Answer:
Thus, the element containing the greatest number of atoms is 12 g He. Thus, the correct option is (4) 12 g He. Note: The number of atoms of a compound is Avogadro's number for 1 mole of compound. The number 6.022×1023 is known as Avogadro's number.
Explanation:
(4)✔️ 12 g He
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iammallikaAnswer:
120gram I think so this is the answer if the answer is correct plz mark me as brainliest.
every action produces an equal and opposite -- ---------- when one object exterts a force on another object,the second object pushes back with the same amount of---------
someone knows the answer
In the SI system of units, the mole is one of seven base units. It is frequently used in chemical calculations. However, a mole of something is just a particular quantity of it. It is not a unit of measure in the way that meters, seconds, and kilograms are. Calculations performed with the number of moles of a substance could also be performed with the number of particles of a substance. Based on this information, do you think that the mole should be considered a base unit in the SI system? Explain why or why not.
The international system of units is known as SI and is a metric system. Mostly used as a system of measurement. It is used in science, technology, and nearly in every part of the country. The system includes coherent units known as derived units.
A mole is not a base unit or any property of the units. It can be used for physical and chemical comparison and hence the mole of substance can be performed with the number of particles of the substance.Hence the option B is correct.
Learn more about the frequently used in chemical calculations.
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How many grams of Br are in 345g of CaBr2?
Answer:
276g of Br are present
Explanation:
To solve this question we need to find the moles of CaBr2 using its molar mass -CaBr2: 199.89g/mol-. As 1 mole of CaBr2 contains 2 moles of Br we can find the moles of Br and its mass:
Moles CaBr2:
345g * (1mol/199.89g) = 1.7259 moles CaBr2
Moles Br:
1.7259 moles CaBr2 * (2mol Br / 1mol CaBr2) = 3.4519 moles Br
Mass Br -Molar mass: 79.904g/mol-
3.4519 moles Br * (79.904g/mol) = 276g of Br are present
NEED AN ANSWER ASAP!!! PLSSS
Compare and contrast an electrolytic cell with a voltaic cell. Provide one example where both are present in daily life.
Answer:
In both voltaic and electrolytic cells, oxidation occurs at the anode, while reduction occurs at the cathode. Thus, both these cells exhibit redox reactions. In both these cells, electrons flow from the anode to the cathode through the externally connected conductor.
Answer:
ELECTROLYTIC CELL
An electrochemical cell in which a non-spontaneous chemical reaction takes place when electric current is passed through the solution,is called an electrolytic cell.
EXAMPLE
Nelsons cell and Downs cell
VOLTAIC CELL OR GALVANIC CELL
The electrochemical cell in which a spontaneous chemical reaction takes place and generates electric current is called galvanic and voltaic cell.
EXAMPLE
Daniel cell
Explanation:
Find the mass in grams of 15.00 moles of AICI:
Answer:
937.5g
Explanation:
No of moles = mass ÷ molar mass
According to this question, there are 15moles of the compound; AlCl
Molar mass of AlCl = 27 + 35.5
= 62.5g/mol
Using n = m/M.M
15 = m/62.5
m = 15 × 62.5
m = 937.5g
According to Le Châtelier's principle, how will an increase in pressure affect a gaseous equilibrium system? O Shift it toward the products O Shift it toward the reactants Shift it toward the side with higher total mole concentration O Shift it toward the side with lower total mole concentration
Answer:
Shift it toward the side with lower total mole concentration
Explanation:
The reaction will shift in a direction that is less affected by stress, so that the pressure is reduced. This means that the reaction will change towards where there is fewer gas molecules (the fewer gas molecules, the smaller the pressure).
Answer:
A. Shift it toward the side with lower total mole concentration
Explanation:
If 14.7 cm3 of alcohol is present in 70 cm 3 of its aqueous solution, the percentage by volume of alcohol will be?
Answer: The percentage by volume of alcohol will be 21%.
Explanation:
Given: Volume of solute = 14.7 [tex]cm^{3}[/tex]
Volume of solvent = 70 [tex]cm^{3}[/tex]
Formula used to calculate percentage by volume is as follows.
[tex]Percentage volume = \frac{volume of solute}{volume of solvent} \times 100[/tex]
Substitute the values into above formula as follows.
[tex]Percentage volume = \frac{volume of solute}{volume of solvent} \times 100\\= \frac{14.7 cm^{3}}{70 cm^{3}} \times 100\\= 21 percent[/tex]
Thus, we can conclude that the percentage by volume of alcohol will be 21%.
The structure shown is an example of what kind of molecule?
A) Ether
B) Alkene
C) Polymer
D) Monomer
Answer:
i think its C polymer hope it helps
Question 2: Heat (5 points)
A. Describe the following heat equations, and identify the indicated variables.
i. Q = mcΔT; identify c. (1 point)
ii. Q = mLvapor; identify Lvapor. (1 point)
iii. Q = mLfusion; identify Lfusion. (1 point)
Answer:
(i) specific heat
(ii) latent heat of vaporization
(iii) latent heat of fusion
Explanation:
i. Q = mcΔT; identify c.
Here, Q is heat, m is the mass, c is the specific heat and ΔT is the change in temperature.
The amount of heat required to raise the temperature of substance of mass 1 kg by 1 degree C is known as the specific heat.
ii. Q = mLvapor; identify Lvapor
Here, Q is the heat, m is the mass and L is the latent heat of vaporization.
The amount of heat required to convert the 1 kg liquid into 1 kg vapor at constant temperature.
iii. Q = mLfusion; identify Lfusion
Here, Q is the heat, m is the mass and L is the latent heat of fusion.
Here, Q is the heat, m is the mass and L is the latent heat of vaporization.
The amount of heat required to convert the 1 kg solid into 1 kg liquid at constant temperature.
(i) c is the molar heat capacity of the substance.
(ii) Lvapor is the latent heat of evaporation of the substance
(iii) Lfusion is the latent heat of fusion of the substance
All the 3 equations fall under Calorimetry.
In all the equation Q is the amount of heat required.
(i) First equation represents the amount of heat required to raise the temperature of a substance of mass m.
Q = mcΔT
here c is the molar heat capacity of the substance and ΔT is the chnage in temperature.
(ii) Second equation represents the amount of heat required to convert a substance of mass m from liquid phase to vapour phase.
Q = mLvapor
here Lvapor is the latent heat of evaporation of the substance
during evaporation no change in temperature occurs.
(iii) Third equation represents the amount of heat required to convert a substance of mass m from solid phase to liquid phase.
Q = mLfusion
here Lfusion is the latent heat of fusion or melting of the substance
during fusion no change in temperature occurs.
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What dose science do
Explanation:
Science, any system of knowledge that is concerned with the physical world and its phenomena and that entails unbiased observations and systematic experimentation. In general, a science involves a pursuit of knowledge covering general truths or the operations of fundamental laws.
Heat is most closely related to which kind of energy?
O nuclear
electrical
thermal
chemical
Answer:
C thermal
Explanation:
How would an increased level of acetyl-CoA be expected to affect the pyruvate dehydrogenase reaction
Answer:
The pyruvate dehydrogenase kinase enzyme activity would increase, resulting in an inhibition of pyruvate dehydrogenase activity. ... An in vitro study shows that isocitrate dehydrogenase is activated in the citrate cycle.
Explanation:
Un medicamento corresponde a una disolución de "nafazolina" (sustancia activa) en agua purificada, en una concentración de 12% V/V. - EXPLICA cuánto soluto hay por cada 100mL del medicamento.
Answer:
12 mL
Explanation:
Según la pregunta;
V / V% concentración del fármaco = 12%
volumen de la solución = 100 ml
De;
V / V% = volumen de fármaco / volumen de solución
volumen de fármaco = V / V% × volumen de solución
volumen de fármaco = 12/100 × 100
= 12 mL
The reversible reaction, 4HCl(g) + Si (s) ⇌ SiCl4 (l) + 2H2 (g) , would be classified as a ______________ reaction.
exothermic
endothermic
homogeneous
heterogeneous
Answer:
endothermic
Explanation:
endothermic reactions absorb heat from their surroundings, in this reaction the reactants are gas and solid and the products are liquid and gas, implying heat was absorbed to turn a solid to a liquid.
The mass of a boy is 60 kg. Calculate his weight if the value of g is 9.8 ms2
Answer:
Weight = mass × gravitational
Weight = 60 kg × 9.8 ms²
= 588 N
Explanation:
hope it helps
Weight of the boy = Mass of the boy × g
= 60 × 9.8
= 588kgm/s²
= 588N
Stoichiometry - Chemistry
Answer:
C
Explanation:
in the option C when we rearrange it then it will he C3H6O2
Answer:
yes its C
Explanation:
correct me if iam wrong
thank you so much for putting all the answers in there
Answer:
[tex]\huge\color{cyan}{\colorbox{magenta}{Answer}}[/tex]
thank you
HELP ASAP!! PLEASE !!
Answer:
8,3, 7,7
Explanation:
.
Unlike a theory, a scientific law describes an observed pattern without attempting to _____ it.
explain
prove
test
verify
How were the elements in the first periodic table arranged? O A. In order of atomic number B. Alphabetically by element name C. In order of date of discovery O D. In order of atomic mass
Answer:
in order of their atomic mass
The first periodic table created by Mendeleev was based on the atomic masses of elements. Later Mosely modified it based on the atomic number.
What is periodic table ?Periodic table is the classification of all the known elements based on their atomic number. There are 118 elements in periodic table now. They are classified into different groups and periods.
Mendeleev was first to create periodic table for the easy classification of elements. He classified elements based on their atomic masses. At that time there were only 60-65 elements discovered.
Later Mosley modified it to modern periodic table based on the increasing order of atomic number of elements. Therefore, the first arrangement was based on atomic masses.
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An enclosed vessel contains 2.5g of 9b nitrogen and 13.3g of chlorine at s.T.P. Of What will be the partial pressure of the Il nitrogen if the temperature is raised to b 180C
Answer:
0.535 atm
Explanation:
Since the volume of the tank is constant, we use Gay- Lussac's law to find the pressure at 180°C.
So, P₁/T₁ = P₂/T₂ where P₁ = pressure at S.T.P = 1 atm, T₁ = temperature at S.T.P = 273.15 K, P₂ = pressure of gas at 180 °C and T₂ = 180 °C = 273.15 + 180 K = 453.15 K
So, P₁/T₁ = P₂/T₂
P₂ = P₁T₂/T₁
Substituting the values of the variables into the equation, we have
P₂ = P₁T₂/T₁
P₂ = 1 atm × 453.15 K/273.15 K
P₂ = 1 atm × 1.66
P₂ = 1.66 atm
We now need to find the total number of moles of each gas present
number of moles of nitrogen = mass of nitrogen, m/molar mass of nitrogen molecule M
n = m/M
m = 2.5 g and M = 2 × atomic mass of nitrogen (since it is diatomic) = 2 × 14 g/mol = 28 g/mol
So, n = 2.5 g/28 g/mol
n = 0.089 mol
number of moles of chlorine, n' = mass of chlorine, m'/molar mass of chlorine molecule M'
n' = m'/M'
m' = 13.3 g and M = 2 × atomic mass of chlorine (since it is diatomic) = 2 × 35.5 g/mol = 71 g/mol
So, n' = 13.3 g/71 g/mol
n' = 0.187 mol
So, the total number of moles of gas present is n" = n + n' = 0.089 mol + 0.187 mol = 0.276 mol
So, the partial pressure due to nitrogen gas, P = mole fraction of nitrogen × pressure of gas at 180 °C
P = n/n" × P₂
P = 0.089 mol/0.276 mol × 1.66 atm
P = 0.322 × 1.66 atm
P = 0.535 atm
Select the correct answer.
0.22 M
HCI
Unknown
LiOH
What is the concentration of the base (LIOH) in this titration?
1.0 ml
0.5 ml
Initial
burette
reading
Final
burette
reading
13.3 ml
18.5 ml
OA
0.16 M
ОВ.
0.15 M
OC. 0.22 M
OD
18 M
O E
0.5 M
Daset
Answer:
=0.15M
Explanation:
To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.
Using the stoichiometric coefficient, mole ratio 1:1.
This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL
See the explanation from the image I have shared with you for calculations.
solve this question please! it have 3 options which one of them is correct option
Answer:
I think option two (2) is the correct answer
What are the concentrations of hydronium and hydroxide ions in a solution with pH 2.6?
hey hi mate
wassup
answer is 4
explanation To calculate the pH of a solution, use the equation
p
H
=
−
log
[
H
3
O
+
]
Since we are given the hydronium ion (
H
3
O
+
) concentration of the solution, we can plug this value into the formula.
p
H
=
−
log
[
1.00
×
10
−
4
M
]
p
H
=
4
The pH of this solution is 4.
Added notes:
p
H
=
p
H
3
O
+
because hydrogen ions attach to water molecules for form hydronium ions.
Some other key things to remember for pH calculations include:
pH + pOH = 14
pH = -log[
H
+
]
pOH = -log[
O
H
−
]
[
H
+
]
=
10
−
p
H
[
O
H
−
]
=
10
−
p
O
H
If calcium carbonate (Cacos) decomposes. What would the product of the reaction be?
Answer:
CaO
Explanation:
Group 2 Carbonates decompose to form oxides of the Group 2 element and Carbon dioxide
Glycerin, , is a nonvolatile liquid. What is the vapor pressure of a solution made by adding glycerin to at
Complete question is;
Glycerin, C3H8O3, is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 164 g glycerin to 338 mL H2O at 39.8°C?
The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.0992 g/cm³
Answer:
28 torr
Explanation:
Let's first find the number of moles of water in 338 mL.
Molar mass of water = 18 g/mole
Formula for number of moles = mass/molar mass.
Mass = density × volume = 0.0992 × 338 = 33.5296 g
Thus;
Number of moles = 33.5296/18 = 1.863 moles.
Let's use the same procedure to find the Number of moles of glycerine.
Molar mass of glycerine from online values = 92.1 g/mol
Thus;
n_glycerine = (mass)/92.1
We have mass and density as 164 g and 0.0992 g/cm³ respectively.
n_glycerine = 164/92.1
n_glycerine = 1.78
Total moles of solution = 1.863 + 1.78 = 3.643 moles
We are told that The vapor pressure of pure water at 39.8°C is 54.74 torr
Thus, since water dominates, then vapour pressure of solution = (1.863/3.643) × 54.74 ≈ 28 torr
Which of the following statements regarding the movement of electrons during cellular respiration is true?
A. Electrons tend to move away from O2.
B. O2 is reduced when it accepts electrons and forms water.
C. The electrons release large amounts of energy each time they are transferred from one molecule to another.
D. O2 is eventually oxidized by the electrons to form water.
Answer:
B. O2 is reduced when it accepts electrons and forms water.
Explanation:
During cellular respiration water is formed when oxygen receives electrons and picks up protons at the conclusion of the electron transport chain. The electron transport chain will stop functioning if there isn't enough oxygen to receive electrons (for example, because a person isn't breathing in enough oxygen), and ATP will no longer be created by chemiosmosis. Cells can't carry out the reactions they need to function if they don't even have enough ATP, and they may perish after a long period of time.
A gas has density 2.41 g/liter at 25°C and 770 mm Hg. Calculate it's molecular mass (R = 0.0821 L atm.mol-1K-1
Answer:
Explanation:
Given : Density - 2.41 g/liter
Temperature - 25° C
Pressure : 770 mm Hg
R = 0.0821 L atm mol-¹K-¹
Find : Molecular mass of gas
Solution : Ideal gas equation with respect to density will be : PM = dRT. In the formula, P is pressure, M is molecular mass, d is density, R is gas constant and T is temperature.
Keeping the values in equation-
Pressure : 770 mm Hg = 1 atm
Temperature : 273 + 25 = 298 K
M = dRT/P
M = (2.41*0.0821*298)/1
M = 58.96 gram/mol
Thus, the molecular mass of gas is 58.96 gram/mol.
As a pure element the oxidation number of zinc is ________, but in compounds such as ZnCO3 its oxidation number is ________. Group of answer choices
Answer:
0, +2
Explanation:
As a pure element, any element or simple compound has an oxidation number of 0. This makes it a lot easier, and can be applied for almost any element or compound that uses one atom, like F2, O3, Zn, Fe, etc. However, in compounds, Zinc's oxidation number tends to be +2, and this is just a rule that I memorized when I learned this topic. Please let me know if you still need help and I hope you understood!
As a pure element, the oxidation number of zinc is zero, but in compounds such as [tex]ZnCO_3\\[/tex] its oxidation number is +2.
What is the oxidation number?Oxidation number also called oxidation state, is the total number of electrons that an atom either gains or loses in order to form a chemical bond with another atom.
As a pure element, any element or simple compound has an oxidation number of 0. This makes it a lot easier and can be applied for almost any element or compound that uses one atom, like [tex]F_2[/tex], [tex]O_3[/tex], Zn, Fe, etc.
However, in compounds, Zinc's oxidation number tends to be +2.
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Write two points of differences between complete and incomplete combustion?
Answer:
In complete combustion, there is a sufficient supply of oxygen which is able to react with the burning hydrocarbon allowing the reaction products H2O and CO2 to be formed. In incomplete combustion there is a lack of oxygen so when heat is applied carbon monoxide is released.
I hope this will help you......
