How many copper atoms are in a pure copper statue with a mass of 198 kg?
Answer:
No.of copper atoms= no.of moles x No x atomicity
(No - avagardro's number )
= wt / atomic mass x No x 1
= 198 x 10 ^3 g / 63.5 x No
= 3.118 x 10^3 x 6.02 x 10^23
= 18.77 x 10^26 atoms.
How does stoichiometry support the law of conservation of mass?
A It compares the mass of the reactants to the number of moles of reactants.
B It compares the mass of each reactant to the mass of each product.
C It compares the mass of the products to the number of atoms in the products.
D It compares the mass of the products to the mass of the reactants. ***
The stoichiometry supports the law of conservation of mass by comparing the mass of the products to the mass of the reactants.
What is stoichiometry?Stoichiometry is the measurement of the reactant and product of a reaction.
It is found in the law of conservation of mass, which says that the mass of the reactant is equal to the mass of the product.
Due to stoichiometry, if the mass of the product is known then, the mass of the reactant can be known.
Thus, the correct option is D.
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Which of these statements accurately describes polymers?
Polymers are macromolecules.
Polymers are simple molecules.
Polymers are made of metal atoms.
Polymers contain double bonds.
Answer:
Its A.) Polymers are macromolecules
Explanation:
Answer:
The correct answer that you are looking for is A.) Polymers are macromolecules.
18 points ! Kinetic Molecular Theory has to do with
A. the identity of gas particles.
B. the pressure of gas particles.
C. the motion of gas particles.
D. the volume of gas particles.
Answer:
C. the motion of gas particles.
Explanation:
The kinetic molecular theory is a simple but very effective model that effectively explains ideal gas behavior. The theory assumes that gases consist of widely separated molecules of negligible volume that are in constant motion, colliding elastically with one another and the walls of their container with average velocities determined by their absolute temperatures.
At 1 atm, how much energy is required to heat 59.0 g H2O(s) at −22.0 ∘C to H2O(g) at 141.0 ∘C? STRATEGY: Calculate the energy needed for each temperature change or phase change individually. a. The energy needed to heat 59.0 g H2O(s) from −22.0 ∘C to its melting point. b. The energy needed to melt 59.0 g H2O(s) at its melting point. c. The energy needed to heat 59.0 g H2O(l) from the melting point to the boiling point. d. The energy needed to boil 59.0 g H2O(l) at its boiling point. e. The energy needed to heat 59.0 g H2O(g) from the boiling point to 141.0 ∘C. Sum the energies from each step and convert to kilojoules. Step 1. a. Going from −22.0 ∘C to the melting point of H2O (0 ∘C) is a temperature change of 22.0 ∘C. How much energy is needed to heat 59.0 g H2O(s) by 22.0 ∘C if its specific heat is 2.087 J/(g× ∘C)?
Answer:
The answer is "2736.1 J"
Explanation:
[tex]m= 59.0 \ g\\\\t_2 = -22\\\\\Delta t= t_1-t_2\\\\[/tex]
[tex]= 0-(-22)\\= 22[/tex]
specific heat for ice = 2.108 [tex]\frac{J}{gk} \\[/tex]
Formula:
[tex]\bold{Q= mc \Delta t} \\[/tex]
[tex]= 59 \times 2.108 \times 22\\\\= 2736.1 \ \ J[/tex]
A student conducts an investigation to determine which magnet is strongest: the horseshoe, the bar, or the ring. The student tests each magnet one time using the same metal object and announces that the bar magnet is strongest. What is wrong with the student's reasoning?
Answer:
Each magnet should have been tested on many different magnetizable materials
Explanation:
In designing an experiment such as that outlined above, the experimental design should have included many different magnetizable materials.
All the types of magnets; the horseshoe, the bar, and the ring magnet should have been tested using many different magnetizable materials apart from the metal object. By so doing, the strongest magnet can be effectively determined without bias because it will attract the greatest number of magnetizable materials.
Again, the shape of the magnet affects its ability to attract objects. Hence, different shapes of magnets can not effectively be compared for relative magnetic strength.
Explanation:
bold is strong
Describe the changes in membrane permeability that occur at the point of stimulation on the axon.
Answer:
The permeability of a membrane is affected by temperature, the types of solutes present and the level of cell hydration. Increasing temperature makes the membrane more unstable and very fluid.
Explanation:
A volume of 75 mL of 0. 060 M NaF is mixed with 25 mL of 0. 15 M Sr(NO3)2. Calculate the concentrations in the final solution of NO3 - , Na , Sr2 , and F-. (Ksp for SrF2
For a volume of 75 mL of 0. 060 M NaF is mixed with 25 mL of 0. 15 M Sr(NO3)2, the concentrations in the final solution is mathematically given as
[NO3-] = 0.075 M[Na+] = 0.045 M[Sr2+] = 0.015 M[F-] = 0.00012 MWhat are the concentrations in the final solution of NO3 - , Na , Sr2 , and F-.?Generally, the equation for the molarity of NaF is mathematically given as
M NaF= millimoles / total volume
M NaF= = 75 x 0.060 / (75+ 25)
M NaF = 0.045
Where, Sr(NO3)2 molarity = 25 x 0.15 / (75+ 25)
Sr(NO3)2 molarity = 0.0375 M
The Chemmical reaction of Sr and F is
Sr+2 + 2 F ---> SrF2
Therefore,Ksp = [Sr+2] [F-]^2
2.0 x 10^-10 = 0.015 [F-]^2
[F-] = 1.2 x 10^-4 M
In conclusion, the concentrations are
[NO3-] = 0.075 M[Na+] = 0.045 M[Sr2+] = 0.015 M[F-] = 0.00012 MRead more about Concentration
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When any reversible reaction is at equilibrium, what conditions are necessarily true?.
Answer:
Reversible reactions that happen in a closed system eventually reach equilibrium. At equilibrium, the concentrations of reactants and products do not change. But the forward and reverse reactions have not stopped - they are still going on, and at the same rate as each other.
When any reversible reaction is at equilibrium, the conditions are necessarily true are the amount of reactant and products stops changing, and the rate of forward reaction equals rate of backward reaction. The correct options are B and D.
What is a reversible reaction?A reversible reaction occurs when the conversion of reactants to products and the conversion of products to reactants occur at the same time.
A and B can react to form C and D, or C and D can react to form A and B in the reverse reaction. In thermodynamics, this is not the same as a reversible process.
In a closed system, reversible reactions eventually reach equilibrium. The concentrations of both reactants and products remain constant at equilibrium.
But the forward and reverse reactions have not stopped; they are still occurring at the same rate.
Reversible reactions continue until equilibrium is reached, which means that the amounts of reactant and product are balanced.
Thus, the correct options are B and D.
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Your question seems incomplete, the missing options are attached below as image:
reaction of ethene with H2
Answer:
The hydrogenation of ethene
Ethene reacts with hydrogen in the presence of a finely divided nickel catalyst at a temperature of about 150°C. Ethane is produced. This is a fairly pointless reaction because ethene is a far more useful compound than ethane!
Explanation:
1. Why is sodium kept immersed in keroscne oil?
Explanation:
Sodium and Potassium are highly reactive metals and react vigorously with the oxygen, carbon dioxide and moisture present in the air such that it may even cause a fire. To prevent this explosive reaction, Sodium iskept immersed in kerosene becauseSodium doesn't react with kerosene
Which term is defined as the sum of protons and neutrons in an atom.
Answer:
Mass number
Explanation:
2. Does the aluminum sample (the can) contain more than, (less than or exactly one mole of aluminum? Support answer with calculation.
Answer:
than, (less than or exactly one mole
Which of the following properties of pure solvents increase when a solute is added?
a. Freezing point
b. Vapor pressure
c. Boiling point
d. Cohesion
A student dissolves 73 g of sodium nitrate, NaNO3, in 100 mL of water and observes a clear, colorless
solution. The student begins to add more sodium nitrate to the solution and it instantly becomes a cloudy,
heterogeneous mixture. The original solution the student prepared is best described as
unsaturated
saturated
immiscible.
supersaturated
10. The property of water that accounts for its' ability bead up into round drops is
a. Adhesion
b. Capillary action
b. Cohesion
d. Dispersion forces
Answer:
c. Cohesion
Explanation:
Hope this helps and have a nice day
6. 0.465 mole sample of gas exerts 4.43 atm of pressure in a 2.25 L container. What is the temperature of the gas in the container?
Answer:
T = 262KExplanation:
n = 0.465
P = 4.43 atm
V = 2.25 L
T = ?
Follow this equation below
PV = nRT4.43 x 2.25 = 0.465 x 0.08206 x T
9.97 = 0.038 x T
(Dividing both sides by 0.038 to get rid of it)
T = 262K or you could say 262.4K
Hope this helps!!
Question
Write the correct skeleton equation for the following:
fluorine gas reacts with calcium metal to form
solid calcium fluoride
Let's see
Fluorine reacts with Calcium metal to form calcium fluoride
[tex]\\ \rm\rightarrowtail Flourine+Calcium\longrightarrow CaF_2[/tex]
Write states[tex]\\ \rm\rightarrowtail Fluorine(g)+Calcium (s)\longrightarrow Calcium\: Fluoride (s)[/tex]
The chemical equation when fluorine gas reacts with calcium metal to form solid calcium fluoride is Ca + F₂[tex]\rightarrow[/tex] CaF₂.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Write 483,928 in each form.
Word:
Expanded:
A mercury lamp emits radiation with a wavelength of 4. 36x 105 cm. A. What is this wavelength in meters?
how many grams of baf2 are in 3.7 moles of baf2
To convert moles to gram multiply 3.7 moles of BaF2 to the molar mass of BaF2
BaF2 molar mass = 175.326
3.7 moles x 175.326g = 648.70g BaF2
whats the biggest thing in the whole universe
Answer:
The biggest thing in the universe is a supercluster known in the universe is the Hercules-Corona Borealis Great Wall.
Explanation:
What is the specific heat of titanium if the temperature of a 36.7 g sample of titanium is increases by
4.8 °C when 91.6 J of heat is added?
Answer:
what is the initial temperature? i can answer once I know. if it doesnt say, then I dont know and I'll delete this
Which statement best describes one rule for determining the relative age of a rock layers
Jackson enjoys looking up at the night sky and writing about the variety of objects he sees. On one special occasion, he wrote in his journal that he saw a streak of light going across part of the sky. Which answer best describes what Jackson saw? * 1 point Meteorite: A cold mixture of dust and ice that develops a long tail as it nears the sun Meteor: A cold mixture of dust and ice that develops a long tail as it nears the sun Meteorite: A streak of light made when an object burns up as it enters Earths's atmosphere Meteor: A streak of light made when an object burns up as it enters Earth's atmosphere
9514 1404 393
Answer:
Meteor: A streak of light made when an object burns up as it enters Earth's atmosphere
Explanation:
A meteorite is an object that has come from space and hit Earth.
A comet is a space object that develops a tail as it nears the sun. It is believed to be a mixture of dust and ice. In general, a comet will appear stationary in the night sky, since it moves rather slowly relative the starry background.
A meteor is a space object that makes a streak of light across the sky as it burns up in the atmosphere. (It may or may not become a meteorite, depending on the degree to which it burns up.)
__
UFOs have also been known to make streaks of light when moving across the sky.
Answer:
A streak of light made when an object burns up as it enters Earth's atmosphere
Explanation:
100 % 2021
A chemist wants to extract copper metal from copper chloride solution. The chemist places 1.50 grams of aluminum foil in a solution of 14 grams of copper (II) chloride. A single replacement reaction takes place. What best explains the state of the reaction mixture after the reaction?
Unbalanced equation: CuCl2 + Al → AlCl3 + Cu (4 points)
Group of answer choices
Less than 6.0 grams of copper is formed, and some aluminum is left in the reaction mixture.
More than 6.5 grams of copper is formed, and some aluminum is left in the reaction mixture.
Less than 6.0 grams of copper is formed, and some copper chloride is left in the reaction mixture.
More than 6.5 grams of copper is formed, and some copper chloride is left in the reaction mixture.
Less than 6.0 grams of copper is formed, and some aluminum is left in the reaction mixture
Stoichiometric calculationsFrom the equation of the reaction:
3CuCl2 + 2Al → 2AlCl3 + 3Cu
Mole ratio of CuCl2 and Al = 3:2
Mole of 1.5 g aluminum foil = 1.5/26.98
= 0.06 moles
Mole of 14 g CuCl2 = 14/134.45
= 0.10 moles
For every 3 moles of CuCl2, 2 mole of Al is needed.
Thus, for 0.10 moles of CuCl2, the mole of Al needed would be:
0.10 x 2/3 = 0.07 moles
CuCl2 is, thus, slightly in excess while Al is the limiting reagent.
Mole ratio of Al and Cu = 2:3
For 0.06 mole Al, the mole of Cu will be: 0.06x3/2 = 0.09 moles
Mass of 0.09 moles Cu = 0.09 x 63.55
= 5.71 g
Thus, less than 6.0 grams Cu is formed while a little CuCl2 would be left in the reaction mixture.
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write the steps for a covalent bond for s2
Answer:
Sulfur, which only needs two electrons to complete it octet, will pick up the two electrons coming from magnesium, becoming the sulfide anion, S2− , in the process. The electrostatic force of attraction will then bring the magnesium cations and the sulfur anions together → an ionic bond i
Arrange the missing steps in the correct order.
Answer:
There's nothing to arrange l
Can someone please help me? :(
Answer:
B and D
Explanation:
They collect equal amounts.of solar energy
Answer:
The answer is
C. B and D
Explanation:
The equator is where there is the most solar energy
B and D are symmetrical over the equator.
Read this excerpt from the play An Adventure for Detective Dennis:
Stars twinkle in the windows of the library.
What element of a play is shown in this text?
Cast of characters
Dialogue
Scene
Setting description
Answer:
the answer is Scene
Explanation:
because it is describing the atmosphere of where the book/play is taking place
Answer:
the answer is Scene
Explanation: