Answer:
11 moles Al
Explanation:
To find the amount of moles, you need to use Avogadro's number to convert the atoms to moles. Since the value you were given has 2 significant figures, the final answer should also have 2 sig figs.
Avogadro's Number:
6.022 x 10²³ atoms = 1 mole
6.4 x 10²⁴ atoms Al 1 moles
---------------------------- x ------------------------------ = 10.6 moles Al
6.022 x 10²³ atoms
= 11 moles Al
Which of the following is true about homogeneous mixtures?
a) They consist of two or more phases.
b) They are always liquids.
c) They have compositions that never vary.
d) They are known as solutions.
Which of these statements are true? Select all that apply.
The Delta.Hf for Br2(I) is 0 kJ/mol.
The Delta.Hf for He(I) is 0 kJ/mol.
The Delta.Hf for Hg(I) is 0 kJ/mol.
The Delta.Hf for Cl2(g) is 0 kJ/mol.
The Delta.Hf for N2(I) is 0 kJ/mol.
The enthalpy of formation (ΔHf) of [tex]Br_2[/tex](g) at 1.00 atm and 298 K is 0 kJ/mol. Hence, option A is correct.
What does ΔHf mean?The standard enthalpy of formation is defined as the enthalpy change for creating one mole of a compound from elements in their standard states.
The enthalpy of formation (ΔHf) of [tex]Br_2[/tex] (g) at 1.00 atm and 298 K is 0 kJ/mol.
It is because the enthalpy of formation of the molecule is only 0 in its standard state and for bromine, the standard state at 298K is the liquid state.
Hence, option A is correct.
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Answer:
A: The Δ.Hf for Br2(I) is 0 kJ/mol.
C: The Δ.Hf for Hg(I) is 0 kJ/mol.
D: The Δ.Hf for Cl2(g) is 0 kJ/mol.
Explanation:
Which statement is true of magnets
The statement that is true about magnets is ''Similar poles of a magnet repel each other.''
What are the characteristics of magnet?All magnets have both north and south poles. Opposite poles attract each other, whereas the similar poles repel each other. When you rub a piece of iron along a magnet, this force creates a magnetic field.
So we can conclude that The statement that is true about magnets is ''Similar poles of a magnet repel each other.''
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differentiate between electrolytic and metallic conductors.
[tex] \\ [/tex]
ty! ~
Explanation:
Metallic conductors contain free electron for conduction of electricity and is a good conductor of heat and electricity
electrolytic conductors contain ions for conduction
The kind of
reproduction that requires two
parents is called
What’s the answer for 3 and 8 please answer as soon as Possible due tomorrow morning.
Answer:
fgrthrdfghgfgfhfdhfdh
Explanation:
fdhhfgdghhdfghdfhgfhgfgh
Which of the following is NOT an example of a tension force?
O tug of war
O towing a car
O magnets
O pulling a bucket from a well
↓
Answer:
Magnets
Explanation:
magnets donot require tension force
Please HELP!!!! Im stuck!
The enthalpy of the reaction, [tex]S_{(s)} + O_{2}_{(g)} \rightarrow SO_{2}_{(g)}[/tex], ΔH is -197 kJ.
What is the enthalpy change of the reaction?The enthalpy change of a reaction, ΔH, is the heat absorbed or given off when reactants form products for a given reaction.
The enthalpy change, ΔH, of the reaction given below:
[tex]S_{(s)} + O_{2}_{(g)} \rightarrow SO_{2}_{(g)}[/tex]
The enthalpy change is calculated from the intermediate reactions:
[tex]S_{(s)} + \frac{3}{2}\:O_{2}_{(g)} \rightarrow SO_{3}_{(g)} \:\Delta H_{1} = -395.2 \:kJ\\SO_{3}_{(g)}\rightarrow SO_{2}{(g)} + \frac{1}{2}O_{2}_{(g)} \:\Delta H_{2} = 198.2\:kJ[/tex]
ΔH = ΔH₁ + ΔH₂
ΔH = -395.2 + 198.2 kJ
ΔH = -197 kJ
Therefore, the enthalpy of the reaction, [tex]S_{(s)} + O_{2}_{(g)} \rightarrow SO_{2}_{(g)}[/tex], ΔH = -197 kJ.
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How do the valence electrons of an atom affect chemical reactions?
Answer:
Electrons of an atom can affect chemical reactions, because electrons have a negative charge, which can introduce a form of energy.
Balance this reaction.
CO +
H2 →
CH3OH
The temperature of 150 mL of water is 25°C. What must happen for the
temperature of the water to increase to 35°C?
A. Water must be removed to decrease the thermal energy.
OB. More water must be added to increase the thermal energy.
C. Thermal energy must be transferred to the water to increase the
average kinetic energy of the water molecules.
D. Thermal energy must be transferred from the water to decrease
the average kinetic energy of the water molecules.
What is the pH of a solution that has a [H+] = 0.010 mol/L?
Answer:
pH = 2
A 0.010 M solution of hydrochloric acid, HCl, has a molarity of 0.010 M. This means that [H+] = 1 x 10-2 M. The pH of this aqueous solution of H+ ions is pH = 2
hope this helps :3
A crate holds 20 boxes of sewing supplies. Each box contains 8 spools of thread. Each spool has 250 meters of thread wrapped around it. What length of thread is contained in a crate?
Answer: 40000
Explanation:
250*8=2,000
2000*20=40000
Which of the following is best described as an acid-base reaction?
O HNO3(aq) + NH3(aq) → NH4*(aq) + NO3(aq)
O P4(s) + 3OH (aq) + 3H3O(1)→ PH3(g) + 3H₂PO₂ (aq)
O Cu(s) + H₂S(g) → CuS(s) + H₂(g)
O 2H₂(g) + O2(g) → 2H₂O(l)
O 2KCIO3(aq) → 2KCI(s) + 302(g)
The reaction which represents an acid-base reaction is: HNO3(aq) + NH3(aq) → NH4*(aq) + NO3(aq).
What is an acid-base reaction?An acid-base reaction is a reaction in which a substance donate protons to another substance which then accepts the proton.
An acid-base reaction usually involves the formation of a salt.
From the given reactions, the acid-base reaction is given below:
HNO3(aq) + NH3(aq) → NH4*(aq) + NO3(aq)In the given reaction, HNO3 donates a proton and NH3 accepts the proton.
Therefore, the reaction which represents an acid-base reaction is: HNO3(aq) + NH3(aq) → NH4*(aq) + NO3(aq).
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Give the postional isomers of 2 halopropane
(CH3)2CH
Give the positional isomers of 2 halopropane
(CH3)2CH
answer:
is in file download it
when you eat food, where does digestion begin do physical and chemical changes happen in mouth how?
The process of digestion begins in the mouth with the intake of food. The teeth play an important role in masticating (chewing) or physically breaking food into smaller particles. The enzymes present in saliva also begin to chemically break down food.
Explanation:
#CarryOnLearningA certain chemical reaction telesales 24.7 kk/g of heat for each gram of reactant consumed
The mass of reactant that would produce 800 Joules of heat is equal to 800 J × (1 kJ/1000 J)/(24.7 kJ/g).
How to calculate the mass of reactant?In order to determine the mass of reactant that would produce 800 Joules of heat, we would set up a conversion equation as follows:
Note: 1 kJ is equal to 1000 Joules.
Conversion:
1 gram = 24.7 kJ
X gram = 800 Joules
Therefore, the mass of reactant that would produce 800 Joules of heat is given by:
Mass = Heat × (conversion factor/rate of heat)
Mass = 800 J × (1 kJ/1000 J)/(24.7 kJ/g).
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Complete Question:
A certain chemical reaction releases 24.7 kJ/g of heat for each gram of reactant consumed. How can you calculate what mass of reactant will produce 800 Joules of heat?
How many grams of Ca(OH)2 are needed to produce 500 ml of 1.66 M Ca(OH)2 solution?
61.5 grams of Ca(OH)2 are needed to produce 500 ml of 1.66 M Ca(OH)2 solution. Details about mass can be found below.
How to calculate mass?The mass of a substance can be calculated by multiplying the number
of moles of the substance by its molar mass.
However, in this question, the number of moles in 500 ml of 1.66 M Ca(OH)2 solution must be calculated first.
no of moles = 1.66M × 0.5L
no of moles = 0.83moles
molar mass of Ca(OH)2 = 74.093 g/mol
mass of Ca(OH)2 = 74.093 × 0.83 = 61.5g
Therefore, 61.5 grams of Ca(OH)2 are needed to produce 500 ml of 1.66 M Ca(OH)2 solution.
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20.0 g of bromic acid, HBrO3, is reacted with excess HBr.
HBrO3 (aq) + 5 HBr (aq) → 3 H2O (l) + 3 Br2 (aq)
What is the theoretical yield of Br2 for this reaction? Round your answer to the nearest gram.
After Rounding off The percentage yield is 64%
What is Percentage Yield ?It is the ratio of actual yield to theoretical yield multiplied by 100% .
It is given in the question
20.0 g of bromic acid, HBrO3, is reacted with excess HBr.
The reaction is
HBrO₃ (aq) + 5 HBr (aq) → 3 H₂O (l) + 3 Br₂ (aq)
Actual yield = 47.3 grams
Molecular weight of Bromic Acid is 128.91 gram
Moles of Bromic Acid = 20/128.91 = 0.155 mole
Mole fraction ratio of Bromic Acid to Bromine is 1 :3
Therefore for 0.155 mole of Bromic Acid 3 * 0.155 = 0.465 mole of Bromine is produced.
1 mole of Bromine = 159.8 grams of Bromine
0.465 of Bromine = 74.31 grams of Bromine
Percentage Yield = (47.3/74.31)*100 = 63.65 %
After Rounding off The percentage yield is 64% .
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Answer:
74g
Explanation:
The other person had said that the Percentage Yield = (47.3/74.31)*100 = 63.65 %
So, since to find the percent yield you have to divide the actual yield by the theoretical yield, I would assume the theoretical yield is 74.31g (74g if you round to the nearest gram)
48g of 02 produce how many grams of Al2O3
Taking into account the reaction stoichiometry, 102 grams of Al₂O₃ are formed when 48 grams of O₂ react.
Reaction stoichiometryIn first place, the balanced reaction is:
4 Al + 3 O₂ → 2 Al₂O₃
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
Al: 4 moles O₂: 3 molesAl₂O₃: 2 molesThe molar mass of the compounds is:
Al: 27 g/moleO₂: 32 g/moleAl₂O₃: 102 g/moleThen, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:
Al: 4 moles ×27 g/mole= 108 gramsO₂: 3 moles ×32 g/mole= 96 gramsAl₂O₃: 2 moles ×102 g/mole= 204 gramsMass of Al₂O₃ formedThe following rule of three can be applied: if by reaction stoichiometry 96 grams of O₂ form 204 grams of Al₂O₃, 48 grams of O₂ form how much mass of Al₂O₃?
[tex]mass of Al_{2} O_{3} =\frac{48 grams of O_{2} x204 grams of Al_{2} O_{3}}{96 grams of O_{2}}[/tex]
mass of Al₂O₃= 102 grams
Finally, 102 grams of Al₂O₃ are formed when 48 grams of O₂ react.
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Which type of fault would you
find at a divergent boundary?
A. normal fault - hanging wall moves down
relative to footwall
B. hanging fault - both walls hung up and do not
move
C. reverse fault - hanging wall moves up relative
to footwall
D. strike-slip fault - fault walls slide side by side
select the correct answer from each drop down menu how do you the freezing point and boiling point of a solution compare with those of us pure solvent? The freezing point of the solution is ___ and the boiling point is _____ than that of its pure solvent.
Explanation:
select the correct answer from each drp down
Every spring has an equilibrium position. Which statements describe a spring at its equilibrium position? Check all that apply.
The spring constant is zero.
The elastic potential energy is at a maximum.
The elastic potential energy is zero.
The displacement of the spring is at a maximum.
The net force acting on the spring is zero.
The statements describe a spring at its equilibrium position is the elastic potential energy is zero, the displacement of the spring is at a maximum and the net force acting on the spring is zero.
What is the equilibrium position?
A body is in equilibrium when the sum of all forces acting on it equals zero. According to Newton's First Law, when resulting from the laws that act on a body that remains in a state of restriction or in motion in its motion, it remains uniformly null.
In this case the only statements that match the definition of equilibrium position are:
The elastic potential energy is zero.The displacement of the spring is at a maximum.The net force acting on the spring is zero.See more about equilibrium position at brainly.com/question/10374921
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How many total atoms are there in one molecule of C145H293O168?
Answer:
606 atoms
Explanation:
Add the numbers 145 + 293 + 168
The direction of a reflected ray will always match its:
angle of incidence.
refracted ray.
diffused angle.
None of the choices are correct.
Answer:
angle of incidence.
Balance the equation by inserting coefficients as needed. equation: C 2 H 6 O+O 2 longrightarrow CO 2 +H 2 O
The coefficients needed to balance the equation would be 2, 7, 4, and 6 respectively.
Balancing chemical equationThis requires that the number of atoms of each element is the same both on the reactant and product's sides.
Hence, the balanced equation of the reaction becomes:
[tex]2C_2 H_6 O+ 7O_2 --- > 4CO_2 +6H_2 O[/tex]
Thus, the coefficient for each species would be 2, 7, 4, and 6 respectively.
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Which of the following shows the wavelengths of light that an atom gives off when an electron falls to a lower energy level?
O A. Absorption spectrum
O B. Quantum spectrum
O C. Electromagnetic spectrum
O D. Emission spectrum
The wavelengths of light that an atom gives off when an electron falls to a lower energy level corresponds to Emission spectrum , Option D is the correct answer.
What is Emission Spectrum ?
Light is absorbed or emitted when an electron jumps or falls into an energy level.
The energy of light absorbed or emitted is equal to the difference between the energy of the orbits.
Therefore , the wavelengths of light that an atom gives off when an electron falls to a lower energy level corresponds to Emission spectrum.
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Which of these is a primary characteristic used to describe a clastic sedimentary rock?
A. Types of shells
B. Minerals present
C. Size of the rock
D. Grain size
All light rays parallel to the optical axis of a concave mirror are:
refracted.
reflected through the focal point.
diffused.
incandescent.
Answer:
A. Refracted
Explanation:
Incident rays parallel to the optical axis are reflected from the mirror.
What is the length of the paper clip in cm
Answer:
24.5 cm
Explanation:
It would be really complicated to type out, so I've attached an image of how I solved this:
*I separated the paperclip into different sections, figured out the length of those sections, and added them together.
(sorry that my work isn't the neatest)
answer number ! and fill in the unkown
The identity of the unknown compound is Urea from the Table# given. The reason for this identification will further be discussed below.
What is melting point?Melting point can be defined as the point at which a substance changes from a solid phase or state to a liquid state
When two substances of different melting points are added together, the total melting point obtained is usually depressed.
From the table,
When urea and benzoic acid is added the melting point range becomes = 117-120When urea and Cinnamic acid is added the melting point range becomes= 100-125, and both of which is lower than the individual melting points.Therefore, the identity of the unknown compound is Urea from the Table# given.
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