The combustion of methane, CH4, releases 890.4 kJ/mol. That is, when one mole of methane is burned, 890.4 kJ are given off to the surroundings. This means that the products have 890.4 kJ less than the reactants.
Combustion of one mole or 16 g of methane gas releases 810 kJ of heat energy. Thus, heat released by the combustion of 22.4 g of methane is 1134 kJ.
What is combustion?Combustion of a substance is its reaction with atmospheric oxygen producing carbon dioxide and water. Combustion of hydrocarbons gases takes places easily and can be burned easily for fuels.
The chemical equation of combustion of methane is written below:
[tex]\rm CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O[/tex]
This is an exothermic process and heat is released from the reaction system.
The heat released by the combustion of one mole of methane is 810 kJ.
molar mass of methane = 16 g/mol
no.of moles in 22.4 g = 22.4/16 = 1.4 g
Thus, heat released by 1.4 moles = 1.4 ×810 kJ =1134 kJ.
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please help ASAP
17.8 mL of HNO3 is neutralized in a titration by 24.7 mL of a 0.299 M Sr(OH)2 solution. Calculate the pH of the unknown acid.
Answer:
0.1
Explanation:
We must first put down the equation of the reaction in order to guide our solution of the question.
2HNO3(aq) + Sr(OH)2(aq) -------> Sr(NO3)2(aq) + 2H2O(l)
Now from the question, the following were given;
Concentration of acid CA= ??????
Concentration of base CB= 0.299M
Volume of acid VA= 17.8ml
Volume of base VB= 24.7ml
Number of moles of acid NA= 2
Number of moles of base NB= 1
From;
CAVA/CBVB= NA/NB
CAVANB= CBVBNA
CA= CBVBNA/VANB
SUBSTITUTING VALUES;
CA= 0.299 × 24.7 ×2 / 17.8×1
CA= 0.8298 M
But;
pH= -log[H^+]
[H^+] = 0.8298 M
pH= -log[0.8298 M]
pH= 0.1
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About how long does it take Earth to complete one revolution around the Sun?
1 year
14 days
24 hours
27.3 days
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Submit
Save and Exit
Mark this and retum
rotodo
o
Answer:
A) one year
Explanation:
One complete revolution takes 365.25 days, or one year.
Answer:
1 year
Explanation:
which acids caused the effects seen on the teeth in the study
Answer:
Hcl
Explanation:Idfk :))Bună ziua. La pagina 169 aveți o altă piesă de teatru. Vă rog să o citiți și să răspundeți la întrebările 1,2,4,7,8/ pag. 170.
Sper că vă scrieți toate lecțiile în caiet! Sunt copii care încă nu mi-au trimis nicio temă. Vă rog să vă mobilizați! Când ne întâlnim vă verific caietele. Mult spor!
phosphoric and citric acids
Answer:
Explanation:
The tendency of an object to resist a change.
A. Inertia
B. Friction
C. Law of conservation of motivation
D. Force
Answer:
inertia is the tendency of an object to resist a change
what is the drag force acting on a car with a resultant force of 600N when the engine is pushing it with a force of 11,000N
Answer:
10 400 N
Explanation:
A drag force is an oppositional or limiting force which must be overcome before an object must move wit a force. The lesser the drag force, the higher the probability that an object would move easily.
From the question give, the resultant force of the was is 600 N and force from the engine - 11 000 N.
Drag force = 11 000 - 600
= 10 400 N
The drag force on the car is 10 400 N.
This shows that the car would not move since the drag force (10 400 N) is far greater than the resultant force(600 N).
Which function allows a user to add another item to a list in Python? order() print() sort() append()
Answer:
append()
Explanation:
just took this test, chose this answer, and got it correct
Answer:
d
Explanation:
I guess it is a small world cuz i doing the test on flvs to
hope this helps
The box is at rest on the table.what force is represented by A?
Answer: There is no force if it is at rest
Explanation:
Use the drop-down menus to complete the statement and describe how energy relates to work.
transfers
between objects.
Answer: the first one is work and the second one is energy
Explanation:
Answer:
first :work second:energy
Explanation:
Why do we experience the changing of the seasons on earth
Answer:
Earth's axis and position around the sun.
Explanation:
Earth's tilted axis causes the seasons to change. Throughout the year, different parts of Earth acquire the Sun's most direct rays(Or heat) because of the orbital rotation of Earth. So, when the North Pole tilts toward the Sun, it's summer inside the Northern Hemisphere. And whilst the South Pole tilts towards the Sun, it is winter within the Northern Hemisphere and vise versa.
We experience the changing of the seasons on earth due to earth's changing relationship of the sun.
What causes seasons on earth?
Seasons happen because Earth's axis is tilted at an angle of about 23.4 degrees. And different parts of Earth receive more solar energy than others.Because of Earth's axial tilt (obliquity), our planet orbits the Sun on a slant which means different areas of Earth point toward or away from the Sun at different times of the year.
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If you want to make more shells (CaCO3) then which direction should the reaction proceed?
Answer:
The reaction will proceed in the reverse direction
Explanation:
Now consider the equation;
CaCO3(s) ⇄CO2(g) + CaO(s)
This is a reversible reaction. The reaction could proceed in either the forward or the reverse reaction depending on the conditions of the reaction. Under certain conditions, the forward reaction is favoured, under certain conditions, the reverse reaction is favoured.
The direction in which the reaction proceeds depends on the desired products as the equilibrium position could be manipulated at will by altering the reaction conditions. If the desire is to produce more CaCO3, then the equilibrium position is manipulated so that it shifts towards the left hand side. This implies that the reverse reaction is favoured.
How do geological processes affect where we find rock and mineral resources (natural resources)?
Answer:
Geological processes can change over time. Water erosion can move sand and dirt and anything. Minerals are everywhere, but they can be buried or washed away by all the geological processes that happen every day.
Explanation:
F2(g)+2Br(aq)=Br(t)+F(aq)
which species is redused?
a)F
b)Br
c)F2
d)Br2
The Answer For Your Question is:
A) F
Which symbol in a chemical equation separates the reactants from the products ?
Answer:
Explanation:
The arrow symbol in a chemical equation separates the reactants from products. A chemical reaction is process in which chemical changes leads to the formation of products from reactants.
Answer: b
Explanation: its b
If 1.27 moles of bromine gas (Br2) react with excess phosphorus (P), how many moles of phosphorus tribromide (PBr3) will be produced?
Answer:
0.85 mole of PBr3.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is given below:
3Br2 + 2P —> 2PBr3
From the balanced equation above,
3 moles of Br2 reacted to produce 2 moles of PBr3.
Therefore, 1.27 moles of Br2 will react to produce = (1.27 x 2)/ 3 = 0.85 mole of PBr3.
Therefore, 0.85 mole of PBr3 is produced by the reaction.
What is the ion in acids that determines if they are safe to eat?
I need an answer but I can´t give anything because i don´t know how
Answer:
Hydrogen ion.
Explanation:
Hydrogen ion is present in the acids which indicates if they are safe for eating or not. The weak acid is present in citrus so it is safe to eat. Weak acid means the concentration of hydrogen ion is lower. If this concentration exceeds so the food is not safe to eat or drink. The pH of acid more than 5 is good to eat but below 5 can adversely affect our body if we consume it.
200 L of a gas at 10 atm pressure and 400 K is cooled to 100 K and reduced to 2 atm pressure. What is the new volume?
Answer:
250L
Explanation:
Data;
V1 = 200L
P1 = 10atm
T1 = 400K
T2 = 100K
P2 = 2atm
V2 = ?
To solve this question, we'll have to use the combined gas equation which is a combination of Boyle's law, Charles law and pressure law.
From combined gas equation,
(P1 × V1) / T1 = (P2 × V2) / T2
P1 × V1 × T2 = P2 × V2 × T1
Solve for V2,
V2 = (P1 × V1 × T2) / P2 × T1
V2 = (10 × 200 × 100) / (2 × 400)
V2 = 200,000 / 800
V2 = 250L
The final volume of the gas is 250L
Asap help
It's very important
Answer:
b. blinking of eyes
Explanation:
Answer:
The answer is B
Explanation:
Blinking is involuntary but also can be done voluntarily.
my Chemistry questions
How can you burn an apple, blueberry, rose and pumpkin without leaving any ashes but retaining the smell of it?
Answer:
candles
Explanation:
if u burn these fruits, it is obvious that there will be ashes but the key hint here is
" retaining the smell"
and what are things that smell and can be fruit scented?
a..... CANDLE
hope this helped :D
Answer:
BY BURNING A CANDLE WITH ITS SCENT
Explanation:
can u answer this?
Mass: 386 g
Volume: 20 cm to the third power
Density: ?
Answer:
Calculate density
Weight/mass
386
g
Volume
20
cm³
Density
19,300
kg/m³
Explanation:
The kinetics of a gas phase reaction of the form A → Products results in a rate constant of 1.308 M⁻¹ s⁻¹. For this reaction, the initial concentration of A is 0.155 M. What is the concentration of A after 0.385 seconds?
Answer:
[tex]C_A=0.144M[/tex]
Explanation:
Hello,
In this case, given the rate constant, we infer this is about a second order reaction, whose equation is:
[tex]\frac{dC_A}{dt}=kC_A^2[/tex]
Thus, by integration we obtain:
[tex]\frac{1}{C_A}= \frac{1}{C_A_0}+kt[/tex]
Hence, we solve for the final concentration after 0.385 s:
[tex]\frac{1}{C_A}= \frac{1}{0.155M}+\frac{1.308}{Ms} *0.385s=\frac{6.955}{M}\\ \\C_A=\frac{M}{6.955} \\\\C_A=0.144M[/tex]
Best regards.
Organic chemistry!!! Plz help
Answer:
3) 2,2-dichloroheptane
Explanation:
2,2-dichloroheptane
This is for chemistry
I need help for this question
Answer:
what is the quetion.......
Explanation:
how many molecules are there in 125 grams of sugar, C12H22O11
Answer:
125
Explanation:
A molecule of sucrose (C12H22O11) has 12 carbon atoms, 22 hydrogen
A 1.8−mL volume of seawater contains about 4.0 × 10^−10 g of gold. The total volume of ocean water is about 1.5 × 10^21 L. Calculate the total worth of all the gold in the world's oceans if the price of gold is $19.96 per gram answer is in scientific notation
Answer: $6.653×10^15
Explanation:
Volume of sea water sample = 1.8mL
Mass of gold in sample = 4.0 × 10^-10 g
Total volume of ocean water = 1.5 × 10^21 L
Converting volume of seawater sample into liters :
1.8mL = (1.8/1000)L = 0.0018L = 1.8×10^-3
If volume of gold in ;
1.8×10^-3L = 4 × 10^-10 g
1.5×10^21 L = X
(1.8×10^-3L)X = [(1.5×10^21) × (4×10^-10) ]
X = [1.5×4(10^21-10)] / 1.8×10^-3
X = 6.0(10^11) / 1.8×10^-3
X = 3.333×(10^11+3)
X = 3.333 × 10^14
Cost of world's gold equals
(3.333 × 10^14) × $19.96
$66.53 × 10^14
Is the molecule saturated or unsaturated
Answer:
Guessing its unsaturated.
Explanation:
A fully saturated compound contains no double or triple bonds. Alternatively, if a molecule contains double or triple bonds, it is considered to be unsaturated.
How much heat is required to vaporize 166g of water at it's boiling point, if water's heat of vaporization is equal to 40.7kJ/mol?
___________________________kJ
Answer:
375.3KJ
Explanation:
The following data were obtained from the question:
Mass of water = 166g
Heat of Vaporisation (ΔHv) = 40.7kJ/mol
Heat (Q) =..?
Next, we shall determine the number of mole in 166g of water. This is illustrated below:
Mass of H2O = 166g
Molar mass of H2O = (2x1) + 16 = 18g/mol
Number of mole = Mass/Molar Mass
Number of mole of H2O = 166/18
Number of mole of H2O = 9.22 moles.
Now, we can obtain the heat required to vaporise the water as shown below:
Q = n·ΔHv
Q = 9.22 mol x 40.7kJ/mol
Q = 375.3KJ
Therefore, the heat required to vaporise the water is 375.3KJ.
When red litmus paper is added to limewater, then what will
be the change in litmus paper? Give reason. Write the chemical
formula of limewater also.
Red Litmus paper turns blue
Answer:
[tex] Ca(OH) _2 [/tex]
Explanation:
In lime water [tex] \red{\bold {RED}} [/tex] litmus paper turns [tex] \blue {\bold {BLUE}} [/tex] because lime water is alkaline.
[tex]formula \: for \: lime \: water : Ca(OH) _2 \\ [/tex]
Calculate the molarity of a solution containing 0.2 mol of sodium hydroxide dissolved in 0.5 L of water. Be sure to report your answer in proper significant figures and use the appropriate symbol.
Answer:
The molarity is 0.4 [tex]\frac{moles}{liter}[/tex]
Explanation:
The Molarity (M) or Molar Concentration is a concentration unit that indicates the number of moles of the solute per liter of solution. In other words, molarity is defined as the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by the expression:
[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]
Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).
In this case:
number of moles of solute (sodium hydroxide)= 0.2 molesvolume= 0.5 LReplacing:
[tex]Molarity (M)=\frac{0.2 moles}{0.5 L}[/tex]
Molarity= 0.4 [tex]\frac{moles}{liter}[/tex]
The molarity is 0.4 [tex]\frac{moles}{liter}[/tex]
A woolly mammoth was found in 1999 buried in the frozen soil of the Siberian tundra. Carbon-14 dating indicated that it had died about 20,000 years ago. Many fossils represent only the partial remains of organisms. However, a complete mammoth with bones, skin, hair, and internal organs intact represented a unique opportunity for scientists to investigate the lifestyle of this animal and the environment in which it lived. The low permeability of the tundra soil helped to preserve the mammoth. Explain why the tundra soil has a low permeability.
Tundra soils are formed at high latitudes which leaves the tundra always very cold. Tundra soils are generally frozen, and are classifed as Gelisols (this means that permafrost are within 100 cm of the soil surface). These permafrost are as a result of the freezing by winter of the underground water that was accumulated in summer. These soils freeze and thaw alot and as result of that, moisture do not permeate the soil easily. Also, due to this harsh temperature and underground permafrost, most organisms that died in the tundra are preserved within the soil.
If the pH indicator bromothymol blue was added to the nitric acid solution, it's colour would be?
Answer:
Yellow
Explanation:
Thymol blue has a brownish-green or reddish-brown color and is a good pH indicator. It changes from red to yellow at a pH 1.2–2.8 ( acidic) and then from yellow to blue at a pH of 8.0–9.6( alkaline).
Nitric acid is a strong acid which means the pH indicator will change to yellow.