: The Atom
~Sarah Robinsen
IN A CHEMICAL CHANGE DOES THE ORIGINAL SUBSTANCE DISSAPPEAR ...?
What was used in the first voltaic cell to allow for ion flow between the solutions of CuSO4 and ZnSO4?
A. a porous barrier
B. a non-porous barrier
C. a platinum bridge
D. a salt bridge
In the first voltaic cell, a salt bridge was used for ion flow between CuSO4 and ZnSO4 solutions. The salt bridge ensured electrical neutrality within the circuit and allowed for ion exchange to maintain cell function.
Explanation:In the first voltaic cell, a salt bridge was used to allow for ion flow between the solutions of CuSO4 and ZnSO4.
The purpose of the salt bridge is not only to maintain electrical neutrality within the internal circuit, but is also to permit the exchange of ions (transfer of charge). Without the salt bridge, the solution would rapidly reach the point where they could no longer release or accept ions, causing the voltaic cell to stop working.
The device, therefore, significantly enhanced the effectiveness and longevity of voltaic cells, playing an integral role in the advancement of electrochemistry.
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group 7a of the periodic table contains the most or least reactive elements
What do an electron and a neutron have in common?
Hydrochloric is
an acid
a base
a neutral
Answer:
A. acid
Explanation:
If youve ever heard the term, hydrochlori acid, then you would know it is an acid. Since it has a ph level lower than 7 it is considered an acid, due to the fact that a base woul dbe higher than 7 and neutral would be 7. Hope this helps!
Which of the following are most likely to form a metallic bond?
several gold atoms
copper and chlorine
magnesium and chlorine
several chlorine atoms
Final answer:
Several gold atoms are most likely to form a metallic bond since gold is a metal, capable of creating a lattice with a sea of delocalized electrons typical of metallic bonding.
Explanation:
The question revolves around identifying which scenario most likely forms a metallic bond. Metallic bonds are a type of chemical bond found in metal elements where the atoms contribute their valence electrons to form a 'sea of electrons' that are delocalized over all the atoms. This allows for a structure where positive metal ions are immersed in a sea of mobile electrons. Such bonds are typically found in elemental metals or alloys, not compounds with nonmetals like chlorine.
Among the given options, several gold atoms are most likely to form a metallic bond. This is because gold is a metal, and when multiple gold atoms come together, they form a metallic lattice with a sea of delocalized electrons, which is characteristic of metallic bonding. Copper and chlorine, as well as magnesium and chlorine, will more likely form ionic bonds due to the metal reacting with a nonmetal. Chlorine atoms alone form covalent bonds with each other, creating diatomic molecules, not metallic bonds.
Explain how conduction can increase the temperature of the air above Earth's surface. ...?
The temperature of the air above Earth's surface is mainly increased through convection, where warm air becomes less dense and rises, getting replaced by cooler air in a cycle. Conduction is inefficient over large distances, and radiation also contributes to heat transfer in the environment.
Explanation:Conduction is the process where heat is transferred through direct contact between materials, but conduction alone is not very efficient for warming the air above Earth's surface over large distances or in short times. Instead, the increase in air temperature is largely due to convection. This process involves the movement of warm air upward as it becomes less dense when heated, creating buoyant forces. As the warmer air rises, it is replaced by cooler air from surrounding areas, which then gets heated by the Earth's surface. In this way, convection creates a cycle that effectively distributes heat throughout the atmosphere.
Another form of heat transfer that plays a role in the earth's atmosphere and engine cooling is radiation. Radiation is the emission of energy as electromagnetic waves, which can transfer heat without the need for a medium. This is why we experience warmth from the sun even though there is a vacuum of space between the Earth and the sun.
\
Conduction is less efficient for warming the atmosphere and is surpassed by convection, where warm air rises due to decreased density as it heats, creating a cycle that distributes heat in the atmosphere.
Explanation:Conduction can increase the temperature of the air above Earth's surface through the process where heat is transferred through the direct contact of atoms and molecules. However, it is relatively inefficient for heating the atmosphere significantly because conduction is not effective over large distances and short time frames. Instead, the warming of the air is primarily the result of convection currents: warm air heated at the surface expands, becomes less dense, and rises, being replaced by cooler air that gets heated in turn. This creates a circulation pattern that helps distribute heat. It is due to the natural convection driven by buoyant forces that large-scale atmospheric circulation and ocean currents transfer heat around the globe, NOT primarily through conduction.
Which of the answer choices best describes how electrons move, according to modern atomic theory?
They vibrate in place.
They move like planets.
They move in orbitals.
They slide past each other.
What colors make the color turquoise?
Answer:
Two of them Lol
Explanation:
Which atomic property is different in each isotope of an element?
Which statement is true about oxygen-17 and oxygen-18?
Students in Mr. Klein’s chemistry class are conducting an experiment to calculate the specific heat of a copper sample. Mr. Klein requires each lab team to repeat the experiment until their percent error is 2% or less. Percent error is calculated using observed values (those students calculate from their lab results) and the true value (the accepted value based on reference). The formula for percent error is: (observed – true) x 100 true If the accepted value for the specific heat of copper is 0.385 J/g°C, which of the following lab teams have an unresolved problem on their hands
a.
team 1: calculates 0.392 J/gºC
b.
team 2: calculates 0.395 J/gºC
c.
both teams
d.
neither team
Final answer:
Team 2 has a percent error greater than 2% with their specific heat calculation of copper, while Team 1's percent error is within the acceptable range. Thus, Team 2 has an unresolved problem regarding their experiment.
Explanation:
To determine which lab teams have an unresolved problem based on their calculation of the specific heat of copper, we first need to calculate the percent error using the given formula:
Percent error = ((observed - true) × 100) / true
Where 'observed' is the experimental value and 'true' is the accepted value.
The accepted value for the specific heat of copper is 0.385 J/g°C. We can now calculate the percent error for each team:
Team 1: ((0.392 - 0.385) × 100) / 0.385 = approximately 1.82%Team 2: ((0.395 - 0.385) × 100) / 0.385 = approximately 2.60%Team 1 has a percent error within the 2% limit set by Mr. Klein, while Team 2 has exceeded it. Therefore, the answer is:
b. team 2: calculates 0.395 J/gºC
A teacher makes the following statement.
“Gasoline boils at a relatively low temperature (about 150°C). The kerosene is removed at around 200°C, followed by diesel oil at 300°C and fuel oil at around 370°C.”
What topic is the teacher most likely talking about?
a. distillation of a mixture
b. filtration of a pure substance
c.evaporation of a mixture
d. sorting of a pure substance
Answer:
The correct answer is option a.
Explanation:
According the question, boiling points of different liquids are discussed which means that if we take all these liquids in single mixture we can separate them from each other on the basis of their difference in boiling point. And the technique which employs this principle is distillation process.
Hence, we can say teacher is most likely talking about distillation of a mixture of oils.
Distillation is a process which is used to separate mixture of different liquids from each other. In this process, during the course of boiling of mixture liquid compound with lower boiling points vaporizes first leaving behind the liquid with higher boiling point behind.
And vapors of boiled liquid are condensed down in a separate container for the collection.
Which sentence describes an example of sublimation?
A.Dew forms on leaves on a cold morning.
B.Liquid deodorant sprayed on a person’s body evaporates.
C.Dry ice changes to carbon dioxide when kept in an open container.
D.Ice cream in a bowl melts.
E.Water vapor condenses on a cold surface and forms droplets.
If an object is only partially submerged in a fluid, which of the following is true?
a.
The volume of the displaced fluid equals the volume of the object.
b.
The density of the fluid equals the density of the object.
c.
The density of the fluid is greater than the density of the object.
d.
The density of the fluid is less than the density of the object.
If an object is only partially submerged in a fluid, the correct statement is; The volume of the displaced fluid equals the volume of the object. Option A is correct.
This statement is known as Archimedes' principle. According to this principle, when an object is immersed or partially submerged in a fluid, it experiences an upward buoyant force equal to the weight of the fluid it displaces. The volume of the displaced fluid will be equal to the volume of submerged portion of the object.
"The density of the fluid equals the density of the object" is not necessarily true. The density of the fluid and the object can be different, and it does not directly determine the behavior of a partially submerged object.
The density of the fluid is greater than the density of the object" and "The density of the fluid is less than the density of the object" are not universally true statements. The density comparison between the fluid and the object does not determine the behavior of a partially submerged object. It depends on the relative densities and the shape of the object.
Hence, A. is the correct option.
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A change in temperature causes a change in mass.
True
False
Answer:
false i hope this works
Explanation:
You carefully weigh out 14.00 g of CaCO3 powder and add it to 56.70 g of HCl solution. You notice bubbles as a reaction takes place. You then weigh the resulting solution and find that it has a mass of 64.96 g . The relevant equation is
CaCO3(s)+2HCl(aq)→H2O(l)+CO2(g)+CaCl2(aq)
Assuming no other reactions take place, what mass of CO2 was produced in this reaction?
Answer : The mass of [tex]CO_2[/tex] produced will be, 6.16 grams.
Explanation : Given,
Mass of [tex]CaCO_3[/tex] = 14 g
Mass of [tex]HCl[/tex] = 56.70 g
Molar mass of [tex]CaCO_3[/tex] = 100 g/mole
Molar mass of [tex]HCl[/tex] = 36.5 g/mole
Molar mass of [tex]CO_2[/tex] = 44 g/mole
First we have to calculate the moles of [tex]CaCO_3[/tex] and [tex]HCl[/tex].
[tex]\text{Moles of }CaCO_3=\frac{\text{Mass of }CaCO_3}{\text{Molar mass of }CaCO_3}=\frac{14g}{100g/mole}=0.14moles[/tex]
[tex]\text{Moles of }HCl=\frac{\text{Mass of }HCl}{\text{Molar mass of }HCl}=\frac{56.70g}{36.5g/mole}=1.55moles[/tex]
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,
[tex]CaCO_3(s)+2HCl(aq)\rightarrow CO_2(g)+H_2O(l)+CaCl_2(aq)[/tex]
From the balanced reaction we conclude that
As, 1 moles of [tex]CaCO_3[/tex] react with 2 mole of [tex]HCl[/tex]
So, 0.14 moles of [tex]CaCO_3[/tex] react with [tex]0.14\times 2=0.28[/tex] moles of [tex]HCl[/tex]
From this we conclude that, [tex]HCl[/tex] is an excess reagent because the given moles are greater than the required moles and [tex]CaCO_3[/tex] is a limiting reagent and it limits the formation of product.
Now we have to calculate the moles of [tex]CO_2[/tex].
As, 1 moles of [tex]CaCO_3[/tex] react to give 1 moles of [tex]CO_2[/tex]
So, 0.14 moles of [tex]CaCO_3[/tex] react to give 0.14 moles of [tex]CO_2[/tex]
Now we have to calculate the mass of [tex]CO_2[/tex].
[tex]\text{Mass of }CO_2=\text{Moles of }CO_2\times \text{Molar mass of }CO_2[/tex]
[tex]\text{Mass of }CO_2=(0.14mole)\times (44g/mole)=6.16g[/tex]
Therefore, the mass of [tex]CO_2[/tex] produced will be, 6.16 grams.
The mass of CO2 produced in the reaction is 5.74 g.
Explanation:To calculate the mass of CO2 produced in the reaction, we need to determine the change in mass caused by the formation of CO2. We start with the mass of CaCO3 (14.00 g) and the mass of HCl solution (56.70 g). The total mass of the reactants is the sum of these two: 14.00 g + 56.70 g = 70.70 g.
The mass of the resulting solution is 64.96 g, so the change in mass is 70.70 g - 64.96 g = 5.74 g. This change in mass corresponds to the mass of CO2 produced in the reaction, so the mass of CO2 is 5.74 g.
Balance: (NH4)2CO3-->NH3+H2O+CO2 ...?
Consider the equation: A+3B--->4C. If 3.0 moles of A is reacted with 6.0 moles of B, which of the following is true after the reaction is complete? Explain your answer.
a.) A is the leftover reactant b/c you only need 2 moles of A and have 3.
b) A is the leftover reactant b/c for every 1 mole of A, 4 moles of C are produced.
c) B is the leftover reactant b/c you have more moles of b than A.
d) B is the leftover reactant b/c 3 moles of B react with every 1 mole of A.
e) Neither reactant is leftover.
Final answer:
When analyzing the reaction A + 3B \(\rightarrow\) 4C with 3.0 moles of A and 6.0 moles of B, B becomes the limiting reactant because it is not present in sufficient quantity to fully react with A, leaving some A unreacted.
Explanation:
Given the equation A + 3B \(\rightarrow\) 4C, we are dealing with a stoichiometry problem where 3.0 moles of A is reacted with 6.0 moles of B. To determine which reactant is leftover, we analyze the stoichiometric relationships. According to the equation, for every mole of A, we need 3 moles of B to completely react. For 3.0 moles of A, 9.0 moles of B would be required. Since only 6.0 moles of B are available, B becomes the limiting reactant. Consequently, some amount of A will not react and will be left over.
Therefore, choice a is incorrect because it misinterprets the stoichiometry required for A. Choice b is incorrect as it confuses the product formation with the reactant consumption. Choice c and choice e are incorrect because B, not having more moles than required, cannot be leftover or support a scenario where neither reactant is leftover. Choice d is the correct choice, as it accurately reflects the stoichiometric relationship that 3 moles of B react with every 1 mole of A, making B the limiting reactant due to its insufficient quantity to react with all of A provided.
If the net force on a 75-N object is 375 N from the left, in what direction will the object move?
Question 2 options:
toward the right
toward the left
in a straight line
to the side
Answer:
It will move to the right.
Explanation:
I took the test and wasn't very sure about this answer but I got it right. I also attached a photo down below for proof.
Good luck on your quiz! Have a great day. :)
Final answer:
With a net force of 375 N to the left, the 75-N object will move toward the left, in a straight line, according to Newton's second law of motion.
Explanation:
If the net force on a 75-N object is 375 N from the left, the object will move in the direction of the net force, which is to the left. This is in accordance with Newton's second law of motion, which states that an object will accelerate in the direction of the net external force.
The net force is a vector quantity, meaning it has both a magnitude and a direction. In this case, a net force to the left means that the force vector is pointing to the left, and therefore, the object will move toward the left.
It's important to clarify that the object will move in a straight line towards the left unless acted upon by another force that could change its direction. However, based on the information given, we can conclude that the object will just move toward the left.
Chlorophyll a is one of the green pigments found in plants. Chlorophyll a has the molecular formula C55H72MgN4O5. How many atoms are in this molecule?
A)136
B)137
C)138
molecular formula is the acutal composition of the components making up the compound
chlorophyll a molecular formula is - C₅₅H₇₂MgN₄O₅
so we have to find how many atoms are in 1 molecule
for this we have to add all the atoms of each element making up this 1 molecule
number of atoms of each element
C - 55
H - 72
Mg - 1
N - 4
O - 5
the sum of all the atoms - 55 + 72 + 1 + 4 + 6 = 138
answer is C ) 138
When reacting 45g of magnesium with oxygen, 50.0g of magnesium oxide is produced. Calculate the theoretical yield and percent yield.
Humans exhale carbon dioxide when they breathe. if the concentration of carbon dioxide in the air that people breathe gets too high, it can be fatal. therefore, in space shuttles, submarines, and other sealed environments, it is common to use "air scrubbers" to remove carbon dioxide from the air. the air scrubbers on the space shuttle remove carbon dioxide by using lithium hydroxide (lioh). the reaction in the air scrubbers is shown below: co2 2lioh li2co3 h2o each astronaut produces 8.8 × 102 g co2 per day that must be removed from the air on the shuttle. if a typical shuttle mission is 9 days, and the shuttle can carry 3.50 × 104 g lioh, what is the maximum number of people the shuttle can safely carry for one mission?
Answer: 4 people can carry safely for one mission.
Explanation: To calculate the number of moles of [tex]CO_2[/tex] produces by 1 astronaut, we use the formula:
[tex]Moles=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ....(1)
Molar mass of carbon dioxide = 44 g/mol
Given mass of carbon dioxide = [tex]8.8\times 10^2g[/tex]
Putting values in equation 1, we get:
[tex]Moles=\frac{8.8\times 10^2g}{44g/mol}=200moles[/tex]
We are given a chemical equation:
[tex]CO_2+2LiOH\rightarrow Li_2CO_3+H_2O[/tex]
Moles of LiOH by using equation 1, we get:
Molar mass of LiOH = 24 g/mol
[tex]Moles=\frac{3.40\times 10^4g}{24g/mol}=1458.3moles[/tex]
By stoichiometry of the reaction,
2 moles of LiOH produces 1 mole of [tex]CO_2[/tex]
So. 1458.3 moles of LiOH will produce = [tex]\frac{1}{2}\times 1458.3=729.15moles[/tex] of [tex]CO_2[/tex]
Applying Unitary method:
As, 200 moles of [tex]CO_2[/tex] are produced by 1 astronaut
So, 729.15 moles of [tex]CO_2[/tex] will be produced by = [tex]\frac{1}{200}\times 729.15=3.64\approx 4[/tex] astronauts.
Which statement best describes the effect of low ionization energies and low electronegativities on metallic bonding?
The valence electrons are easily delocalized.
The valence electrons stay in a single orbital.
The valence electrons break free of the crystals.
The valence electrons move closer to the nuclei.
Answer:
the valence electrons are easily delocalized.
Explanation:
a gas has a volume of 95 mL at a pressure of 930 torr. What volume will the gas occupy if the pressure is increased to 970 torr and the temperature remains constant
Answer:
The volume occupied by the gas at pressure 970 torr is 91.08 mL.
Explanation:
To calculate the new pressure, we use the equation given by Boyle's law.
This law states that pressure is directly proportional to the volume of the gas at constant temperature.
The equation given by this law is:
[tex]P_1V_1=P_2V_2[/tex] (at constant temperature)
where,
[tex]P_1\text{ and }V_1[/tex] are initial pressure and volume.
[tex]P_2\text{ and }V_2[/tex] are final pressure and volume.
We are given:
[tex]P_1=930 Torr\\V_1=95 mL\\P_2=970 Torr\\V_2=?[/tex]
Putting values in above equation, we get:
[tex]930 Torr\times 95 mL=270 Torr \times V_2\\\\V_2=\frac{P_1V_1}{P_2}=\frac{930 Torr\times 95 mL}{270 Torr}=91.08 mL[/tex]
The volume occupied by the gas at pressure 970 torr is 91.08 mL.
A 14.01 g sample of N2 reacts with 3.02 g of H2 to form ammonia (NH3). If ammonia is the only product, what mass of ammonia is formed?
How many moles of oxygen atoms are contained in the following?
1.67 x 10-2mol CuSO4-5 H₂O
The moles of oxygen atoms in 1.67 x 10⁻² mol CuSO₄·5H₂O is found to be approximately 0.1503 moles.
First, we need to determine the total number of oxygen atoms in one formula unit of CuSO₄·5H₂O. The formula CuSO₄·5H₂O contains:
4 oxygen atoms from CuSO₄5 oxygen atoms from 5 molecules of H₂OTherefore, each formula unit of CuSO₄·5H₂O contains a total of 4 + 5 = 9 oxygen atoms.
Next, we calculate the number of moles of oxygen atoms in 1.67 x 10⁻² mol of CuSO₄·5H₂O:
Moles of CuSO₄·5H₂O = 1.67 x 10⁻² molTotal oxygen atoms per mol = 9Moles of oxygen atoms = (1.67 x 10⁻² mol) x 9 = 0.1503 molThus, the number of moles of oxygen atoms in 1.67 x 10⁻² mol CuSO₄·5H₂O is 0.1503 moles.
Which of the following elements is classified as a halogen?
a. b
b. ba
c. be
d. br
The structure of a solid is due to its
Which change takes place in a nuclear fusion reaction?
A) Matter is converted to energy.
B) Energy is converted to matter.
C) Ionic bonds are converted to covalent bonds.
D) Covalent bonds are converted to ionic bonds.
Answer:
Matter is converted to energy.
Explanation:
In a chemical reaction we consider that matter is conserved.It means in a chemical reaction the amount of matter on the reactant side is equal to the amount of matter on the product side.
However in case of nuclear reaction the matter gets converted to energy and thus there is loss of matter. Due to this conversion of matter into energy high amount of energy is associated with the nuclear reactions.
There is no change of ionic bond to covalent or vice versa.