Answer:
0.074 moles
Explanation:
For every mole (of any element), there are 6.022 x 10^23 atoms.
There are 4.45 x 10^22 atoms of iron.
To find the moles we divide the number of atoms by Avogadro's number
4.45 x 10^22 / 6.022 x 10^23 = 0.0738957
Don't forget sig figs
Answer:
[tex]\boxed {\boxed {\sf 0.0739 \ mol \ Fe}}[/tex]
Explanation:
We are asked to convert a number of iron atoms to moles of iron.
We will use Avogadro's Number for this, which is 6.022 × 10²³. This is the number of particles (atoms, molecules, formula units, etc.) in 1 mole of a substance. For this problem, the particles are atoms of iron. There are 6.022 ×10²³ atoms of iron in 1 mole of iron.
We will also use dimensional analysis to solve this problem. To do this, we use ratios. Set up a ratio using the underlined information.
[tex]\frac {6.022 \times 10^{23} \ atoms \ Fe} {1 \ mol \ Fe}[/tex]
Since we are converting 4.45 × 10²² atoms of iron to moles, we multiply the ratio by that value.
[tex]4.45 \ \times 10^{22} \ atoms \ Fe *\frac {6.022 \times 10^{23} \ atoms \ Fe} {1 \ mol \ Fe}[/tex]
Flip the ratio. The value is the same, but it allows us to cancel the units of atoms of iron.
[tex]4.45 \ \times 10^{22} \ atoms \ Fe *\frac {1 \ mol \ Fe}{6.022 \times 10^{23} \ atoms \ Fe}[/tex]
[tex]4.45 \ \times 10^{22} *\frac {1 \ mol \ Fe}{6.022 \times 10^{23}}[/tex]
Condense into 1 fraction.
[tex]\frac {4.45 \ \times 10^{22} }{6.022 \times 10^{23}} \ mol \ Fe[/tex]
[tex]0.07389571571 \ mol \ Fe[/tex]
The original measurement of atoms ( 4.45 × 10²²) has 3 significaint figures, so our answer must have the same. For the number we calculated, that is the ten-thousandths place. The 9 to the right of this place (0.07389571571) tells us to round the 8 up to a 9.
[tex]0.0739 \ mol \ Fe[/tex]
There are approximately 0.0739 moles of iron in 4.45 × 10²² atoms of iron.
81.5 g of metal was heated from 11 degrees Celsius to 69 degrees Celsius. If 6739 joules of heat energy were used, what is the specific heat capacity of the metal?
Answer:
the metal become red hot
what is meant by density
Answer:
The degree of compactness of a substance
Balance the redox reaction Al(s) + MnO4^- (aq) --> MnO2 (s) + Al(OH)4^- (aq) in aqueous basic solution
Answer:
Al + MnO4- + 2H2O → Al(OH)4- + MnO2
Explanation:
First of all, we out down the skeleton equation;
Al + MnO4- → MnO2 + Al(OH)4-
Secondly, we write the oxidation and reduction equation in basic medium;
Oxidation half equation:Al + 4H2O + 4OH- → Al(OH)4- + 4H2O + 3e-
Reduction half equation:MnO4- + 4H2O + 3e- → MnO2 + 2H2O + 4OH-
Thirdly, we add the two half reactions together to obtain:
Al + MnO4- + 8H2O + 4OH- + 3e- → Al(OH)4- + MnO2 + 6H2O + 3e- + 4OH-
Lastly, cancel out species that occur on both sides of the reaction equation;
Al + MnO4- + 8H2O→ Al(OH)4- + MnO2 + 6H2O
The simplified equation now becomes;
Al + MnO4- + 2H2O → Al(OH)4- + MnO2
How is the compound NH3 classified?
A. As a salt
B. As a base
C. As an acid
D. As ionic
Answer:
B
Explanation:
Ammonia is considered a base as it's pH is 11
Answer from Gauthmath
The compound NH3 (Ammonia) can be classified as a weak Base. Below you can learn more about Ammonia.
What is Ammonia (NH3)?Ammonia is a chemical compound which is derived from the combination of Nitrogen and Hydrogen. It is denoted by the chemical formula NH3.
Ammonia is a base and when it reacts with acids to gives out salts. Physically, It is a colorless gas with a distinct characteristic of a pungent smell.
Learn more about Ammonia at https://brainly.com/question/14445062
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Two flasks are connected by a closed valve. One contains gas particles and the other contains a vacuum. If the valve is opened such that the particles move until they fill both flasks, the process by which the particles can reconvene entirely in one of the flasks is:
Answer: The process by which the particles can reconvene entirely in one of the flasks is: NONSPONTANEOUS.
Explanation:
The spontaneity of a process can affect the distribution of energy and matter within the system. Different chemical or physical processes have the natural tendency to occur in one direction under a given set of conditions. For example:
--> when water is pour down a hill it naturally flows down but it requires outside energy maybe from a water pump to flow up the hill and ,
--> during an iron rust, iron that is exposed to atmosphere will corrode, but rust is not converted to iron without intentional chemical treatment.
Therefore, a spontaneous process is one that occurs naturally under certain conditions. While a NONSPONTANEOUS process, on the other hand, will not take place unless it is initiated by the continual input of energy from an outside source. A process that is spontaneous in one direction under a particular set of conditions is nonspontaneous in the REVERSE direction.
From the two flasks that where connected through a valve, once the valve was opened, the gas spontaneously becomes evenly distributed between the flasks. To reverse this, it would require an external energy making the reconvening of the particles back to the first flask a NONSPONTANEOUS PROCESS .
An ion of a single pure element always has an oxidation number of ________.
A. None of these
B. magnitude equal to its atomic number
C. 1
D. 0
Answer:
0
Explanation:
pure elements will always possess an oxidation number of 0, regardless of their charge.
Answer:
D.) 0
Explanation:
I got it correct on founders edtell
lution: What is the molarity of 245 g of H, SO4 dissolved in 1.00 L of solution?
Answer:
Cm = n/V
n(H2SO4) = 245/98 = 2.5 mol
Cm(H2SO4) = 2.5/1 = 2.5 M
Explanation:
Ammonium phosphate NH43PO4 is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid H3PO4 with ammonia NH3. What mass of ammonium phosphate is produced by the reaction of 5.5g of phosphoric acid
Answer:
8.3 g
Explanation:
Step 1: Write the balanced equation
H₃PO₄ + 3 NH₃ ⇒ (NH₄)₃PO₄
Step 2: Calculate the moles corresponding to 5.5 g of H₃PO₄
The molar mass of H₃PO₄ is 97.99 g/mol.
5.5 g × 1 mol/97.99 g = 0.056 mol
Step 3: Calculate the moles of (NH₄)₃PO₄ produced
The molar ratio of H₃PO₄ to (NH₄)₃PO₄is 1:1. The moles of (NH₄)₃PO₄ produced are 1/1 × 0.056 mol = 0.056 mol.
Step 4: Calculate the mass corresponding to 0.056 moles of (NH₄)₃PO₄
The molar mass of (NH₄)₃PO₄ is 149.09 g/mol.
0.056 mol × 149.09 g/mol = 8.3 g
All of the following are characteristics of metals except: Group of answer choices good conductors of heat malleable ductile often lustrous tend to gain electrons in chemical reactions
Answer:
Hence the correct option is the last option that is tends to gain electrons in chemical reactions to become anions.
Explanation:
Metals tend to donate electrons in chemical reactions to become cations.
What is a reaction rate?
Answer:
A reaction is the time that is required for a chemical reaction to go essential to completion
Để xác định hàm lượng Cu trong hợp kim Cu-Zn người ta làm như sau: Hòa
tan hoàn toàn 2,068g mẫu hợp kim Cu-Zn trong lượng dư axit HNO3, thu được dung
dịch X. Đun đuổi axit dư, điều chỉnh tới pH 3 thu được 100mL dung dịch Y. Lấy
10mL dung dịch Y, thêm KI dư, rồi chuẩn độ dung dịch tạo thành bằng dung dịch
Na2S2O3 0,1M thì thấy hết 15,0 mL. Viết các phương trình phản ứng xảy ra. Tính
hàm lượng Cu trong mẫu hợp kim trên.
Many important analgesic compounds are derived from simple aromatic starting materials.
a. True
b. False
A 2.00-mol sample of hydrogen gas is heated at constant pressure from 294 K to 414 K. (a) Calculate the energy transferred to the gas by heat. kJ (b) Calculate the increase in its internal energy. kJ (c) Calculate the work done on the gas. kJ
Answer:
a) The energy transferred is 6.91 kJ
b) The internal energy is 4.90 kJ
c) The work done on the gas is - 2.01 kJ
Explanation:
Step 1: Data given
Number of moles of hydrogen gas = 2.00 moles
Pressure = constant
Temperature is heated from 294 K to 414 K
Molar heat capacity of hydrogen gas = 28.8 J/mol*K
Step 2: Calculate the energy transferred to the gas by heat.
Q = n* Cp * ΔT
⇒with Q =the energy transferred
⇒with n = the number of moles = 2.00 moles
⇒with Cp = the Molar heat capacity of hydrogen gas = 28.8 J/mol*K
⇒ with ΔT = Temperature 2 - Temperature 1 = 414 - 294 = 120K
Q = 2.00 * 28.8 * 120
Q = 6912 J = 6.91 kJ
Step 3: Calculate the increase in its internal energy.
ΔEint = n*Cv*ΔT
⇒with ΔEint = the increase in its internal energy.
⇒with n = the number of moles = 2.00 moles
⇒with Cv = The constant volume = 20.4 J/mol*K
⇒with ΔT = Temperature 2 - Temperature 1 = 414 - 294 = 120K
ΔEint = 2.00 * 20.4 * 120
ΔEint =4896 J = 4.90 kJ
Step 4: Calculate the work done on the gas.
Work done on the gas = -Q + ΔEint
W = -6.91 kJ + 4.90 kJ
W = -2.01 kJ
1.Q= {n: 7 <n<31}, list the members of the set Q
Q={x:x[tex]\epsilon[/tex]n,7<n<31}
[tex]\\ \sf\longmapsto Q=\left\{8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\right\}[/tex]
You can write it like this too
[tex]\\ \sf\longmapsto Q=\left\{8,9......30,31\right\}[/tex]
How much heat energy is required to raise the temperature of 50g of bromine from 25°C to 30°C? [Specific heat capacity of bromine = 0.226 J/(g °C]
Answer:
56.5J
Explanation:
To find the heat energy required use the formula for the specific heat capacity which is
c=quantity of heat/mass×change in temperature
in this question c is 0.226j/g,the mass is 50g and the change in temperature is 30-25=5
therefore
0.226=Q/50×5
Q=0.226×250
=56.5J
I hope this helps
How many grams of glucose are needed to prepare 144.3 mL of a 1.4%(m/v) glucose solution?
Answer:
2.0202 grams
Explanation:
1.4% (m/v) glucose solution means: 1.4g glucose/100mL solution.
so ?g glucose = 144.3 mL soln
Now apply the conversion factor, and you have:
?g glucose = 144.3mL soln x (1.4g glucose/100mL soln).
so you have (144.3x1.4/100) g glucose= 2.0202 grams
State what would be observed when the following pairs of reagents are mixed in a test tube.
C6H2COOH and Na2CO3(aq)
(ii) CH3CH2CH2OH and KMnO4 /H
(iii) CH3CH2OH and CH3COOH + conc. H2SO4 (iv) CH3CH = CHCH3 and Br2 /H2O
Answer:
(i). C6H2COOH and Na2CO3(aq)
observation: Bubbles of a colourless gas (carbon dioxide gas)
(ii) CH3CH2CH2OH and KMnO4 /H
observation: The orange solution turns green.
[This is because oxidation of propanol to propanoic acid occurs]
(iii) CH3CH2OH and CH3COOH + conc. H2SO4
observation: A sweet fruity smell is formed.
[This is because an ester, diethylether is formed]
(iv) CH3CH = CHCH3 and Br2 /H2O
observation: a brown solution is formed.
Which of the following would have the lowest kinetic energy?
a) Gaseous water
b) Boiling water
c) Liquid water
d) nSolid water
Answer:
d) Solid water
Explanation:
because it's particles are more fixed together ( least apart ), so their mobility and conductivity is very low hence lowest kinetic energy.
Answer:
d. Solid water
Explanation:
example ice
Why must beta particles be used to detect leaks in a pipe?
Why must beta particles be used to detect leaks in a pipe?
A. Beta particles will not be absorbed by the soil like gamma radiation, but won't pass through the pipe before reaching the leak like alpha radiation would.
B. Beta particles will not cause an electrical discharge like alpha particles when they interact with the metal pipe, or contaminate the water like gamma radiation.
C. Beta particles are not used, only alpha particles are used because they are not harmful to humans.
D. Beta particles will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak like gamma radiation would.
Should be D, because alpha particles are absorbed by soil and gamma isn't
Beta particles will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak.
What is Beta particle?This type of particle is a high-speed electron and is derived from the process of beta decay.
It is used to detect leaks in pipe because it will not be absorbed by the soil like alpha particles, but won't pass through the pipe before reaching the leak like gamma radiation would.
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The big bang theory suggests that the origin of the universe began with
that exploded and
expanded.
Answer:
Yes?
Explanation:
If you're asking whether or not that's true, then the Big Bang suggests a way the universe might have formed, so yes it's true
Answer:
A star
Explanation:
Given the following reaction:
CO (g) + 2 H2(g) <==> CH3OH (g)
In an experiment, 0.42 mol of CO and 0.42 mol of H2 were placed in a 1.00-L reaction vessel. At equilibrium, there were 0.29 mol of CO remaining. Keq at the temperature of the experiment is ________.
A) 2.80
B) 0.357
C) 14.5
D) 17.5
E) none of the above
Answer:
Option D. 17.5
Explanation:
Equiibrium is: CO + 2H₂ ⇄ CH₃OH
1 mol of CO is in equibrium with 2 moles of hydrogen in order to make, methanol.
Initially we have 0.42 moles of CO and 0.42 moles of H₂
If 0.29 moles of CO remained, (0.42 - 0.29) = 0.13 moles have reacted.
So in the equilibrium we may have:
0.29 moles of CO, and (0.42 - 0.13 . 2) = 0.16 moles of H₂
Ratio is 1:2, if 0.13 moles of CO haved reacted, (0.13 . 2) moles have reacted of hydrogen
Finally 0.13 moles of methanol, are found after the equilibrium reach the end.
Let's make expression for KC: [Methanol] / [CO] . [Hydrogen]²
0.13 / (0.29 . 0.16²)
Kc = 17.5
Too many objects inside a laboratory fume hood can disrupt the airflow and possibly compromise you safety. Which of the following are considered best practices in the use of a laboratory fume hood?
a. Open the sash as much as possible
b. Work at least 25 cm inside the hood
c. Use fast, quick movements to limit your exposure
d. Place objects to one side—work on other side
e. Use a raised along the back of the hood
Best practices for fume hoods: work 25 cm inside, organize items to one side, use raised ledge; avoid open sash and quick movements.
Laboratory fume hoods must be used safely. Workers should operate at least 25 cm within the hood to preserve ventilation and avoid dangerous chemicals. Place things on one side of the hood to preserve ventilation and prevent clogging.
A raised ledge on the rear of the hood prevents things from falling in and impeding airflow. Avoid fully opening the sash to maintain ventilation and containment. Fast, rapid motions can interrupt airflow, so prevent them. These practises guarantee the fume hood contains harmful compounds, making the lab safer. Therefore, option (B), (D) and (E) are correct.
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What makes it possible
for a vascular plant to
be a long distance from
a water source?
A. long leaves
B. flowers
C. long roots
D. long stems
Answer:
I think long roots
Explanation:
What do you predict the chemical formula for the compound formed between calcium and sulfur?
Answer:
calcium donates two vanence electrons to sulfur atom to form Ca2+ ion and an S2+ - ion
Methane (CH4) is the major component of natural gas. 40.0 grams of methane were placed in a commercial calorimeter and subjected to a combustion reaction. The reaction released 2800 kJ of energy.
1. Compare this energy value to the energy values of paraffin and isopropanol. Is methane a good choice as a fuel?
Based on comparison of energy produced per kilogram, a given mass of methane produces more energy than similar masses of either paraffin or isopropanol, therefore;
Methane is a good choice as a fuel
The reason for the above comparison conclusion is as follows:
The given information:
The details of the combustion of the methane gas, CH₄, are as follows;
The mass of the methane gas placed in the calorimeter, m = 40.0 g
The amount of heat released from the combustion of the 40.0 grams of methane = 2,800 kJ
The data from online resources of paraffin and isopropanol includes
1. The energy value of paraffin = 46 MJ/kg
The energy value of isopropanol = 33.6 MJ/kg
The energy produced from 1 kilogram of methane gas is given as follows;
40.0 g of methane gas produces 2,800 kJ of energy, therefore;
1 kg = 1,000 g of methane gas will produce, 2,800kJ/(40.0 g) × 1,000 g = 70,000,000 J
Therefore;
1 kg of methane produces 70,000,000 J = 70 MJ of energy
Therefore, energy produced from methane = 70 MJ/kg
Given that methane produces more than twice the amount of energy that
is produced from similar mass of isopropanol and more than one and half
times the amount of energy that is produced from the same mass of
paraffin, methane is a good choice as a fuel for energy
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A compound with a molecular weight of about 64.47 g/mol was found to be 18.63 % of C, 1.56 % of H, 24.82 % of O, and 54.99 % of Cl by mass. Determine the molecular formula and draw the Lewis structure showing an accurate 3-D perspective. *Show your calculations
Answer:
See detailed explanation.
Explanation:
Hey there!
In this case, according to the given information, it turns out possible for us to solve this problem by firstly calculating the moles of each element, assuming those percentages are masses, so that we divide by their molar masses:
[tex]C=\frac{18.63}{12.01}=1.55\\\\H=\frac{1.56}{1.01} =1.55\\\\O=\frac{24.82}{16.00}=1.55\\\\Cl=\frac{54.99}{35.45}=1.55[/tex]
Then, we divide all of them by 1.55 to realize the empirical formula is:
[tex]CHOCl[/tex]
Whose molar mass is 64.47 g/mol, and therefore, since the molar mass of these two is the same, we infer the molecular formula is also CHOCl.
The Lewis structure is shown on the attached document, whereas, the central atom is C and it does complete its octet as well as both O and Cl.
Regards!
Uhm cell parts and functions
A cell is the structural and fundamental unit of life. The study of cells from its basic structure to the functions of every cell organelle is called Cell Biology. Robert Hooke was the first Biologist who discovered cells
two types of cell
1) Prokaryotes
2) Eukaryotes
Characteristics of Cells
1) Cells provide structure and support to the body of an organism.
2) The cell interior is organised into different individual organelles surrounded by a separate membrane.
3) The nucleus (major organelle) holds genetic information necessary for reproduction and cell growth
[tex]hope \: its \: helpful \: to \: you \: please \: mark \: me \: a \: brainliest[/tex]
A cell is defined as the fundamental, structural and functional unit of all life.
have a great day
God bless you
Suppose a 250.mL flask is filled with 1.7mol of H2 and 0.90mol of I2. The following reaction becomes possible:
+H2gI2g 2HIg
The equilibrium constant K for this reaction is 5.51 at the temperature of the flask.
Calculate the equilibrium molarity of I2. Round your answer to two decimal places.
Explanation:
here's the answer. I just plug the expression into my calculator and find the intercept to avoid the quadratic formula
Please help chemistry ASAP
Will give brainly
Answer:
B
Explanation:
^^^^Changes in state of matter are ALWAYS changes.
Answer:
physical
Explanation:
The change in the state of matter is always physical change, because it can be done with physical processes.
