Answer: When fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
Explanation:
The chemical energy present in fuels actually releases when these fuels are burned or by combustion.
Hence when fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
For example, gasoline present in vehicles burns and undergoes chemical change which is then converted into thermal energy. This thermal energy then converts into mechanical energy due to which car moves.
Thus, we can conclude that when fuels are burned, the chemical energy that is released can be used to generate another form of energy, such as heat, light, motion, or electricity. This is called combustion.
The area of a telescope lens is 6507 x 10^3 mm^2. What is the area in square feet, enter your answer in scientific notation. If it takes a technician 51.6 s to polish 1.68 x 10^2 mm^2 how long does it take her to polish the entire lens ?
Answer: the area of the telescope lens is \textit{0,08507 ft}
Explanation: Happy I could help!
You need to prepare 1 L of the citric acid/citrate buffer. You have chosen to use Method 1 (see lab presentation). Calculate the pH of a solution prepared by mixing 300 mL of 0.45 M citric acid acid and 100 mL of 0.65 M NaOH plus water to a final volume of one liter. The Ka of citric acid is 7.24 x 10-4.
Answer:
3.11 is the pH of the buffer
Explanation:
The pH of a buffer is obtained using H-H equation:
pH = pKa + log [Conjugate base] / [Weak acid]
Where pH is the pH of the buffer, pKa = -log Ka = 3.14 for the citric buffer and [] could be taken as the moles of each species.
The citric acid,HX (Weak acid), reacts with NaOH to produce sodium citrate, NaX (weak base) and water:
HX + NaOH → H2O + NaX
That means the moles of NaOH added = Moles of sodium citrate produced
And the resulitng moles of HX = Initial moles - Moles NaOH added
Moles HX and NaX:
Moles NaOH = 0.100L * (0.65mol / L) = 0.065 moles NaOH = Moles NaX
Moles HX = 0.300L * (0.45mol / L) = 0.135 moles HX - 0.065 moles NaOH = 0.070 moles HX
Replacing in H-H equation:
pH = 3.14 + log [0.065mol] / [0.070mol]
pH = 3.11 is the pH of the buffer
What is the [OH-] in a solution if the [H*] = 1.2 x 10-3 M?
We know that [OH⁻] * [H⁺] = 10⁻¹⁴
plugging the value of [H⁺]
[OH⁻] * 1.2 * 10⁻³ = 10⁻¹⁴
[OH⁻] = 10⁻¹⁴ * (10³/1.2)
[OH⁻] = 833.3 * 10⁻¹⁴
[OH⁻] = 8.33 * 10⁻¹²
pcl3 compound stable but don't follows octet rule what is the reason behind?
PLEASE HELP ME!!!!!!!
Answer:
The heat capacity of the metal underneath the gold is 0.431 J/g°C
Explanation:
Using the formula as outlined in the image:
Q = m × c × ∆T
Where;
Q = amount of heat energy (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to the information in this question;
Q = 503.9J
m = 23.02g
c = ?
∆T = 74°C - 23.2°C = 50.8°C
Using Q = m × c × ∆T
c = Q ÷ m∆T
c = 503.9 ÷ (23.02 × 50.8)
c = 503.9 ÷ 1169.42
c = 0.431 J/g°C
From the above heat capacity of the metal underneath the gold, it is obvious that the metal is not pure gold (c = 0.129J/g°C)
Write a conclusion statement that addresses the following questions: • Explain what the color change indicated about the changes in the concentrations of Co(H2O)62+ and CoCl42– in each trial. • Do your data support or fail to support your hypothesis (include examples)? • How do you think the investigation can be explored further?
When the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.
What is equilibrium?The term equilibrium in a chemical reaction connotes that the forward and the revers reactions proceed at the same rate. Let us note that Co(H2O)6^2+ is pink in color while CoCl4^2– is blue in color.
As such, when the concentration of the HCl is varied, the color of the solution is changed as the equilibrium position moves to the left or right.
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True or False: "Endothermic Reactions absorbs energy in the form of heat."
Answer:
true
Explanation:
Endo means inside
but exo means outside
an Endo thermic reaction sounds like it wouldn't be the one to give off heat, so it might be storing heat.
How many moles are 2.60 * 10 ^ 27 atoms of Silicon?
Answer:
~4,317.5 moles of Silicon
Explanation:
Using Avogadro's contant we know that:
1mole = 6.022 x 10^23 atoms
So,to calculate the number of moles in 2.60 x 10^27 atoms of Silicon:
=(2.60 x 10^27 x 1)/(6.022 x 10^23)
~4,317.5 moles of Silicon
Hope it helps:)
How many moles of MgCO3 are present in 252.939 grams of MgCO3?
A. 2
B. 3
C.5
D.6
Answer:
Hello, I was doing this and from my caluclations it should be :
Explanation:
3 Moles.
The three moles of MgCO3 are present in 252.939 grams of MgCO3.
So, option B is correct one .
What is molar mass?The molar mass of substance is equal to mass of one mole of that substance.
Example: Molar mass of MgCO3 is equal to mass of one mole of MgCO3.
Molar mass of Mg = 24.305 u
Molar mass of C = 12.011 u
Molar mass of O = 15.999 u
Molar mass of MgCO3 = Molar mass of Mg + Molar mass of C + Molar mass of O*3
Molar mass of MgCO3 = 24.305 + 12.011 + 15.999 * 3
Molar mass of MgCO3 = 84.3139 gram
Molar mass of MgCO3 contain 84.3139 gram
So, 252.939 grams of MgCO3 = 252.939 grams/84.3139 gram
252.939 grams of MgCO3 = 2.999 moles
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cloruro de litio mas sodio
Answer:
El cloruro de litio se utiliza para fabricar litio metálico. El cloruro de litio se funde y electroliza. Esto produce litio metálico líquido.
Explanation:
sowwy si mi español es malo
Answer:
give him brainliest
Explanation:
Map
Formulate your hypothesis.
List down the materials.
• Write the methods.
Answer:
How to Formulate an Effective Research Hypothesis
State the problem that you are trying to solve. Make sure that the hypothesis clearly defines the topic and the focus of the experiment.
Try to write the hypothesis as an if-then statement. ...
Define the variables.
Explanation:
The compound aluminum nitride () is a compound semiconductor having mixed ionic and covalent bonding. The electronegativities for and are 1.5 and 3.0 respectively. Calculate the fraction of the bonding that is ionic.
Answer:
Fraction ionic = 0.43
Explanation:
To solve this question, we must, as first, find the fraction of the bond that is covalent using the equation:
Fraction Covalent = exp (-0.25*(Enitride - EAl)²)
Fraction covalent = exp (-0.25*(3.0- 1.5)²)
Fraction covalent = exp (-0.25*2.25)
Fraction covalent = exp (-0.5625)
Fraction covalent = 0.57
As:
1 = Fraction Covalent + Fraction Ionic:
Fraction ionic = 1 - 0.57
Fraction ionic = 0.43
how do the hydrosphere and atmosphere interact? give an example
Answer:
Evaporation
Explanation:
Water in the ocean, rivers, lakes, etc. is part of the hydrosphere, and when that water evaporates it enters the atmosphere
What type of intermolecular forces are due to
the attraction between temporary dipoles
and their induced temporary dipoles?
Select one:
a. London dispersion
b. Metallic bond
C. Covalent bond
d. Hydrogen bond
e. lonic bond
Answer:
A. London dispersion
Explanation:
London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make the atoms form temporary dipoles.
The intermolecular forces are due to the attraction between temporary dipoles, and their induced temporary dipoles are the type of London dispersion force. Therefore, option A is correct.
What is london dispersion force ?When the electrons in two nearby atoms occupy positions that cause the atoms to temporarily form dipoles, the consequence is the London dispersion force, a transient attractive force. The term "induced dipole-induced dipole attraction" is frequently used to describe this effect.
The electron density of a molecule is redistributed towards another molecule because the electrons in nearby molecules "flee" when they repel one another. This is typically explained as the instantaneous production of attracted dipoles.
The material's atomic or molecular weight affects the London dispersion forces. More electrons and stronger London forces are present in heavier atoms or molecules. They are therefore more difficult to melt or boil.
Thus, option A is correct.
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If the molecule has n-C2 axes perpendicular to its Cn axis, choose True. Otherwise, choose False. Be sure to build a model or draw the structure before selecting your answer. If needed, search for the molecular structure online or in a textbook.XeF4[PdCl4]2−naphthalenefuran, C4H4O
Answer:
XeF4 True
[PdCl4]2− True
naphthalene True
Furan False
C4H4O False
Explanation:
From the given information:
Only XeF4; [PdCl4]2−; naphthalene are true. This is because their molecules contain -nC₂ axis which is perpendicular to the Cn axis. The image attached below shows the structural formula of each compound, there below, we can see that Furan only possesses one C₂ axis but not -nC₂ ⊥ C₂.
A radioactive material, with half-life of six months, has 100 thousand unstable nuclei.
(a) Find the number of unstable nuclei present after three months.
(b) What will be its activity at this time (after three months)?
Answer:
See Explanation
Explanation:
Given that;
N/No = (1/2)^t/t1/2
Where;
No = amount of radioactive isotope originally present
N = A mount of radioactive isotope present at time t
t = time taken
t1/2 = half life
N/1000=(1/2)^3/6
N/1000=(1/2)^0.5
N = (1/2)^0.5 * 1000
N= 707 unstable nuclei
Since the value of the initial activity of the radioactive material was not given, the activity of the radioactive material after three months is given by;
Decay constant = 0.693/t1/2 = 0.693/6 months = 0.1155 month^-1
Hence;
A=Aoe^-kt
Where;
A = Activity after a time t
Ao = initial activity
k = decay constant
t = time taken
A = Aoe^-3 *0.1155
A=Aoe^-0.3465
How many Grams of NO is produced if 12g of O2 is combined with excess ammonia?
Answer:
9g
Explanation:
moles O2 = mass / Mr = 12 / 2(16.0) = 0.375
ratio O2 : NO = 5:4
moles NO produced = 0.375 * 4/5 = 0.3
mass NO = Mr * mol = (14.0+16.0) * 0.3 = 9g
The Grams of NO is produced if 12g of O2 is combined with excess ammonia is 80 gram.
What is NO?The full form of NO is nitrogen oxide Nitrogen belong to the 15th group of the periodic table with molar mass of 14 and oxygen belong to the 16th group of the periodic table.
In the given their are 4 molecules of each nitrogen and oxygen and mass of O2 is given whereas, mass of nitrogen for 4 molecule will be 56 gram.
Grams of NO = 14 × 4 + 12 × 2
Grams of NO = 80 grams.
Therefore, the mass of NO for the given reaction is combined with excess ammonia is 80 gram.
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explain the trend in boling point of alcohols in their homologous series
Explanation:
The boiling point of alcohols also increase as the length of hydrocarbon chain increases
The boiling point of alcohols also increase as the length of hydrocarbon chain increases.
Why boiling points of alcohols increases as the length of hydrocarbon chain increasesSince, boiling point depends upon type of bonds present in the molecules.If molecules have hydrogen bonding then boiling point is higher than others because hydrogen bond is stronger bond.So, higher energy or temperature required to break these bond or overcomes the inter molecular force of attraction.Since, alcohol contains hydrogen bonding. So, its boiling points are higher as compare to other compounds.Since, boiling points is also directly proportional to molar mass of molecules. So, molecule have higher molar mass has comparatively high boiling point.Example: An alcohols with lower hydrocarbon chain has lower boiling points as compare to alcohols with higher hydrocarbon chain.To learn more about alcohols,
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HELP PLZ
Calculate the percent composition by mass of iron in Fe(NO3)3
What is the main function of a nucleic acid?
A. It allows polysaccharides to form.
OB. It stores lipids inside the proteins.
C. It contains instructions for making proteins.
OD. It is a catalyst in chemical reactions.
The main function of nucleic acid is It stores lipids inside the proteins.
Nucleic acidsNucleic acids are large biomolecules that play essential roles in all cells and viruses. A major function of nucleic acids involves the storage and expression of genomic information. Deoxyribonucleic acid, or DNA, encodes the information cells need to make proteins. A related type of nucleic acid, called ribonucleic acid (RNA), comes in different molecular forms that play multiple cellular roles, including protein synthesis.
Nucleic acids are made of nitrogen-containing bases, phosphate groups, and sugar molecules. Each type of nucleic acid has a distinctive structure and plays a different role in our cells. Researchers who first explored molecules inside the nucleus of cells found a peculiar compound that was not a protein or a lipid or a carbohydrate. It was new. The discovery of this molecule — nuclein, which upon further understanding became nucleic acid — set in motion the eventual discovery of DNA.
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If 1.00 mol of an ideal monatomic gas initially at 74 K absorbs 100 J of thermal energy, what is the final temperature
Answer:
T = 82 K
Explanation:
The computation of the final temperature is shown below;
Given that
T_0 denotes the initial temperature of the gas i.e. 74 K
T denotes the final temperature of the gas = ?
n denotes number of moles of monoatomic gas i.e. 1.00 mol
R denotes universal gas constant = 8.314
c denotes the heat capacity at constant volume i.e.
= (1.5) R = (1.5) (8.314)
= 12.5
Q denotes the Amount of heat absorbed i.e 100 J
We know that
Amount of heat absorbed is provided as
Q = n c (T - T_0)
100 = (1) (12.5) (T - 74)
T = 82 K
Now we need to find the amount of NF3 that can be formed by the complete reactions of each of the reactants. If all of the N2 was used up in the reaction, how many moles of NF3 would be produced
The question is incomplete, the complete question is:
Nitrogen and fluorine react to form nitrogen fluoride according to the chemical equation:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
A sample contains 19.3 g of [tex]N_2[/tex] is reacted with 19.3 g of [tex]F_2[/tex]. Now we need to find the amount of [tex]NF_3[/tex] that can be formed by the complete reactions of each of the reactants.
If all of the [tex]N_2[/tex] was used up in the reaction, how many moles of [tex]NF_3[/tex] would be produced?
Answer: 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.
Excess reagent is defined as the reagent which is left behind after the completion of the reaction.
In the given chemical reaction, [tex]N_2[/tex] is considered as a limiting reagent because it limits the formation of the product and it was completely consumed in the reaction.
We are given:
Mass of [tex]N_2[/tex] = 19.3 g
Molar mass of [tex]N_2[/tex] = 28.02 g/mol
Putting values in equation 1:
[tex]\text{Moles of }N_2=\frac{19.3g}{28.02g/mol}=0.689mol[/tex]
For the given chemical reaction:
[tex]N_2(g)+3F_2(g)\rightarrow 2NF_3(g)[/tex]
By the stoichiometry of the reaction:
1 mole of [tex]N_2[/tex] produces 2 moles of [tex]NF_3[/tex]
So, 0.689 moles of [tex]N_2[/tex] will produce = [tex]\frac{2}{1}\times 0.689=1.378mol[/tex] of [tex]NF_3[/tex]
Hence, 1.378 moles of [tex]NF_3[/tex] are produced in the reaction.
Analyses of enzymes found in the blood are used as indicators that tissue damage (heart, liver, muscle) has occurred and resulted in the leakage of cellular enzymes into the bloodstream.
a. True
b. False
Answer:
True.
Explanation:
Yes, analyses of enzymes found in the blood are used as indicators of tissue damage in the heart, liver, muscle etc has occurred. This leakage of enzymes into the bloodstream tells us whether the tissue is damaged or not. Lactate dehydrogenase is a type of enzyme which is used as indicator which is responsible for the interconverts lactate and pyruvate. The concentration of this enzyme in the blood tells us about tissue damage.
Answer:
a. True
Explanation:
The co enzyme used for this reaction is NADH+, here H+ acts as co substrate.
This is required to find the tissue damage that has occurred in our body which resulted in leakage of cellular enzymes into the bloodstream.
This coenzyme is used for conversion of lactose dehydrogenase.
When Rutherford performed his experiment, only 1 in 20,000 alpha particles bounced straight back or were
deflected greatly. The rest went straight through the gold foil.
a What does this indicate about the probability of actually hitting anything?
Answer:
when rutherford performed his experiment, only 1 in 20,000 alpha particles bounced straight back or were deflected greatly. the rest went straight through the gold foil. e) based on this evidence, what is in atom's center? positively charged particles.
Explanation:
问题2
15
The reaction causes the temperature of its surroundings to decrease is
therefore heat is
by the reaction.
and
Select the two words that best complete this sentence.
a. endothermic, absorbed
b. exothermic, released
c. exothermic, absorbed
d. endothermic, released
Answer:
a endothermic, absorbed
The specific heat of palladium is 0.239 J/g°C. How much heat (q) is released when a 10.0 g piece of platinum cools from 100.0°C to 50.0°C?
Answer:
119.5 J
Explanation:
First we calculate the temperature difference:
ΔT = 100 °C - 50 °C = 50 °CThen we can calculate the heat released by using the following formula:
q = Cp * ΔT * mWhere q is the heat, Cp is the specific heat, ΔT is the temperature difference and m is the mass.
We input the data:
q = 0.239 J/g°C * 50 °C * 10.0 gq = 119.5 JWhat mass of oxygen will react with 2.64 g of magnesium?
2Mg(s) + O2(g) → MgO(s)
Answer:
[tex](24 \times 2) \: g \: of \: magnesium \: reacts \: with \: (16 \times 2) \: g \: of \: oxygen \\ 2.64 \: g \: of \: magnesium \: will \: react \: with \: ( \frac{2.64 \times 16 \times 2}{24 \times 2} ) \: g \\ = 1.76 \: g \: of \: oxygen[/tex]
Calculate the number of hydrogen atoms present in 40g of urea, (NH2)2CO
Answer: There are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{40 g}{60 g/mol}\\= 0.67 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] atoms.
So, the number of atoms present in 0.67 moles are as follows.
[tex]0.67 mol \times 6.022 \times 10^{23} atoms/mol\\= 4.035 \times 10^{23} atoms[/tex]
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
[tex]4 \times 4.035 \times 10^{23} atoms\\= 16.14 \times 10^{23} atoms[/tex]
Thus, we can conclude that there are [tex]16.14 \times 10^{23}[/tex] atoms of hydrogen are present in 40g of urea, [tex](NH_{2})_{2}CO[/tex].
A gas stp is 4.38 L how many moles are there ?
Answer:
There are 0.195 moles.
Explanation:
1 mol of any gas under STP (meaning 1 atm and 273 K) will occupy 22.4 liters.
With the information above in mind, we can calculate how many moles will occupy 4.38 liters:
4.38 L * 1 mol / 22.4 L = 0.195 molIn 4.38 liters of a gas at STP there will be 0.195 moles.
Predict the effect of an eightfold pressure increase on the equilibriunm composition of the reaction 3 Nalg) + H21g) =2 NaHlg)
According to Le cha telier's principle when we increase the pressure of a equilibrium reaction the reaction shift to the side where few moles of gas present.
Your reaction (Notice - I guess the reaction you written is wrong, but still I'm solving with your given prediction)
3NaI (g) + H2 (g) = 2NaHI (g)
Where access of sodium iodide is reacting with Hydrogen gas to form NaHI molecule.
Number of moles of gas on reaction side - 3+2 = 5 moles
Number of moles of gas on product side - 2 moles
Conclusion- the reaction will shift to the right of the reaction
According to Le cha telier's principle when we increase the pressure of a equilibrium reaction the reaction shift to the side where few moles of gas present.
Your reaction (Notice - I guess the reaction you written is wrong, but still I'm solving with your given prediction)
3NaI (g) + H2 (g) = 2NaHI (g)
Where access of sodium iodide is reacting with Hydrogen gas to form NaHI molecule.
Number of moles of gas on reaction side - 3+2 = 5 moles
Number of moles of gas on product side - 2 moles
Conclusion- the reaction will shift to the right of the reaction