The heat is evolved when 24.9 g of propanol (C3H7OH) is burned is 834.15 J
To solve this question, First, we need to find the number of moles present in 24.9 g of propanol.
⇒ Formula
n = M/m................. Equation 1⇒ Where:
n = number of moles M = mass of propanolm = molar mass of propanolFrom the question,
⇒ Given:
M = 24.9 gm = (12×3)+(1×8)+16 = 36+8+16 = 60 g/mol⇒ Substitute these values into equation 1
n = 24.9/60n = 0.415 mol⇒ Finally the heat evolved is
Q = nΔHQ = 0.415(-2010)Q = -834.15 JHence, The heat evolved when propanol is burned is 834.15 J
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Which of the following equations is balanced?
A. 2H2 + O2 → 4H2O
B. 4Na + O2 → 2Na2O
C. Fe2O3 + H2 → 2Fe + 3H2O
D. CH4 + O2 → CO2 + H2O
Answer:
B. 4Na + O2 → 2Na2O
Explanation:
Got it right on the test :)
For balanced equation the mass of reactant is exactly equal to the mass of product. atoms of reactant equal to the atoms of product is called as balanced equation.
What is balanced equation ?
The law of conservation of mass, which states that "the total mass of all the products of reaction in a chemical reaction is equal to the total mass of all the reactants," is satisfied by balancing chemical equations.
A balanced chemical equation, in which the masses of the reactants and products are equal, contains the same amount of atoms of each element on both sides of the equation.
4Na + O₂ ⇒ 2Na₂O₂
In this reaction in reactant there are four number of sodium atom and in product also four number of sodium atom. Similarly total number of oxygen at reactant is equal to the total number of oxygen at product.
Thus, option B is correct.
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Gases at high temperatures and low pressures behave like ideal gases. True or False?
Answer:
Very true
Explanation:
How much heat, in kilojoules, is needed to raise the temperature of 236 g of silver from 8.5oC to 34.9 °C? (cAg = 0.24 J/g°C)
Answer:
1.49kJ
Explanation:
Using the formula as follows;
Q = m × c × ∆T
Where;
Q = amount of heat (joules)
m = mass (g)
c = specific heat of silver (J/g°C)
∆T = change in temperature (°C)
According to the information given in this question;
mass of Silver (Ag) = 236g
c of Ag = 0.24 J/g°C
initial temperature (T1) = 8.5°C
final temperature (T2) = 34.9°C
∆T = T2 - T1 = 34.9 - 8.5 = 26.4°C
Using Q = m × c × ∆T
Q = 236 × 0.24 × 26.4
Q = 1,495.3 Joules
Amount of heat needed to raise the temperature of Silver (Q) in kilojoules is 1495.3/1000 = 1.4953
Q = 1.49kJ
less energy was entering Earth's
2. When more energy enters than exits the Earth system, what happens to temperatures on Earth?
(select one)
The temperatures on Earth increase
The temperatures on Earth decrease
The temperatures on Earth do not change
「ロロロ
Answer:
The temperatures on Earth increase
Explanation:
more energy results in more heat.
PLS HELP ASAP NO LINKS
What type of scientist studies matter and its composition?
Biologist
Chemist
Physicist
Engineer
Answer:
.biology and maybe physics
Answer:
Biologist
ExplanationBiologist Unlike the above type of scientist, geoscientists’ work involves exploring the earth and its internal environment. They study the composition, structure, and processes of the earth by being indoors and outdoors. They contribute to the discovery of mines, petroleum deposits, minerals, and other aspects of the earth.
What is important in order for a radioisotope to provide accurate dating
results?
O A. The half-life should be similar to the age of the object.
B. The radioisotope cannot be part of a decay chain.
O C. The isotope must undergo transmutation.
O D. The item being dated must be very old.
The most important factor to be considered in order for a radioisotope to provide accurate dating simply is:
The half-life should be similar to the age of the object.
The correct answer choice is option a.
Why half-life should be similar to the age of the object in determining accurate dating of a radioisotope.Half-life of radioisotope helps in determining dating accurately simply because it helps to predict the amount of radioactive substance remaining after a given period of time.
In conclusion, it can be perfectly deduced from the explanation given above that the half-life of a radioisotope usually, frequently and most of the time helps to determine the rate at which these substances decay.
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Which example in the video is a physical change?
A) Burning steel wool
B) Mixing chemicals
C) Rusting nail
D) Melting ice cream
D melting ice cream because if u know what a physical change is its a change that you can reverse chimical change are changes you cant reverse so u can freeze back ice cream so :D
Which wave is used to identify the heat given off by distant objects in space
Which procedure is an attempt to correct a genetic disorder by replacing a mutated gene with a normal allele?
O selective breeding
• cloning
O artificial selection
•
gene therapy
gene therapy
Explanation:
Gene therapy, also called gene transfer therapy, the introduction of a normal gene into an individual's order to repair a mutation that causes a genetic disease.
Answer:
C artificial selection
Explanation:
Brainly please
Three students measured the volumes of a pebble whose accepted volume is 2.71 cm3. Which list represents both accurate and precise:
A: 2.60 mL, 2.60 mL, 2.59 mL, 2.59 mL
B: 2.70 mL, 2.69 mL, 2.71 mL, 270 mL
C: 2.75 mL, 2.74 mL, 2.64 mL, 2.71 mL
D: A and B
Answer:
C
Explanation:
Two glass rods are rubbed together. One of the glass rods are brought near (but
does not touch) an uncharged pith ball. Would you expect the pith ball to attract,
repel, or do nothing? Explain why.
Answer:
Do Nothing
Explanation:
Charges are transferred by friction when two different types of bodies are rubbed together. This is known as charging by friction.
However, when two materials of the same type are rubbed together, no charge is transferred from one object to the other hence there is no transfer of charges by friction and none of the two glass rods are charged.
Therefore, when one of the glass rods is brought close but does not touch the pith ball, nothing happens.
Beryllium hydrogen carbonate is more than 3% hydrogen by mass.
True
False
Al2(SO4)3+Mg(NO3)2⟶ What would be the product(s) of this reaction? *These are NOT balanced, just look for the correct products*
Answer:
[tex]Al_2(SO_4)_3+3Mg(NO_3)_2\rightarrow 2Al(NO_3)_3+3MgSO_4[/tex]
Explanation:
Hello there!
In this case, for the given reactants side, we infer this is a double replacement reaction because all the cations and anions are switched around as a result of the chemical change, we infer that the products side include aluminum with nitrate and magnesium with sulfate as shown below:
[tex]Al_2(SO_4)_3+Mg(NO_3)_2\rightarrow Al(NO_3)_3+MgSO_4[/tex]
However, we need to balance since unequal number of atoms are present at both sides, thus, we do that as shown below:
[tex]Al_2(SO_4)_3+3Mg(NO_3)_2\rightarrow 2Al(NO_3)_3+3MgSO_4[/tex]
Thus, we make 6 Al atoms, 3 S atoms, 3 Mg atoms and 30 O atoms on each side in agreement with the law of conservation of mass.
Regards!
State the trend in chemical reactivity as we go down the group for Group I elements Account for
this trend using the electronic structures of the elements.
Answer: The reactivity of group 1 elements increases as you go down the group because: the atoms become larger. the outer electron becomes further from the nucleus. the force of attraction between the nucleus and the outer electron decreases.
The pH of a solution is 8. Some hydrochloric acid is added to the solution. Suggest the pH of the solution after mixing. pH=.......??
Answer:
Probably around 6 because the ph of hydrochloric acid is 3
Explanation:
Find the molarity of 4.18 g MgCI2 in 500mL of water
Answer:
The molarity of MgCl₂ in water is 0.088 mol/L.
Explanation:
The molarity of MgCl₂ can be calculated as follows:
[tex] C = \frac{\eta}{V} = \frac{m}{MV} [/tex]
Where:
C: is the molarity =?
η: is the number of moles of MgCl₂ = m/M
V: is the volume of water = 500 mL = 0.500 L
m: is the mass of MgCl₂ = 4.18 g
M: is the molar mass of MgCl₂ = 95.211 g/mol
Hence, the molarity is:
[tex] C = \frac{m}{MV} = \frac{4.18 g}{95.211 g/mol*0.500 L} = 0.088 mol/L [/tex]
Therefore, the molarity of MgCl₂ in water is 0.088 mol/L.
I hope it helps you!
The first organisms to arrive in an ecosystem?
Select the correct answer.
A circuit is used in which process?
OA. electricity
OB. magnetism
OC. velocity
OD. gravity
Answer:
electricity
Explanation:
A circuit is used in every electrical and electronics operation.
A gas has a volume of 25 ml, at a pressure of 1 atmosphere (1 atm). Increase the volume to 125 ml and the temperature remains constant. What is the new pressure? please help
Explanation:
The new pressure can be found by using the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2 \\[/tex]
Since we're finding the new pressure
[tex]P_2 = \frac{P_1V_1}{V_2} \\[/tex]
We have
[tex]P_2 = \frac{25 \times 1}{125} = \frac{25}{125} = \frac{1}{5} = 0.2 \\ [/tex]
We have the final answer as
0.2 atmHope this helps you
in your notebook,write the appropriate tempo for the following actions.Then demostrate the actions then,demostrate the action in front of your parents,guardian
Answer:
cell :—
•They lack a well-defined nucleus, have a nucleoid instead.
•Usually have double-stranded, circular DNA.
•Do not have mitochondria.
Eukaryotic cell :—
•Have a well-defined nucleus enclosed in the nuclear membrane.
•Have a linear double-stranded nucleus.
•Mitochondria are present.
How many atoms are there in 6.8g of S?
How many formula units are in 325 grams of iron (III) chloride?
Answer:
1.204 × 10^24 formula units
Explanation:
Using the following formula to convert mass of iron (III) chloride to moles;
mole = mass/molar mass
Molar mass of FeCl3 = 56 + 35.5(3)
= 56 + 106.5
= 162.5g/mol
Mole = 325/162.5
mole = 2mol
Next, to calculate the formula units of FeCl3, we multiply the number of moles of FeCl3 by Avagadro number (6.02 × 10^23)
Formula units of FeCl3 = 2 × 6.02 × 10^23
12.04 × 10^23
= 1.204 × 10^24 formula units.
The lower temperature of the air is there more water vapor can hold True or false. Help!!!!!
Answer:
true
Explanation:
PLZ HELP!!!!!! IN YOUR OWN WORDS PLZ! :D
Imagine your cell phone rings. Describe how the sound gets transmitted from your phone to your ear, and then, from your ear to your brain. In your response, be sure to mention the type of wave that a sound wave is, the medium the sound is transmitted through before it gets to your ear, and what happens in your ear once the sound reaches it.
Answer:
SOUND WAVE (carried by thin metal inside the phone) ⇒ELECTRICAL ENERGY (over the wire) ⇒SOUND WAVE (that is heard by someone on the side of the phone)
Explanation:
What is a sound wave?A wave that is comprised of compression and refraction, by which sound is propagated in an elastic medium such as air.
How does sound get transmitted from phone to ear?
The sound waves are carried to a thin metal disk inside the phone, known as the diaphragm, and are converted into electrical energy. The electrical energy travels over wires to another phone and is converted from electrical energy to sound waves again which can be heard by the one on the other end of the phone.
How does sound get transmitted from ear to brain and what happens when sound reaches the ear?Sound waves enter the outer ear and travel through a small passageway (ear canal), which leads to the eardrum.The eardrum vibrates from the coming sound waves and sends these vibrations to three tiny bones in the middle ear. These bones are known as the malleus, incus, and stapes.The bones present in the middle ear amplify the sound vibrations and send these vibrations to the cochlea (the snail-shaped structure that is filled with fluid present in the inner ear). An elastic separation runs from the beginning to the edge of the cochlea, splitting it into upper and lower parts. This separation is called the basilar membrane as it serves as the base on which key hearing structures sit.Once the vibrations result in the fluid inside the cochlea rippling, a traveling wave appears along the basilar membrane. Hair cells (sensory cells) sitting on top of the basilar membrane ride the wave. Hair cells near the broad end of the cochlea detect higher-pitched sounds. Those closer to the center detect lower-pitched sounds, such as a large dog barking.As the hair cells move up and down, microscopic hair-like projections (known as stereocilia) that perch on the peak of the hair cells crash against an overlying structure and bend down. Bending results in pore-like channels, which are at the tips of the stereocilia, opening up. Then chemicals rush into the cells, producing an electrical signal.The auditory nerve carries this electrical signal to the brain, which in return it into a sound that we recognize and understand.In this way, sound reaches our ears.
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A volume of 3.0 L of air is warmed from 50 degrees celsius to 100 degrees celsius. What is the new volume if the pressure remains constant?
Answer:
3.45 L
Explanation:
Temperature and volume are linearly related (when one increases or decreases, so does the other).
Convert the temperature to Kelvin:
50 °C = 323 K
100 °C = 373 K
To find the rate of change, divide 373 by 323 to get roughly 1.15
Multiply the amount of liters by this factor to get your answer
what will litmus paper turn when it reacts with sodium nitrate?
Please Help!! Please, this is due in a couple of minutes, please help
If 8.51×10-2 moles of SO3(g), 0.210 moles of SO2, and 0.354 moles of O2 are at equilibrium in a 15.4 L container at 1.25×103 K, the value of the equilibrium constant, K, is ____
Answer: The value of equilibrium constant, K, is [tex]7.74 \times 10^{-4}[/tex].
Explanation:
The reaction equation is as follows.
[tex]2SO_{3}(g) \rightleftharpoons 2SO_{2}(g) + O_{2}(g)[/tex]
Now, the expression for equilibrium constant of this reaction is as follows.
[tex]K = \frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}[/tex]
Substitute the given values into above expression as follows.
[tex]K = \frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}\\= \frac{(\frac{0.210}{15.4})^{2} \times (\frac{0.354}{15.4})}{(\frac{8.51 \times 10^{-2}}{15.4})}\\= 7.74 \times 10^{-4}[/tex]
Thus, we can conclude that the value of equilibrium constant, K, is [tex]7.74 \times 10^{-4}[/tex].
Why is carbon dioxide a covalent bond?
Explanation:
One atom of carbon (2.4) combines with two atoms of oxygen (2.6) to form the compound carbon dioxide CO2 (only the outer shell of carbon's electrons are shown). ... The carbon dioxide molecule is held together by the strong C=O. carbon–oxygen double covalent bonds by sharing electrons.
If you stay at 90 degrees Celsius and a gas in a liquid solution has a pressure of 2 atm, what solubility should it have if it has a solubility of 64 g/L at a pressure of 8 atm?
Answer:
im not sure
Explanation:
need these 2 answered asap pls
Answer:
im not a brain wiz but i think 20
Explanation: