = 0.0534 moles
The balanced chemical equation is
(CH3)2NH + HNO3 -------------------> (CH3)2NH2^+ + NO3^-
I 0.0625 0.0534 0
C -0.0534 - 0.0534 0.0534
E 0.0091 0 0.0534
As we know ,
POH = Pkb + log[(CH3)2NH2^+]/[(CH3)2NH]
= 3.27 + log0.0534/0.0091
= 3.27+ 0.768
= 4.038
PH = 14-POH
= 14-4.038 = 9.96
The density of oxygen gas at a certain temperature and pressure is 1.345 g cm-3. How many oxygen atoms are present in 2.0 L of oxygen gas at this same temperature and pressure?
The number of oxygen atoms present in 2.0L of oxygen gas at same temperature and pressure is 5.1 × 10²² atoms.
How to calculate number of atoms?The number of atoms of a substance can be calculated by multiplying the number of moles in the substance by Avogadro's number (6.02 × 10²³).
no of atoms = no of moles × 6.02 × 10²³
According to this question, the density of oxygen gas at a certain temperature and pressure is 1.345 g cm-³. If 2.0 L of oxygen gas is given, the mass of the oxygen gas can be calculated as follows:
mass = 1.345 × 2 = 2.69grams
moles = 2.69g ÷ 32g/mol = 0.084moles
No of atoms = 0.084 mol × 6.02 × 10²³
no of atoms = 5.1 × 10²² atoms
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