Answer:
Heat energy is transferred to cooler objects to reduce the temperature of those objects.
Explanation:
The fourth option is not correct.
A correct way of writing it would be : " Heat energy is transferred from cooler objects to reduce the temperature of those objects.". When an object loses heat energy, its temperature reduces. Conversely, when an object receives heat energy, its temperature increases.
how many moles of hydrogen are needed to produce 8 moles of methane CH4? C + H2-> CH4
Answer:
20 mol H₂
General Formulas and Concepts:
Chem
StoichiometryExplanation:
Step 1: Define
RxN: C + H₂ → CH₄
8 moles CH₄
Step 2: Balance RxN
C + 2H₂ → CH₄
Step 3: Stoichiometry
[tex]8 \ mol \ CH_4(\frac{2 \ mol \ H_2}{1 \ mol \ CH_4} )[/tex] = 16 mol H₂
Step 4: Check
We are given 1 sig fig. Follow sig fig rules.
16 mol H₂ ≈ 20 mol H₂
Select the sentences in the paragraph that explain only the dark lines that are produced in the absorption spectra. Select all that apply.
A light is shown through a cold, dilute gas. Over time, excited atoms revert to their original lower energy state. Photons emitted travel in different directions that the original photon. Gaps are produced in the light spectra that correspond to wavelengths of absorbed photons. Dark lines in an absorption spectrum of light can be seen when the gas lies between the light source and observer.
Answer:
Gaps are produced in the light spectra that correspond to wavelengths of absorbed photons.
Explanation:
When electrons in atoms absorb energy, they move from a lower energy level to a higher energy level. With time, they revert to the their original energy state emitting a photon of light of appropriate wavelength.
The absorbed photons do not show up in the spectrum. They appear as dark lines in the spectrum. Hence, the absorption spectrum is the exact inverse of the emission spectrum. The dark lines in the spectrum indicates that the colors that ought to occupied those points there have been absorbed.
Select True or False: A mixture made from 10 mL of 1 M HCl and 20 mL of 1 M CH3COONa would be classified as a buffer solution.
Answer:
True.
Explanation:
There are three ways to make a buffer.
a. Generating a solution of a weak acid and its conjugate base.
b. Adding to a solution of a weak acid a certain quantity of
strong base, so that the acid remains in excess.
c. adding a limited amount to a conjugate base solution
of strong acid so that the base remains in excess.
We are in c, in this situation.
How do you calculate, pH? We apply Henderson Hasselbach.
pH = pka + log (mmoles base - mmoles acid)/ mmoles acid
pH = pKa + log ((20 ml . 1 M - 1 ml . 10M) / 10 mmoles
pH = 4.76 + log 1 → 4.76 ⇒ pH = pKa
Use the periodic table to match each of the following element symbols to its name, atomic mass, or atomic number. (3 points)
1.
Se
2.
S
3.
Sn
a.
Tin
b.
78.971 u (atomic mass)
c.
16 (atomic number)
Answer:
Tin I thunk
Explanation:
I think
Answer:
sn = tin
se = 78.971 u (atomic mass)
s = 16 (atomic number)
which part of earth absorbs the most sunlight?
A oceans
b soil
c atmosphere
d rivers and lakes
Answer:
atmosphere
Explanation:
The atmosphere absorbs the most in light because the atmosphere surrounds our planet
Answer:
c
Explanation:
What is the pH of a solution in which [H 3O +] = 3.8 × 10 -8 M?
Answer:
The answer is 7.42Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ { H_3O}^{+}][/tex]
From the question we have
[tex]pH = - log(3.8 \times {10}^{ - 8} ) \\ = 7.420216...[/tex]
We have the final answer as
7.42Hope this helps you
Does it matter which of the two sp3sp3 hybrid orbitals are used to hold the two nonbonding electron pairs
Answer:
No. All four hybrids are equivalent and the angles between them are all the same, so we can use any of the two to hold the nonbonding pairs.
Explanation:
Orbital hybridization has been the combination of the atomic orbitals for the formation of a new hybrid. No, it does not matter which orbitals are used to hold the nonbonding electron pairs.
What are hybrid orbitals?Hybrid orbitals are said to be formed by the mixing of the atomic orbitals with different energy and geometrical shape that allows the understanding of the atomic bonding and molecular geometry of the compounds.
It includes sp, sp², sp³, sp³d, and sp³d² which have various arrangements, including linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral. The hybrid orbitals are formed by the combination and overlapping of the s and p orbital.
It does not matter which sp³ orbital holds the two non-bonding electron pairs as all four hybrids have been known to have equivalent angles between them so it will not matter which hybrid has the non-bonded electrons in them.
Therefore, it will not matter which two sp³ hybrid holds the electron pairs that are not involved in bonding.
Learn more about orbital hybridization, here:
https://brainly.com/question/16251845
#SPJ6
the molar ratio of cucl2 to Al should be
Answer:
1) The chemical equation is:
Al + CuCl2 ---> Cu + AlCl3
2) You have to balance the equation to state the coefficients:
2Al + 3CuCl2 ---> 3Cu + 2Al Cl3
3) Now the coefficients tell you the molar ratios.
2 mol Al : 3 mol CuCl2 : 3 mol Cu : 2 mol AlCl3
4) The molar ratio of CuCl2 to Al is:
3 mol Cu Cl2 / 2 mol Al = 3/2 = 1.5
Explanation:
according to the law of energy conservation, the total amount of energy is constant, then why does the chemical energy in electric cells got used up?
Answer:
The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another.
Explanation:
This means that a system always has the same amount of energy unless it's added from the outside. is the total internal energy of a system.
A gas with a volume of 525 mL at a temperature of -25°C is heated to 175°C.
What is the new volume, in milliliters, of the gas if pressure and number of moles
are held constant?
Answer:
Volume V2 = 948.13 ml
Explanation:
Given:
Volume V1 = 525 ml
Temperature T1 = -25°C + 273.15
Volume V2 = ?
Temperature T1 = 175°C + 273.15
Computation:
V1 / T1 = V2 / T2
525 / [-25°C + 273.15] = V2 / [175°C + 273.15]
Volume V2 = 948.13 ml
The new volume, in milliliters, of the gas is 948 L
From the question,
We are to determine the new volume of the gas.
From Charles' law which states that the volume of a fixed mass of gas is directly proportional to the temperature (in Kelvin) provided that the pressure remains constant.
That is,
V ∝ T
Then,
V = kT
Therefore, we can write that
[tex]\frac{V_{1} }{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]
Where [tex]V_{1}[/tex] is the initial volume
[tex]T_{1}[/tex] is the initial temperature
[tex]V_{2}[/tex] is the final volume
and [tex]T_{2}[/tex] is the final temperature
From the given information,
[tex]V_{1} = 525 \ mL[/tex]
[tex]T_{1} = -25 ^{\circ}C = -25 + 273.15 \ K = 248.15 \ K[/tex]
[tex]T_{2} = 175 ^{\circ} C = 175 +273.15 \ K =448.15 \ K[/tex]
Putting the values into the formula, we get
[tex]\frac{525}{248.15} = \frac{V_{2} }{448.15}[/tex]
∴ [tex]V_{2} = \frac{525 \times 448.15}{248.15}[/tex]
[tex]V_{2} = \frac{235278.75}{248.15}[/tex]
[tex]V_{2} = 948.13 \ L[/tex]
V₂ ≅ 948 L
Hence, the new volume, in milliliters, of the gas is 948 L
Learn more here: https://brainly.com/question/12717895
Cuando realizamos la "Estructura de
Puntos de Lewis" ¿Qué es lo que se
utiliza para su representación? *
Answer:
Electrones de valencia.
Explanation:
¡Hola!
En este caso, dado en química se conocen las estructuras de Lewis como representaciones gráficas de como los elementos están enlazados entre sí, debemos tener en cuenta que estos enlaces se forman entre los electrones de valenciam, los cuales son utilizados para su representación. Se sabe que los electrones de valencia son representados con puntos alrededor del elemento a través de puntos que se unen entre sí y son el número de electrons en la capa más externa de los elementos en cuestión; por ejemplo, cloro tiene 7 electrones de valencia, azufre tiene 6, hidrogeno 1, carbono 4 y así sucesivamente.
¡Saludos!
de, it
this is a
your
Sample Response: This is a chemical change
because new substances are formed with different
properties and identities.
What did you include in your response? Check all that
apply
rmed with
This is a chemical change.
New substances are formed.
The properties and identities of the original
substances are changed.
If u click on all of them it gives u an A+ and doesn’t even read what u wrote. So u never really have to try hard on the writing parts just tell them u included them all
Answer:An image will not be formed.
Rays do not converge to or diverge from a common point.
/select all that apply
Explanation:
A 0.700 g unknown mixture with CaCl2 reacts with aqueous sodium phosphate to give 0.425 g Ca3(PO4)2. Show calculation for the percentage CaCl2?
The percentage CaCl₂ : 65.14%
Further explanationA reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction
3CaCl₂+2Na₃PO₄⇒Ca₃(PO₄)₂ + 6NaCl
mol Ca₃(PO₄)₂(MW=310.18 g/mol) :
[tex]\tt \dfrac{0.425}{310.18}=0.00137[/tex]
mol ratio CaCl₂ : Ca₃(PO₄)₂ = 3 : 1, so mol CaCl₂ :
[tex]\tt \dfrac{3}{1}\times 0.00137=0.00411[/tex]
mass CaCl₂ (MW=110.98 g/mol) :
[tex]\tt 0.00411\times 110.98=0.456~g[/tex]
The percentage CaCl₂ :
[tex]\tt \%CaCl_2~in~mixture=\dfrac{0.456}{0.7}\times 100\%=65.14\%[/tex]
. Calculate the entropy change associated with the isothermal compression of 0.720 mol of an ideal gas from 24.32 L to 3.90 L.
Answer:
[tex]$\Delta S = -10.95 \ \frac{J}{K}$[/tex]
Explanation:
Given :
Number of mole, n = 0.720 mol
Initial volume, [tex]$V_1$[/tex] = 24. 32 L
Final volume, [tex]$V_2$[/tex] = 3.90 L
We know entropy change,
[tex]$\Delta S = c_V\ln \left(\frac{T_2}{T_1}\right) + n R \ln \left(\frac{V_2}{V_1}\right)$[/tex]
For isothermal compression temperature constant,
[tex]$\Delta S = n R \ln \left(\frac{V_2}{V_1}\right)$[/tex]
[tex]$\Delta S = 0.720 \times 8.314 \times \ln \left(\frac{3.90}{24.32}\right)$[/tex]
[tex]$\Delta S = -10.95 \ JK^{-1}$[/tex]
[tex]$\Delta S = -10.95 \ \frac{J}{K}$[/tex]
Bonds are broken in an____
reaction.
a). Endergonic
b). Exergonic
Answer:
Reactions where chemical bonds are broken, releasing the energy in those bonds, are often exergonic reactions.
Explanation:
Reactions where chemical bonds are broken, releasing the energy in those bonds, are often exergonic reactions. These reactions where chemicals are broken down are called “catabolism” – the destructive part of metabolism. By contrast, reactions where chemical bonds are formed are often endergonic.
Na₂S
Naming ionic compound
Answer:
Sodium Sulfide
Explanation:
I looked it up
. A 20.0 % by mass solution of phosphoric acid (H3PO4) in water has a density of 1.114 g/mL at 20°C. What is the molarity of this solution?
The molar mass of phosphoric acid (H3PO4) is 97.99 g.
Answer:
2.273M
Explanation:
What is the definition of molarity.
M = mols/L. So that's what we need to determine.
How much does a L weigh? That's
1.114 g/mL x 1000 mL = 1114 grams. Simple enough, eh?
How much of that 1114 g is H3PO4. It says it is 20% by mass, therefore, 1114 g x 0.20 = 222.8 g.
How many mols are there in 222.8 g H3PO4? That's mools = grams/molar mass = 222.8/98 = 2.273 mols.
The definition of M is what? M = mols/L. And you have 2.273 mol/L; that must be the molarity.
The formula is
density g/mL x 1000 mL x mass% x (1/molar mass) = M
1.114 x 1000 x 0.20 x (1/98) = 2.273 M.
What may happen to the human body when exposed to an infectious agent?
A. When infectious agents get into the human body, your body responds by functioning normally.
B. When infectious agents get into the human body, the body gets a surge of energy, causing a slight increase in body temperature, and you feel great.
C. When infectious agents get into the human body, your body responds by raising the core body temperature, causing a fever.
D.Nothing happens when the human body is exposed to an infectious agent.
Answer:
when infectious agents get into the human body your body responds by raising the core body temperature causing a fever
The answer is C it will raise your body temp and cause a fever
(2 points) How many grams of K2SO4 are present in 25.0 mL of 7.00 % (m/v) solution?
Show your work. No work = no credit.
Mass of K₂SO₄ : 1.75 g
Further explanationThe concentration of a substance can be expressed in several quantities such as moles, percent (%) weight/volume,), molarity, molality, parts per million (ppm) or mole fraction. The concentration shows the amount of solute in a unit of the amount of solvent.
volume of solution = 25 ml
% (m/v)=7%
mass of K₂SO₄ :
[tex]\tt \%m/v=\dfrac{mass~of~solute}{volume~of~solution}\times 100\%\\\\7\%=\dfrac{mass~K_SO_4}{25}\times 100\%\\\\mass~K_2SO_4=7\times 25\div 100=1.75~g[/tex]
Choose all the answers that apply.
Which of the following statements are true?
OThe space between neurons is called a synapse.
OThe nucleus of a neuron is located in the cell body.
O Practice can increase the speed of neuron signal transfer.
0Axons carry messages toward the cell body.
o Electrical impulses in neurons go two ways.
Answer:
I think this the right answer maybe, the space between neurons is called a synapse. The nucleus of a neuron is located in the cell body. Axons carry messages toward the cell body. These are the true ones I think.
Explanation:
Answer:
1,2, and 4
Explanation:
2. Calculate the new molanty of a solution formed when 20 ml of water is added to 100 ml of
0.2M NaOH
Answer:
New molarity = M₂ = 0.167 M
Explanation:
Given data:
New molarity = M₂ = ?
Final volume = V₂ = 100mL + 20 mL = 120 mL
Initial volume =M₁ = 100 mL
Initial molarity =V₁ = 0.2 M
Solution:
M₁V₁ = M₂V₂
0.2 M × 100 mL = M₂ × 100 mL
M₂ = 0.2 M × 100 mL/120 mL
M₂ = 20 M.mL/120 mL
M₂ = 0.167 M
How many moles of H20 are required to react completely with 7.30 moles of NO2?
3NO2(g) + H200 +
NO(g) + 2HNO3(aq) A
1.86 mol
2.19 mol
2.43 mol
O 6.12 mol
O 7.30 mol
Answer:
2.43 moles of water are require.
Explanation:
Number of moles of water required = ?
Number of moles of NO₂ available = 7.30 mol
Solution:
Chemical equation:
3NO₂ + H₂O → NO + 2HNO₃
now we will compare the moles of NO₂ with H₂O.
NO₂ : H₂O
3 : 1
7.30 : 1/3×7.30 = 2.43 mol
Give two everyday examples of the thermal energy of a substance being decreased
Answer:
An example of the thermal energy of a substance being decreased is with our food. With the thermal energy of food being decreased it is easier for foods to be eaten comfortably without any damage to the tongue or alimentary canal.
Another good example is in the handling of hot objects in the home. Thermal energy decrease in objects such as iron, pots etc helps to prevent serious burns and injuries.
Answer:
Water turning into ice
juice frozen to make popsicles
Explanation:
When something goes from liquid to a solid, that is a process called freezing. When a object loses thermal energy the particles move slower forming a solid.
1. How many moles of water molecules are there in 39 grams of Chlorine?
2. How many molecules are there in 39 grams of Gold?
Answer:
1. There is no moles of water in 39g of chlorine.
2. 1.19x10²³ molecules of Au.
Explanation:
First, we need to remember that molar mass of a compound represents the mass of 1 mole (6.022x10²³ molecules) of molecules.
Molar mass of Chlorine, Cl₂ is 70.9g/mol
Molar mass of gold, Au, is 197g/mol
1. Moles of 39g of Cl₂ are:
39g Cl₂ * (1mol / 70.9g) = 0.55 moles moles of chlorine
But there is no moles of water in 39g of chlorine.
2. First, moles of Au are:
39g Au * (1mol / 197g) = 0.198 moles Au.
Molecules are:
0.198 moles Au * (6.022x10²³ molecules / 1 mol) =
1.19x10²³ molecules of AuAtom a and atom b have the same number of protons and neutrons but they do not have the same number of electrons. What statement describes the atoms
The given question is incomplete. The complete question is:
Atom a and atom b have the same number of protons and neutrons but they do not have the same number of electrons. What statement describes the atoms?
The atoms have the same chemical symbol.
The atoms have the same charge.
The atoms have different atomic numbers.
The atoms have different atomic masses.
Answer: The atoms have the same chemical symbol.
Explanation:
Atomic number is equal to the number of protons for any neutral or charged specie and is specific to a particular element. Thus two elements having same atomic number will have same chemical symbols.
Mass number is the sum of number of protons and the number of neutrons.
As atoms a nd b have same protons and neutrons , they will have same atomic number and same mass number. But as the number of electrons are different , the charge on them will be different.
Thus the correct statement is the atoms have the same chemical symbol.
Answer:
They have the same chemical symbol
Explanation:
Answer the question plssss
Answer: warmer because its an exothermic reaction.
Explanation: the passage states as the products form thermal energy is absorbed thermal means heat also carbon dioxide creates bubbles
16.025 has how many sig fig
Answer:
5
Explanation:
Significant figures:
The given measurement have four significant figures 1234.
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.03 in this number only one significant figure present which is 3.
Zero between the non zero digits are consider significant like 104 consist of three significant figures.
The zeros at the right side e.g 2400 are also significant. There are four significant figures are present.
In given measurement:
16.025 there are 5 significant figures 1,6,0,2,5
Consider a three-dimensional model of methane as seen here in two dimensions. If we use VSEPR theory to describe the geometry of a methane molecule we say its shape is. A) Linear. B) Tetrahedral. C)Trigonal Planar. D)Trigonal Bipyramidal
Answer:B
Explanation:
Tetrahedral I took the test
Answer:
B is the answer'
Explanation:
A chemist heats 34.10 g of nickel to 77.17 °C, then places the metal sample in the cup of water shown in the interactive.
Calculate the final temperature of the water. The specific heat of nickel is 0.444 J/g °C and the specific heat of water is
4.184 J/g °C.
Answer:
[tex]T_{eq}=27.97\°C[/tex]
Explanation:
Hello.
In this case, for equilibrium temperature problems, it is said that the heat balance allows us to notice how the hot substance heats up the cold substance until they reach the equilibrium temperature which is a temperature that remains constant upon time. Thus, since here the hot substance is the nickel and water gains that released heat by the nickel we can write:
[tex]Q_{Zn}=-Q_{water}[/tex]
Which can be written in terms of temperatures, masses and specific heats:
[tex]m_{Zn}C_{Zn}(T_{eq}-T_{Zn})=-m_{water}C_{water}(T_{eq}-T_{water})[/tex]
Thus, solving for the equilibrium temperature we write:
[tex]T_{eq}=\frac{m_{Zn}C_{Zn}T_{Zn}+m_{water}C_{water}T_{water}}{m_{Zn}C_{Zn}+m_{water}C_{water}}[/tex]
Now, plugging in the known data, considering the mass of water 64.00-4.00=60.00 g and its initial temperature, 25.00°C, we obtain:
[tex]T_{eq}=\frac{34.10g*0.444\frac{J}{g\°C}* 77.17\°C+60.0g*4.184\frac{J}{g\°C}*25.00\°C}{34.10g*0.444\frac{J}{g\°C}+60.0g*4.184\frac{J}{g\°C}}\\\\T_{eq}=27.97\°C[/tex]
Best regards!
The final temperature of water is required.
The final temperature of water is [tex]27.97^{\circ}\text{C}[/tex].
T = Equilibrium temperature
[tex]T_n[/tex] = Temperature of nickel = [tex](77.17^{\circ}\text{C}+273.15)\ \text{K}[/tex]
[tex]T_w[/tex] = Temperature of water = [tex](25^{\circ}\text{C}+273.15)\ \text{K}[/tex]
[tex]c_n[/tex] = Specific heat of nickel = [tex]0.444\ \text{J/g}^{\circ}\text{C}[/tex]
[tex]c_w[/tex] = Specific heat of water = [tex]4.184\ \text{J/g}^{\circ}\text{C}[/tex]
[tex]m_n[/tex] = Mass of nickel = 34.1 g
[tex]m_w[/tex] = Mass of water = 60 g
The heat balance of the system is given by
[tex]m_wc_w(T-T_w)=m_nc_n(T_n-T)\\\Rightarrow m_wc_wT-m_wc_wT_w=m_nc_nT_n-m_nc_nT\\\Rightarrow T=\dfrac{m_nc_nT_n+m_wc_wT_w}{m_wc_w+m_nc_n}\\\Rightarrow T=\dfrac{34.1\times 0.444\times 350.32+60\times 4.184\times 298.15}{60\times 4.184+34.1\times 0.444}\\\Rightarrow T=301.12\ \text{K}=301.12-273.15\\\Rightarrow T=27.97^{\circ}\text{C}[/tex]
The final temperature of water is [tex]27.97^{\circ}\text{C}[/tex].
Learn more:
https://brainly.com/question/19327113?referrer=searchResults
It can be seen that the three methyl groups in camphor and isoborneol show up as separate peaks, whereas those in borneol overlap to where they almost appear as a single peak. Based on your knowledge of chemical shift factors, explain why this is so?
Answer:
isoborneol and camphor both have methyl groups that have different shielding zones with -OH and -C=O groups respectively.
Explanation:
Using the knowledge of chemical shift we can see that out of the three methyl groups in isoborneol, there are two methyl groups that are not influenced by the chemical Influence of the -OH functional group while one of the methyl groups is influenced by the -OH functional group.
For Camphor, two out of the three methyl groups are in shielding zones of the Carbonyl group, -C=O. While the last of the three methyl groups is out of the shielding zones of Carbonyl group, -C=O.