Given :
12.9 mol of Au.
To Find :
How many atoms are in 12.9 moles Au.
Solution :
We know, 1 mol of any element/molecules contains [tex]6.022\times 10^{23}\ atoms/mol[/tex].
Number of atoms in 12.9 moles of Au is :
[tex]n = 12.9 \times 6.022\times 10^{23}\ atoms\\\\n = 7.77\times 10^{24}\ atoms[/tex]
Therefore, number of atoms in 12.9 moles of Au is [tex]7.77\times 10^{24}\ atoms[/tex].
Hence, this is the required solution.
Answer:
amy what happen to your old account and the answer is c
Explanation:
Chemistry of Life Practice Active 8 1 What type of organic compound is used for building cell parts?
Answer:
Carbohydrates
Explanation:
What two options are homogeneous mixture
Answer:
vinegar and soap
Explanation:
Answer:
vinegar and soap
Explanation: just took the test
I NEED HELP ASAP PLEASE I BEG
with what?..................
explain what happens to temperature and energy as molecules move from gas to liquid to solid
Answer and Explanation:
As the temperature of the substances increases, the average energy of the molecules increases, and average energy of attraction between the molecules decreases consequently intermolecular spacing between the molecules increases. As a result, a substance change in succession from gas to liquid to solid.
Describe the bodys first line of defense
Answer:
The main function of the immune system is to provide immunity to the body. Immunity is the body's ability to protect itself from the pathogens it is exposed to. Immunity depends on the body's ability to differentiate between things that belong in the body and those that do not. The immune system's first line of defense includes physical and chemical barriers that are always ready and prepared to defend the body from infection.
The skin acts as a barrier against pathogens. Some structures of the first line of defense include the skin, mouth, eyes, ears, nose, and stomach. The skin produces sweat and oil that work together to keep pathogens from the entering the body. Saliva and tears contain substances the can destroy pathogens. The ears and the stomach help fight pathogens.The ears produce ear wax that prevent pathogens from entering the ears. The stomach produces a liquid the kills pathogens.
Mucus is produce by the nose, lungs, throat, and stomach. Mucus traps pathogens. Mucus also prevent pathogens from getting into deep tissues. Anyway, the very first line of defense against any invasion of the human body is a set of physical barriers between the inside of the body and the outer world.
*my notes from edge2020*
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Please help me on question #2 please please really need help due today at 9:00pm please
Most of the mass in an atom is found in the...?
7.46 - A 0.0500-mol sample of a nutrient substance is burned in a bomb calorimeter containing 2.00 x 10g H20. If the formula weight of this nutrient substance is 114 g/mol, what is the fuel value (in nutritional Cal) if the temperature of the water increased 5.70C?
Answer:
[tex]200\frac{kcal}{g}[/tex]
Explanation:
Hello!
In this case, for this calorimetry problem, since the combustion 0.0500 mol of the nutrient increase the temperature of water by 5.70 °C, we can notice that the heat lost by the nutrient is gained by water in order to write:
[tex]Q_{nutrient}=-Q_{water}[/tex]
Which can be also written as:
[tex]Q_{nutrient}=-m_{water}C_{water}\Delta T_{water}\\\\Q_{nutrient}=-200 g*4.184\frac{J}{g\°C}*5.70\°C\\\\Q_{nutrient}=4769.8 J[/tex]
Thus, in terms of the grams of the nutrient:
[tex]m_{nutrient}=0.0500mol*\frac{114g}{1mol}=5.70g[/tex]
The fuel value in nutritional Cal (kcal/g) turns out:
[tex]Fuel \ Value=\frac{-4.7698kJ}{5.70g}*\frac{1kcal}{4.184kJ}=200\frac{kcal}{g}[/tex]
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If 0.0806 mol CaCl2 is dissolved in water to make a 0.490 M solution, what is the volume of the solution?
Answer:
0.16 L
Explanation:
From the question given above, the following data were obtained:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity is simply defined as the mole of solute per unit litre of the solution. Mathematically, it is expressed as:
Molarity = mole /Volume
With the above formula, we can obtain the volume of the solution as illustrated below:
Mole = 0.0806 mole
Molarity = 0.490 M
Volume =?
Molarity = mole /Volume
0.490 = 0.0806/volume
Cross multiply
0.490 × volume = 0.0806
Divide both side by 0.490
Volume = 0.0806 / 0.490
Volume of solution = 0.16 L
Thus, the volume of the solution is 0.16 L.
A solution is a mixture of solute in the solvent. The volume of the solution is 0.16 L.
What is a solution?A solution is a mixture of solute in the solvent.
An example of a solution is a mixture of salt in water.
Given,
Moles = 0.0806 mol [tex]\rm CaCl_2[/tex]
Molarity = 0.490 M
To find: the volume of the solution
[tex]Molarity = \dfrac{n}{V}[/tex]
Putting the values
[tex]0.490 M = \dfrac{ 0.0806}{V}\\\\0.490 M \times V = 0.0806\\\\Divide\; both\;side\; with\; 0.490\\\\V= \dfrac{ 0.0806}{0.490}=0.16 L[/tex]
Thus, the volume so the solution is 0.16 l.
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The noble gases can be found in group/period ____
Answer:
group 18
Explanation:
The noble gases (Group 18) are located in the far right of the periodic table and were previously referred to as the "inert gases" due to the fact that their filled valence shells (octets) make them extremely nonreactive
Answer:group 18
Explanation
The ingredients of a soup include
1,500 grams of water, 350 grams of vegetables, and 210 grams of meat. What is the total mass of the soup?
Answer:
sopas
Explanation:
lagyan mo ng condense
There is a golden role of solubility, polar solute dissolve in polar solvent and non polar solute dissolve in non polar solvent. Therefore, the total mass of the soup is 2,060gram.
What is solution?Solutions are a homogeneous mixture of two or more substances. A solution is a homogeneous mixture of solvent and solute molecules. Solvent is a substance that is in large amount in solution. solute is the substance which is in small amount in a solution. There are two types of mixture that is homogeneous and heterogeneous. Solution is a homogeneous solution.
mass of soup= mass of water+ mass of vegetables + mass of meat
mass of water=1,500 grams
mass of vegetables= 350 grams
mass of meat=210 grams
substituting all the values in the above equation, we get
mass of soup= 1,500 grams+ 350 grams + 210 grams
= 2,060gram
Therefore, the total mass of the soup is 2,060gram.
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Sulfite is similar to hydroxide in its behavior as a ligand: most sulfites are insoluble in water, but excess sulfite can result in the formation of a complex ion. Write the two equilibrium reactions of sulfite with the copper(II) ion that show this behavior.
Answer:
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
Explanation:
A ligand may be defined as a molecule or an ion or that binds to the central metal atom in order to form a more coordination complex. Sulfite is one such ligand and it behaves similarly as hydroxide as a ligand.
Now, according to the question, when we react copper with sulfite ion, it forms copper sulfite. The equation is
[tex]$Cu_2+(SO_3)^2 \rightleftharpoons CuSO_3 \ (insoluble)$[/tex]
Now when excess of the sulfite ion is used in the reaction, we get a complex formation, which is shown by
[tex]$Cu_2+2(SO_3)^2 \rightleftharpoons [Cu(SO_3)_2]_2 \ (soluble)$[/tex]
The way the sulfite reacts is quite similar to hydroxide ion where they form a complex ion when hydroxide ion in excess is used in the reaction with metal cation.
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Rules:
Label the section of the roller coaster where the kinetic or potential energy is.
Answer:c
Explanation:
it’s gained kinetic from the gravitational potential energy at the top
How many different principal quantum numbers can be found in the ground-state electron configuration of nickel?A) 2.B) 3.C) 4.D) 5.E) 6.
Answer:
C) 4.
Explanation:
Hello!
In this case, since the electron configuration of nickel at its ground-state, considering 28 as its atomic number and the number of electrons it has in one atom, is:
[tex]Ni^{28}:1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^8[/tex]
We can see it has four energy levels, 1, 2, 3 and 4, which are related to the following principal quantum number, that describes the energy of an electron in the atom and its most probable distance with respect to the nucleus.
Therefore, nickel has C) 4 different principal quantum numbers.
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The freezing point of a solution the freezing point of the pure solvent
Answer:
This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur.
Explanation:
Answer:
Freezing Point Depression. The freezing point of a solution is less than the freezing point of the pure solvent. This means that a solution must be cooled to a lower temperature than the pure solvent in order for freezing to occur
What is the concentration of chloride ions in a solution that contains 0.375 g of aluminum chloride in 15.0 mL of solution?
Answer:
0.561 M
Explanation:
Step 1: Given data
Mass of aluminum chloride (m): 0.375 gMolar mass of aluminum chloride (M): 133.34 g/molVolume of the solution (V): 15.0 mLStep 2: Calculate the molar concentration of aluminum chloride (C)
We will use the following expression.
[tex]C = \frac{m}{M \times V(L) } = \frac{0.375g}{133.34 g/mol \times 0.0150L } = 0.187M[/tex]
Step 3: Write the reaction of dissociation of aluminum chloride
AlCl₃(aq) ⇒ Al³⁺(aq) + 3 Cl⁻(aq)
Step 4: Calculate the concentration of chloride ions
The molar ratio of AlCl₃ to Cl⁻ is 1:3. The concentration of Cl⁻ is 3/1 × 0.187 M = 0.561 M
given that the only known ionic charges of lead are pb(ii) and pb(iv), how can you explain the existence of the pb2o3 salt
Answer:
See Explanation
Explanation:
Pb2O3 is better formulated as PbO.PbO2. It is actually a mixture of the two oxides of lead, lead II oxide and lead IV oxide.
This implies that this compound Pb2O3 (sometimes called lead sesquioxide) is a mixture of the oxides of lead in its two known oxidation states +II and +IV.
Hence Pb2O3 contains PbO and PbO2 units.
Is iron man made or natural
Answer:
Iron is natural. Paper is man-made
Explanation:
Answer:
iron
Explanation:
The reaction between iron(II) oxide and carbon monoxide produces iron and carbon dioxide. How many moles of iron can be obtained when 1.50 mol FeO reacts with an excess of CO ?
FeO+CO⟶Fe+CO2
Answer:
1.5 moles of Fe produced.
Explanation:
Given data:
Moles of FeO react = 1.50 mol
Moles of iron produced = ?
Solution:
Chemical equation:
FeO + CO → Fe + CO₂
Now we will compare the moles of ironoxide with iron.
FeO : Fe
1 : 1
1.5 : 1.5
Thus from 1.5 moles of FeO 1.5 moles of Fe are produced.
1.5 moles of Fe can be obtained when 1.50 mol of FeO reacts with an excess
of CO
Moles of FeO reacted = 1.50 mol
Moles of iron produced = ? mol
The chemical equation is given as
FeO + CO → Fe + CO₂
Comparisons of FeO and Fe show they are in the ratio 1 : 1
FeO : Fe
1.5 : 1.5
which translates to the number of moles being equal
Therefore, 1.5 moles of FeO 1.5 moles of Fe are produced.
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How many moles of CO are produced when 1.8 moles C reacts?
Express your answer using two significat figures.
5C(s) + 2SO2(g) => CS2(l) +4CO(g)
Answer:
1.44mole of CO
Explanation:
The reaction equation is given as:
5C + 2SO₂ → CS₂ + 4CO
We check to see if the expression is balanced and it is so;
Now;
Given;
1.8mole of C reacted; how many moles of CO are produced;
From the balanced reaction equation:
5 mole of C is expected to produce 4 mole of CO
1.8 mole of C will then produce [tex]\frac{4 x 1.8}{5}[/tex] = 1.44mole of CO
Calculate the volume in milliliters of 1.57 M potassium hydroxide that contains 10.3 g of solute.
Answer:
[tex]V = 0.117 \ L[/tex]
General Formulas and Concepts:
Chem
Reading a Periodic TableWriting compounds and polyatomic ionsMolarity = moles of solute / liters of solutionExplanation:
Step 1: Define
1.57 M KOH (potassium hydroxide)
10.3 g KOH
Step 2: Define conversions
Molar Mass of K - 39.10 g/mol
Molar Mass of O - 16.00 g/mol
Molar Mass of H - 1.01 g/mol
Molar Mass of KOH - 39.10 + 16.00 + 1.01 = 56.11 g/mol
Step 3: Convert
[tex]10.3 \ g \ KOH(\frac{1 \ mol \ KOH}{56.11 \ g \ KOH} )[/tex] = 0.183568 mol KOH
Step 4: Solve for Volume
Substitute: [tex]1.57 \ M=\frac{0.183568 \ mol}{x \ L}[/tex]Move x: [tex]x1.57 \ M=0.183568 \ mol[/tex]Isolate x: [tex]x=\frac{0.183568 \ mol}{1.57 \ M}[/tex]Evaluate: [tex]x=0.116922 \ L[/tex]Step 5: Check
We are given 3 sig figs. Follow sig fig rules.
[tex]0.116922 \ L \approx 0.117 \ L[/tex]
A sample of 6.44 g of napthalene (C10H8) is dissolved in 80.1 g of benzene (C6H6). Calculate the percent by mass of napthalene in this solution.
Answer:
7.44%
Explanation:
[tex]\frac{6.44}{6.44+80.1} *100=7.44[/tex]
Some organizations are buying sections of forest. Once purchased, these sections will never be cut down. What is most likely the main reason for protecting these sections of forest? A Cause the extinction of undesirable animal species, B Prevent these trees from reproducing too fast, C Maintain the diversity of the living environment. D Crovide more land for agricultural purposes.
Answer:
I think is C
Explanation:
'Cause the questions says "these sections will Never cut down", so that means is proctecting the environment
Examples of solutions can be:
O A. a solid dissolved in a liquid
O B. gas mixed with a liquid
O C. liquid mixed with a liquid
OD. all of the the above
Answer:
B. gas mixed with a liquid
Explanation:
because:
A. a solid can't dissolve in a liquid.
C. two liquids mixed isn't a solution
D. Not All of the above for sure.
Examples of solutions can be all of the above. The correct option is D.
What is a solution?A solution is made when a solute is mixed with a solvent. The solution can be a liquid, solid, or gas. The solution is made when the solute is fully mixed with the solvent. The solute is the substance that gets mixed, and the solvent is the base in which the solute gets dissolved.
So, a solid dissolved in a liquid, gas mixed with a liquid, or a liquid mixed with a liquid, the energy statement is true for a solution.
Examples of a solution are sugar dissolved in water when water mix with soda and state gets mixed with water or another gas.
Thus, the correct options are D. all of the the above.
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For the following reaction at equilibrium SO3(g) + NO(g) = SO2(g) + NO2(g)It is found that [SO2] = 0.70 M and [NO] = 1.20 M. Calculate the equilibrium constant for the readction knowing that the initial concentration were [SO3] = 2.55 M and [NO] = 1.90 M.
Answer:
[tex]K=0.14[/tex]
Explanation:
Hello!
In this case, for the undergoing chemical reaction, we can write the equilibrium expression via:
[tex]K=\frac{[SO_2][NO_2]}{[SO_3][NO]}[/tex]
Whereas the equilibrium concentration of both SO3 and NO are 2.55 M and 1.90 M respectively, it means that the extent of reaction [tex]x[/tex] is:
[tex]x=1.90M-1.20M=0.7M[/tex]
Because the equilibrium expression in terms of the reaction extent is:
[tex]K=\frac{x*x}{([SO_3]_0-x)([NO]_0-x)}[/tex]
It means that the concentration of SO3, NO, SO2 and NO2 at equilibrium are:
[tex][SO_3]=2.55M-0.70M=1.85M[/tex]
[tex][NO]=1.20M[/tex]
[tex][SO_2]=0.70M[/tex]
[tex][NO_2]=0.70M[/tex]
Thus, the equilibrium constant for such reaction is:
[tex]K=\frac{0.70*0.70}{1.85*1.90}\\\\K=0.14[/tex]
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It is possible for gases in the atmosphere to change the behavior of energy on earth. Agree or disagree
Answer:
I agree
Explanation:
because the sunlight passes through the atmosphere and is absorbed by earth's surface.
The green house gases in the atmosphere can change the behavior of energy on earth. Thus i agree with this statement.
What is green house effect?The green house effect is defined as a process by which the radiations from the sun are absorbed by the green house gases like methane, Chloro fluoro carbons and not reflected back into the space. This makes the surface as insulator and prevents it from freezing.
Due to the increased level of green house gases, the temperature of the earth increases considerably and thereby causes global warming, depletion of ozone layer, smog and air pollution, etc.
It is the natural green house effect which affect the behaviour of heat energy radiated by the sun. The green house gases never let the radiations escape from the earth and increase the surface temperature of earth. This leads to global warming.
Thus green house gases affects the solar energy.
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How many grams of oxygen gas will be produced when 2.50 moles of potassium chlorate is decomposed?
Answer:
[tex]m_{O_2}=120gO_2[/tex]
Explanation:
Hello!
In this case, since the decomposition of potassium chlorate is:
[tex]2KClO_3\rightarrow 2KCl+3O_2[/tex]
We can see a 2:3 mole ratio between potassium chlorate and oxygen (molar mass 32.0 g/mol), thus, via stoichiometry, we compute the mass of oxygen that are produced by the decomposition of 2.50 moles of this reactant:
[tex]m_{O_2}=2.50molKClO_3*\frac{3molO_2}{2molKClO_3} *\frac{32.0gO_2}{1molO_2}\\\\m_{O_2}=120gO_2[/tex]
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How does one determine a percent composition from an empirical
formula?
A. Divide the atomic mass of the element by its subscript and
multiply by 100%
O B. Divide the mass of the compound by the atomic mass of
the element and multiply by 100%
O C. Divide the subscript of the element by the mass of the
element and multiply by 100%
O D. Divide the total mass of each element by the mass of the
compound and multiply by 100%
The way one determines a percent composition from an empirical formula is to divide the total mass of each element by the mass of the compound and multiply by 100%.
What is empirical formula?Empirical formula is a notation that indicates the ratios of the various elements present in a compound, without regard to the actual numbers.
The empirical formula of a compound is the simplest ratio that can exist between the constituent elements of a compound.
However, the percent composition of a compound can be determined by dividing the total mass of each element by the mass of the compound and multiply by 100%.
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An isotope of the element fluorine has 9 protons and 10 neutrons. What is the name of this isotope?
fluorine
Answer:
fluorine atom
Explanation:
Identify the necessary parts to build a calorimeter. Select one or more:________ A. Cover. B. An interior paper cup. C. Thermometer. D. An interior styrofoam cup. E. An exterior paper cup An exterior styrofoam cup Conductivity probe.
Answer:
Explanation:
A calorimeter is an instrument used for measuring the heat of reactions and heat capacity. A calorimeter should contain an insulating cover, a thermometer, styrofoam cups (you could have that both on the inside and the outside in the case of a styrofoam calorimeter) and you could also have a conductivity probe (in the form of ignition wires and bulb).
A calorimeter is the analytical device used to measure the heat of the reaction. The construction of calorimeter requires cover, paper cup, thermometer, styrofoam cup, and conductivity probe.
How to build a calorimeter?In a chemical reaction, the amount of heat released or absorbed by the reaction helps in the analysis of various parameters. The calorimeter measures the heat of the reaction.
The construction of a calorimeter requires:
Paper can for the filling of water.Cover to stop the loss of heatStyrofoam cup to allow the reactionThermometer to measure the change in temperatureConductivity probe to allow the transfer of heat energyLearn more about calorimeter, here:
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