Answer:
is always exothermic
Explanation:
You see, whether a process is endothermic or exothermic depends on the result of the operation; ΔHreaction= ΔHproducts - ΔHreactants.
If the enthalpy of reactants exceeds that of the products, then the process is exothermic.
We should remember that the energy of isolated atoms is always higher than the energy of the compound formed when the atoms bond together. Hence bond making is an exothermic process.
Energy is used to form bonds and released when they are broken, bond-breaking is considered to be endothermic. Additionally, the creation of bonds is typically an exothermic process. The formation of chemical bonds from separated atoms is exothermic. The correct option is 4.
When bonds are created in the products of exothermic processes, more energy is produced than is required to break the bonds between the reactants. The temperature of the reaction mixture rises as a result of exothermic reactions. Endothermic chemical processes are those that generally absorb (or use) energy.
An attraction between atoms or ions is referred to as a chemical bond. Atoms trade or exchange valence electrons to create bonds.
Thus the correct option is 4.
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Evaluate
0.411 + 9.9 + 0.8
and round the answer appropriately,
Answer:
the answer is 11.111 and when you round it to the nearest one it’s 11, but to the nearest tenth it’s 10
Explanation:
what makes science reliable
Answer:
Science is really reliable because there is research and math and brains. Actual science are results from experiments, so it's mainly always correct.
Explanation:
A sample of iron (III) chloride has a mass of 26.29g. How many moles would this be?
0.1621 mol FeCl₃
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Compounds
Determining compound formulasAtomic Structure
Reading a Periodic TableUsing Dimensional AnalysisExplanation:Step 1: Define
26.29 g FeCl₃ (iron (III) chloride)
Step 2: Identify Conversions
Molar Mass of Fe - 55.85 g/mol
Molar Mass of Cl - 35.45 g/mol
Molar Mass of FeCl₃ - 55.85 + 3(35.45) = 162.2 g/mol
Step 3: Convert
Set up: [tex]\displaystyle 26.29 \ g \ FeCl_3(\frac{1 \ mol \ FeCl_3}{162.2 \ g \ FeCl_3})[/tex]Multiply: [tex]\displaystyle 0.162084 \ moles \ FeCl_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 4 sig figs.
0.162084 mol FeCl₃ ≈ 0.1621 mol FeCl₃
according to the kinetic molecular theory the pressure exerted by a sample of gas at constats volume doubles when the absolute temperature is doubled because
Answer: gas molecules will hit the container walls more frequently and with greater force
Explanation:
According to the postulates of kinetic molecular theory:
1. The pressure exerted by a gas in a container results from collisions between the gas molecules and the container walls.
2. The average kinetic energy of the gas molecules is proportional to the kelvin temperature of the gas.
When the temperature is increased, so the average kinetic energy and the rms speed also increase. This means that the gas molecules will hit the container walls more frequently and with greater force because they are all moving faster. This increase the pressure.
At 400K both compounds are gases. At this temperature, which compound, CH4(g) or CCl4(g) , behaves more like an ideal gas
Answer:
CH4
Explanation:
The ideal gas behavior of individual gases often depend on the magnitude of intermolecular interaction between the molecules of the gas as well as the presence or absence of polar bonds.
In CCl4, there are polar bonds and the presence of the more electronegative chlorine atom in the molecule and consequently a greater degree of intermolecular interaction at 400K compared to CH4 which contains only non polar bonds.
Therefore, CH4 displays greater ideal gas behavior at 400K than CCl4.
Calculate the volume in liters of a 2.3*10^-6 mercury(I) chloride solution that contains of mercury(I) chloride . Round your answer to significant digits.
Answer:
2.00x10⁵L
Explanation:
...That contains 125g of mercury(I) chloride...
The molarity, M, of a solution represents the moles of solute (Mercury(I) chloride), per liter of solution.
To solve this question, we need to determine the moles of mercury(I) chloride present in 125g. Then, with molarity, we can find the volume of the solution:
Moles Mercury(I) chloride -Molar mass: 271.52g/mol-:
125g * (1mol / 271.52g) = 0.460 moles
Volume:
0.460 moles * (1L / 2.3x10⁻⁶mol) =
2.00x10⁵LGaseous methane CH4 reacts with gaseous oxygen gas O2 to produce gaseous carbon dioxide CO2 and gaseous water H2O. What is the theoretical yield of water formed from the reaction of 15.4g of methane and 90.3g of oxygen gas
Answer:
50.8 g
Explanation:
Equation of reaction.
[tex]CH_4 + 2O_2 \to CO_2 + 2H_2O[/tex]
From the given information, the number of moles of methane = mass/ molar mass
= 15.4 g / 16.04 g/mol
= 0.960 mol
number of moles of oxygen gas = 90.3 g / 32 g/ mol
= 2.82 mol
Since 1 mol of methane requires 2 moles of oxygen
Then 0.960 mol of methane will require = 0.960 mol × 2 = 1.92 mol of oxygen gas
Thus, methane serves as a limiting reagent.
2.82 mol oxygen gas will result in 2.82 moles of water
So, the theoretical yield of water = moles × molar mass
= 2.82 mol × 18.01528 g/mol
= 50.8 g
Sulfur dioxide and oxygen react to form sulfur trioxide, like this: (g) (g) (g) Also, a chemist finds that at a certain temperature the equilibrium mixture of sulfur dioxide, oxygen, and sulfur trioxide has the following composition: compound pressure at equilibrium Calculate the value of the equilibrium constant for this reaction. Round your answer to significant digits.
Answer:
[tex]Kp=9.2x10^{-3}[/tex]
Explanation:
Hello!
In this case, for the undergoing chemical reaction at equilibrium:
[tex]2SO_2(g)+O_2(g)\rightleftharpoons 2SO_3(g)[/tex]
Which means that pressure-based equilibrium constant is computed via the following equilibrium expression:
[tex]Kp=\frac{p_{SO_3}^2}{p_{SO_2}^2p_{O_2}}[/tex]
Thus, by plugging in the given pressures at equilibrium, the required Kp turns out:
[tex]Kp=\frac{55.0^2}{70.2^2*66.7}\\\\Kp=9.2x10^{-3}[/tex]
Best regards!
someone pls help I’m not sure which one it is
Answer:
Space
Explanation:
Sound waves can't travel through space but radiant energy from the sun can, which is how it reaches Earth.
How many particles of argon (Ar) are present in 18.4L of argon? please
Answer:
Explanation:
C
[tex]4.9 \times 10^{23}[/tex] are present in 18.4L of argon (Ar).
To calculate the amount of particles present in a given amount of volume, it is necessary to have knowledge of the molar volume:
[tex]1 mol = 22.4L[/tex]
Thus, in 22.4L there is 1 mol of an element, remembering that:
[tex]1 mol = 6\times10^{23}[/tex] particles
In this way, it is enough to relate the value of the molar volume given with the value requested by the question:
[tex]\frac{6\times10^{23}particles}{xparticles} = \frac{22.4L}{18.4L}[/tex]
[tex]x = 4.9 \times 10^{23}[/tex] particles
So, [tex]4.9 \times 10^{23}[/tex] are present in 18.4L of argon (Ar).
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Trees are to renewable as____is to nonrenewable.
A. water
B. oil
C. corn
D. paper
Answer:
b.oil
Explanation:
oil is a nonrewnewable resource
which type of organism carries out cellular respiration
Answer:Prokaryotic cells carry out cellular respiration within the cytoplasm and eukaryotic cells carry out respiration in the mitochondria
Explanation:
0.32 L of HNO3 is titrated to equivalence using 0.12 L of 0.2 M NqOH. What is the concentration of the HNO3
Answer:
[tex]M_{acid}=0.075M[/tex]
Explanation:
Hello!
In this case, since the reaction between NaOH and HNO3 is:
[tex]NaOH+HNO_3\rightarrow NaNO_3+H_2O[/tex]
Whereas there is a 1:1 mole ratio between the acid and base, thus, we can write:
[tex]M_{acid}V_{acid}=M_{base}V_{base}[/tex]
In such a way, solving for the concentration of the acid, HNO3, we obtain:
[tex]M_{acid}=\frac{M_{base}V_{base}}{V_{acid}}[/tex]
Therefore, by plugging in we obtain:
[tex]M_{acid}=\frac{0.12L*0.2M}{0.32L}\\\\ M_{acid}=0.075M[/tex]
Best regards!
Which is the largest group of mollusks?
bivalves
sea cucumbers
cephalopods
gastropods
Answer:
D) Gastropod
Explanation:
It's higher classification is Mollusca on go o gle
Which of the following Group 17 elements is the least reactive?
The given question is incomplete. The complete question is :
Which of the following Group 17 elements is the least reactive
a) Flourine
b) Chlorine
c) Astatine
d) Iodine
Answer: c) Astatine
Explanation:
Halogen is the name given to Group 17 family with general electronic configuration of [tex]ns^2np^5[/tex] which have 7 valence electrons and thus easily gain one electron to attain stable configuration.
As we move down the group from flourine to chlorine to bromine to iodine to astatine , the valence shell moves farther from nucleus and thus tendency to accept the electron decreases and thus reactivity also decreases.
Thus Astatine is the least reactive of all.
Directions: The picture below shows a model of Earth's layers. Use the picture to answer
any questions that follow.
Layer 5
Layer 4
Layer 3
Layer 2
Layer 1
1. Which layers compose the lithosphere?
A layers 6 and 4
B layers 4 and 3
a layers 3 and 2
D layers 2 and 1
Answer:
hfghfhjcbnggf
Explanation:
layer1
layer 2
You have a solid 7.00 gram mixture of sodium nitrate and silver nitrate. You add distilled water to dissolve the solids. Now you have aqueous solutions of sodium nitrate and silver nitrate. Next you add excess sodium chloride which results in a precipitate forming. You collect and dry the precipitate that forms and it has a mass of 2.54 grams. Write a balanced net ionic equation for the reaction that occurred. Determine the percent silver nitrate in the original mixture by mass assuming 95.9% actual yield.
Answer:
Net ionic equation: Ag⁺(aq) + Cl⁻(aq) → AgCl(s)
44.9% as AgNO₃
Explanation:
When sodium nitrate, NaNO₃ and silver nitrate, AgNO₃ are dissolved in water, the Na⁺, NO₃⁻ and Ag⁺ ions are formed.
Then, the addition of NaCl (Na⁺ and Cl⁻) produce AgCl⁻ as precipitate. The net ionic equation is:
Ag⁺(aq) + Cl⁻(aq) → AgCl(s)If 2.54g of AgCl are formed and represents the 95.9% of yield. The real amount of AgCl is:
2.54g AgCl * (100% / 95.9%) = 2.65g AgCl.
In moles (Molar mass AgCl = 143.32g/mol):
2.65g AgCl * (1mol / 143.32g) = 0.0185 moles of AgCl = Moles of AgNO₃
Because all Ag comes from AgNO₃
Thus, the original mass of silver nitrate and its precentage is (Molar mass AgNO₃ = 169.87g/mol):
0.0185 moles AgNO₃ * (169.87g / mol) = 3.14g of AgNO₃
Percentage:
3.14g AgNO₃ / 7.00g * 100 =
44.9% as AgNO₃Explain why it is necessary for a chemical reaction to balance.
How many moles are in 563.9 grams of arsenic?
Answer:
No. of moles, n = 7.52 moles
Explanation:
Given that,
Mass, m = 563.9 grams
Molar mass of arsenic = 74.92 g/mol
We need to find the number of moles in 563.9 grams of arsenic. Let it is denoted by n. It is equal to given mass divided by total molar mass.
[tex]n=\dfrac{563.9 }{74.92}\\\\=7.52\ \text{moles}[/tex]
So, there are 7.52 moles in 563.9 grams of arsenic.
An aqueous solution of ethanol, CH3CH2OH, has a concentration of 5.82 mol/L and has a density of 0.957 g/mL. What are the mass percent and mole fraction of CH3CH2OH in this solution
Answer:
1. Mass percent of ethanol = 28.02 %.
2. Mole fraction of ethanol = 0.13.
Explanation:
1. To find the mass percent we need to use the following equation:
[tex]\%_{m/m} = \frac{m_{e}}{m_{s}} \times 100[/tex]
Where:
[tex]m_{e}[/tex] is the mass of ethanol
[tex]m_{s}[/tex] is the mass of the solution
We need to calculate the mass of ethanol and the mass of the solution:
[tex] d = \frac{m_{s}}{V} [/tex]
Where:
d: is the density of the solution = 0.957 g/mL
V: is the volume = 1 L
[tex] m_{s} = d*V = 0.957 \frac{g}{mL}*\frac{1000 mL}{1 L}*1 L = 957 g [/tex]
Now, from the concentration we can find the mass of ethanol:
[tex] C = \frac{n_{e}}{V} = \frac{m_{e}}{M_{e}*V} [/tex]
Where:
[tex]M_{e}[/tex]: is the molar mass of ethanol = 46.07 g/mol
[tex]n_{e}[/tex]: is the number of moles of ethanol = m/M
[tex] m_{e} = C*M*V = 5.82 \frac{mol}{L}*46.07 \frac{g}{mol}*1 L = 268.13 g [/tex]
Finally, the mass percent of ethanol is:
[tex]\%_{m/m} = \frac{268.13 g}{957 g} \times 100 = 28.02 \%[/tex]
2. The mole fraction of ethanol is given by:
[tex] \chi_{e} = \frac{n_{e}}{n_{s}} [/tex]
The number of moles of ethanol is:
[tex]n_{e} = \frac{m_{e}}{M_{e}} = \frac{268.13 g}{46.07 g/mol} = 5.82 moles[/tex]
And the moles of the solution is:
[tex] n_{s} = n_{e} + n_{w} [/tex]
Where w is for water
[tex] n_{s} = n_{e} + \frac{m_{w}}{M_{w}} [/tex]
[tex] n_{s} = n_{e} + \frac{m_{s} - m_{e}}{M_{w}} [/tex]
[tex]n_{s} = 5.82 moles + \frac{957 g - 268.13 g}{18 g/mol} = 44.09 moles[/tex]
Hence, the mole fraction of ethanol is:
[tex]\chi_{e} =\frac{5.82 moles}{44.09 moles}=0.13[/tex]
I hope it helps you!
If you had excess chlorine, how many moles of of aluminum chloride could be produced from 11.0 g of aluminum
Answer: 0.407 moles of aluminum chloride could be produced from 11.0 g of aluminum.
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of aluminium}=\frac{11.0g}{27g/mol}=0.407moles[/tex]
[tex]2Al+3Cl_2\rightarrow 2AlCl_3[/tex]
According to stoichiometry :
[tex]Al[/tex] is the limiting reagent as it limits the formation of product and [tex]Cl_2[/tex] is the excess reagent.
As 2 moles of [tex]Al[/tex] give = 2 moles of [tex]AlCl_3[/tex]
Thus moles of [tex]Al[/tex] give =[tex]\frac{2}{2}\times 0.407=0.407moles[/tex] of [tex]AlCl_3[/tex]
Thus 0.407 moles of aluminum chloride could be produced from 11.0 g of aluminum.
6.How many molecules of carbon dioxide are in 400 grams of the substance?
Answer: 5.47x10^24 molecules
Explanation:
6.02214076x10^23 molecules CO2 = 44g
400g = (400/44)*6.02214076*10^23 = 5.47x10^24
According to the concept of Avogadro's number, there are 54.75 ×10²³ molecules of carbon dioxide are 400 grams of the substance.
What is Avogadro's number?Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number .Number of moles= 400/44=9.09 moles which is number of molecules =9.09×6.023×10²³= 54.75 ×10²³ .
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A ball thrown across a football field is an example of a(n)
I don't know what you mean by the question, but in science it is Newton's second law.
"The second law explains how the velocity of an object changes when it is subjected to an external force."
I hope this helped!+*♡
What relationship does Charles's law describe?
A. The relationship between temperature and volume
B. The relationship between moles and temperature
C. The relationship between pressure and volume
D. The relationship between volume and moles
SUBMIT
Answer: the relationship between temperature and volume
Explanation:
What is the concentration of a solution with a volume of 1.38 mL that contains 17.36
grams of ammonium sulfite [(NH4)2SO3)?
Answer:
C = 107.97 mol/L
Explanation:
Given data:
Volume of solution = 1.38 mL (1.38 mL× 1 L /1000 mL = 0.00138 L)
Mass of ammonium sulfite = 17.36 g
Concentration of solution =?
Solution:
We will calculate the number of moles of ammonium sulfite.
Number of moles = mass/molar mass
Number of moles = 17.36 g / 116.15 g/mol
Number of moles = 0.149 mol
Concentration:
C = n/V
C = concentration
n = number of moles of solute
v = volume in L
C = 0.149 mol / 0.00138 L
C = 107.97 mol/L
The wrist is ________________ to the hand.
Answer:
complimentary
Explanation:
Answer:
Proximal
Explanation:
3: Consider molecules of hydrogen (tiny ones) and oxygen (bigger ones) in a gas mixture. If they have the same average kinetic energy (they will at the same temperature), which molecules have the greatest average speed
Answer: Hydrogen molecules will have greatest average speed.
Explanation:
The formula for average speed is :
[tex]\mu_{av}={\sqrt{\frac{8RT}{\pi\times M}}}[/tex]
R = gas constant
T = temperature
M = Molecular Mass
Now putting all the values:
[tex]\frac{\nu_{H_2}}{\nu_{O_2}}=\sqrt{\frac{8RT}{\pi\times M_{H_2}}}/{\sqrt{\frac{8RT}{\pi\times M_{O_2}}}[/tex]
[tex]\frac{\nu_{H_2}}{\nu_{O_2}}=\sqrt{\frac{16}{2}}[/tex]
[tex]\frac{\nu_{av}_{H_2}}{\nu_{av}_{O_2}}=8[/tex]
Thus average speed of hydrogen is 8 times the average speed of oxygen. Thus hydrogen molecules will have greatest average speed
The food web above shows how energy moves through a lake environment. If a chemical company were to put a harmful chemical
that kills off all of the phytoplankton, which animal would be immediately affected?
)
A)
bacteria
B)
invertebrates
human
D)
prey fish
Answer:
Invertebrates than eventually everything would die
17. Which of the following
hydrocarbon undergo addition
reaction:
С3Н6
С2Н6
ОООО
С3Н8
CH4
Answer:
С3Н6.
Explanation:
Hello!
In this case, since addition reactions imply that a radical or some radicals are added to the parent chain, we notice that only unsaturated hydrocarbons are able to undergo addition whereas saturated ones undergo substitution reactions as they already have all the carbon bonds bonded to leaving groups.
In such a way, we can rule out C2H6, C3H8 and CH4 as they are all alkanes; therefore, only С3Н6 is able to undergo an addition reaction due to the C=C which is able to lose one of those bonds and allow an incoming radical to get included into the parent chain.
Best regards!
Calculate the moles of ammonia present in a 1.284 g sample if the molar mass of ammonia is 17.030 g/mol.
Answer:
The moles of ammonia present in a 1.284 g sample are 0.075.
Explanation:
Molar mass is the mass of one mole of a substance, which can be an element or a compound. If the molar mass of ammonia is 17,030 g / mol, then in 1 mole of ammonia there are 17,030 g.
So, in this case, the following rule of three can be applied: if by definition of molar mass in there are 17.030 g in 1 mole of ammonia, 1.284 g of ammonia in how many moles will it be?
[tex]moles=\frac{1.284 g*1 mole}{17.030 g}[/tex]
moles=0.075
The moles of ammonia present in a 1.284 g sample are 0.075.