Answer:
40.92%
Explanation:
CaCo₃(s)-->CaO(s)+CO₂(g)
mass of Co2(g)= 1.33grams
mass of CaO(s)=(3.25-1.33)=1.92grams
mass % of CaCO₃ = [tex](\frac{1.33}{3.25} )[/tex]×100%
40.92%
When light bends or changes direction, what is happening? A interaction B movement C reflection D refraction
Answer:
D) Refraction
Explanation:
Refraction is when something is bended or when it changes directions, such as light
The light bends or changes direction when it's being refracted. So the correct option is D.
What is refraction?
The bending of a light ray when it's passing from one medium to another medium is called refraction. The bending of the ray is due to the differences in density between the two media.
The change in the direction of a wave when it's passing from one medium to another is defined as refraction. This is one of the most commonly observed phenomena in nature. The working of optical instruments like magnifying glasses, lenses, and prisms is possible due to refraction.
Also, because of the refraction of light, a person can focus light on their retina and is thus able to see. Whenever a light ray travels at an angle into a medium of different refractive indices, it always refracts. This is a change in speed which results in a change in direction.
There are two laws of refraction. They state that:
"The incident ray refracted ray, and the normal to the interface of two media at the point of incidence all lie on the same plane." "The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant. This is also known as Snell’s law of refraction."[tex]\frac{sin (i)}{ sin (r)} = constant[/tex]
Therefore the correct option is D.
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(7.12F) Which of the following statement(s) is part of the cell theory?*
O A A cell is the smallest unit of life in living organisms
O B All living things are made of cells
O C All cells come from pre-existing cells
O D All of the above
A heated fruit pie often seems to have feeling that it’s warmer than the crust why is this?
What is the predicted oxidation number for a Sulfur ion?
-3
-2
-1
+1
+2
+3
I believe it is -2, though I might be wrong.
does foil keep in the heat well ?
Answer:
Explanation:
yes
Answer:
yes
Explanation:
it acts as a barrier to oxygen and can transfer heat
In general, which group in the periodic table contains elements with the lowest electronegativities?
A. Group 1
B. Group 2
C. Group 16
D. Group 17
When 11.0g of Mg(s) reacts with excess water to produce 5.75g of Mg(OH)2, what is the percent yield of the reaction
The chemical equation is given by :
[tex]Mg +2H_2O-> Mg(OH)_2+H_2[/tex]
From above equation :
24 gm Mg forms -----> 58 gm of [tex]Mg(OH)_2[/tex]
So, 11 g of Mg will form = [tex]\dfrac{11}{24}\times 58=26.58\ gm[/tex].
Now, percentage yield is given by :
[tex]\%\ yield = \dfrac{5.75}{26.58}\times 100\\\\\% \ yield = 21.63\%[/tex]
Therefore, the percentage yield is given by 21.63%.
Hence, this is the required solution.
4. Students sometimes find it necessary to conduct a 2nd, a 3rd and even a 4th weighing of the crucible at the end of the experiment. Which of these masses should be utilized to calculate the percentage of NaHCO3
Answer:
4th
Explanation:
The result of the last weighing of the crucible should be utilized when students want to calculate the percentage of NaHCO3.
This is the best option to take because it is important that the mass of the NaHCO3 remain consistent throughout the calculations so that there will be a very high degree of accuracy in the result obtained.
In the reaction 2H, + O2 + 2H,0, if you have 3 moles of Hydrogen and 1 mole of oxygen, which is the limiting reactant?
Hydrogen
O Oxygen
Answer:
O₂
Explanation:
A quick way to determine Limiting Reactant => divide moles of each substance given in problem by respective coefficient of balanced equation ... the smaller resulting value is the Limiting Reactant.
2H₂ + O₂ => 2H₂O
Given: 3 moles H₂ 1mole O₂
=> 3/2 = 1.5 1/1 = 1
=> O₂ is Limiting Reactant
A reaction at equilibrium has a standard state Gibbs energy of formation of -1.90 kJ per mole at 298K. Calculate the equilibrium constant.
Answer:
Kc = 2.15
Explanation:
Step 1: Given data
Standard state Gibbs energy of formation (ΔG°): -1.90 kJ/molAbsolute temperature (T): 298 KIdeal gas constant (R): 8.314 J/K.molEquilibrium constant (Kc): ?Step 2: Calculate the equilibrium constant
We will use the following expression.
ΔG° = -R × T × lnKc
-1.90 × 10³ J/mol = -8.314 J/K.mol × 298 K × lnKc
Kc = 2.15
Describe the difference between an atom and an ion. Include specific details and
include an example to earn full credit.
what is the density of an liquid if its mass is 2,909 g and its volume is 0.57 gallons
Answer:
Density of liquid = 5103.5 g/mL
Explanation:
Given data:
Density of liquid = ?
Mass of liquid = 2909 g
Volume of liquid = 0.57 gal
Solution:
First of all we will convert the volume into mL.
Volume of liquid = 0.57 gal × 3785 mL/1 gal
Volume of liquid = 2157.68 mL
Now we will calculate the density.
d = 2909 g/0.57 gal
d = 5103.5 g/mL
19. Which two have the same mass? a. Atoms 1 and 2 b. Atoms 2 and 4 c. Atoms 1 and 4 d. Atoms 2 and 3
Answer:
Atom 2 and 4
Explanation:
The following data were obtained from the question:
Atom > Proton > Neutron > Electron
1 >>>>> 8 >>>>>> 10 >>>>>> 8
2 >>>> 10 >>>>>> 9 >>>>>> 10
3 >>>>> 9 >>>>>> 9 >>>>>> 9
4 >>>>> 8 >>>>>> 11 >>>>>> 8
Next, we shall determine the mass number of each atom. This can be obtained as illustrated below:
Atom 1:
Proton = 8
Neutron = 10
Mass number =?
Mass number = Proton + Neutron
Mass number = 8 + 10
Mass number = 18
Atom 2:
Proton = 10
Neutron = 9
Mass number =?
Mass number = Proton + Neutron
Mass number = 10 + 9
Mass number = 19
Atom 3:
Proton = 9
Neutron = 9
Mass number =?
Mass number = Proton + Neutron
Mass number = 9 + 9
Mass number = 18
Atom 4:
Proton = 8
Neutron = 11
Mass number =?
Mass number = Proton + Neutron
Mass number = 8 + 11
Mass number = 19
Summary:
Atom >>>> Mass number
1 >>>>>>>> 18
2 >>>>>>>> 19
3 >>>>>>>> 18
4 >>>>>>>> 19
From the above illustration,
Atom 1 and 3 have the same mass number
Atom 2 and 4 also have the same mass number
20. Select the false statement below.A) Generally speaking, as you go across a period in the periodic table, the effective nuclear charge (Zeff) increases because each successive element contains more protons in the nucleus than the previous element and the outer electrons are all in the same shell as you go across a period.B) Generally speaking, the heavier halogens can be predicted to exhibit greater shielding of the outer-shell electrons by the inner-shell electrons than lighter halogens.C) Generally speaking, non-metallic elements have less effective nuclear charge (Zeff) than metallic elements in the same period.D) Generally speaking, as you go down a group in the periodic table, there is successively greater shielding of the outer-shell electrons by the inner-shell electrons.
Answer:
C) Generally speaking, non-metallic elements have less effective nuclear charge (Zeff) than metallic elements in the same period
Explanation:
Let us remember that metals are found towards the left hand side of the periodic table while nonmetals are found towards the right hand side of the periodic table.
The magnitude of effective nuclear charge increases from left to right in the periodic table as the size of the nuclear charge increases without a corresponding increase in the number of shells. This implies that as one moves from metals to nonmetals, there is a significant increase in the magnitude of effective nuclear charge which simultaneously leads to an increase in ionization energy across the period.
Therefore, it is a false statement that; 'Generally speaking, non-metallic elements have less effective nuclear charge (Zeff) than metallic elements in the same period'.
The statement that can be regarded as false is : C) Generally speaking, non-metallic elements have less effective nuclear charge (Zeff) than metallic.
Periodic table can be regarded as table of chemical element which been arranged in You'll in rows and columns.The horizontal rows can be regarded as periods and it moves from from left to right, while the vertical columns are regarded as group which move from from up to down.Generally speaking, there is greater shielding of the outer-shell electrons as one move down the group.The halogen usually have a shielding of the outer-shell electrons compare to lighter halogenTherefore, Periodic table has its arrangements in periods and group.
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The table below lists the isotope mass and isotope percent abundance of the element that is used in the production of stainless steel.
Isotope Mass % Abundance
53.938882 2.365
52.940651 9.500
51.940509 83.790
49.946046 4.345
Based on the information in this table, which element is used in the production of stainless steel?
A.
Fe
B.
Cr
C.
C
D.
Ni
Answer:
the answer is cr
Explanation:
just did this test in chemistry the answe cr as in chromium, xoxo live stream positions by ariana btw
Identify each substance as a strong electrolyte, weak electrolyte, or non-electrolyte. H 2 C O 3 Choose... MgCl 2 Choose... NaCl Choose... O 2 Choose... C Choose... (NH 4 ) 3 PO 4 Choose...
Explanation:
Strong electrolyte is a solution/solute that almost completely ionizes or dissociates in a solution.
Weak electrolyte does not completely dissociate in an aqueous solution.
Non electrolyte are poor conductors and do not dissociate into ions.
H 2 C O 3 --> Weak Electrolyte
MgCl 2 --> Strong Electrolyte
NaCl --> Strong Eletrolyte
C --> Non Electrolyte
(NH 4 ) 3 PO 4 --> Strong Electrolyte
Identifying each substance :
H 2 C O 3 - Weak ElectrolyteMgCl 2 - Strong ElectrolyteNaCl - Strong ElectrolyteC - Non Electrolyte(NH 4 ) 3 PO 4 - Strong ElectrolyteElectrolyteAn electrolyte may be a medium containing particles that's electrically conducting through the development of particles, but not conducting electrons.
Strong electrolyte could be a solution/solute that nearly totally ionizes or dissociates in a solution.
Weak electrolyte does not totally separate in an aqueous solution.
Non electrolyte are destitute conductors and don't separate into ions.
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How many moles of copper are in a 0.53 gram sample?
Answer:
8.3 × 10⁻³ mol Cu
Explanation:
Step 1: Define
Molar Mass of Cu - 63.55 g/mol
Given 0.53 g Cu
Step 2: Use Dimensional Analysis
[tex]0.53 \hspace{3} g \hspace{3} Cu(\frac{1 \hspace{3} mol \hspace{3} Cu}{63.55 \hspace{3} g \hspace{3} Cu} )[/tex] = 0.00834 mol Cu
Step 3: Convert
0.00834 mol Cu = 8.34 × 10⁻³ mol Cu
Step 4: Simplify
We are given 2 sig figs.
8.34 × 10⁻³ mol Cu ≈ 8.3 × 10⁻³ mol Cu
To convert from one resonance structure to another, ________. To convert from one resonance structure to another, ________. only electrons can be moved electrons must be added only atoms can be moved electrons and atoms can both be moved neither electrons nor atoms can be moved
Answer:
To convert from one resonance structure to another, only electrons can be moved
Explanation:
The resonance structure is known as the molecular bonding system in which a hybrid, called resonance, is formed from two or more Lewis structures that have different electronic distributions. The degree of similarity and the number of resonant structures measure the stability of the compound in which it occurs.
In organic compounds, there are cases in which, from the formula recorded as a function of the Lewis structures, it is impossible to determine with precision the exact structure of a molecule. Thus, in a nitrile chloride molecule, there exist two alternative structures distinguished only based on the positions of its electrons, but not on those of its atoms.
What factor (s) affect kinetic energy?
Answer: The kinetic energy of an object depends on both its mass and its speed. Kinetic energy increased as mass and speed are increased
Explanation: Google lol
How does the law of conversation of mass apply to this reaction: C2H4+O2>H2O+CO2?
Answer:
There are fewer oxygen atoms in the equation than hydrogen or carbon.
Explanation:
PLATO
There is a dual equilibrium between the indicator methyl orange (Hln/In-) and acetic acid HC2H3O2(aq) and acetate NaC2H3O2. The acetic acid/sodium acetate equilibrium is:
HC2H3O2(aq)+ H2O(l) ⇌ C2H3O- (aq) + H3O+(aq)
a. How will the addition of acid (H3O+) affect this equilibrium? Explain in words how this changes the concentration of any reactants or products and then draw an arrow to show if the equilibrium shifts to the right or left.
b. How will the addition of sodium acetate NaC,H,O2 (aq) affect this equilibrium? Explain in words how this changes the concentration of any reactants or products and then draw an arrow to show if the equilibrium shifts to the right or left.
Answer:
a. Equilibrium shifts to the left.
b. Equilibrium shifts to the left.
Explanation:
Hello.
a. In this case, considering the Le Chatelier's principle which states that the addition of any product shifts the reaction towards the reactants in order to reestablish equilibrium, by the addition of H₃O⁺ we are adding a product, it means that the equilibriums shifts to the left.
b. In this case, since the addition of sodium acetate releases sodium ions and acetate ions, because it is totally ionized, such released acetate ions have the capacity to shift the equilibrium to left as it is a product as well as the H₃O⁺, therefore, adding sodium acetate shifts the equilibrium to the left, by also considering the Le Chatelier's principle.
Best regards!
please help it's already past due
Answer:
4 nitrogen, 2 oxygen, 2 nitrous oxide
An atom of aluminum loses how many electrons when it forms ionic bonds with three atoms of fluorine?
A. 1
B. 2
C. 3
D. 4
help pls i’ll give brainlest if it’s correct .
Answer:
A.) 64
Explanation:
The mass number is the number of protons and neutrons in the nucleus, so here there are 30 protons, and 34 neutrons, so the mass number is 64
In a chemical reaction is a new substance obtained? Explain your answer
0.158g of barium halide is completely reacted with H2So4 and 0.124g of BaSO4 is collected. Whats the identity of X for this barium halide
Answer:
BaBr(2)
Explanation:
See attachment
A chemical reaction that has the general formula of AB → A + B is best classified as a ________ reaction.
A:synthasis
B:polymeritzation
C:decomposition
D:oxidation
E:replacement
Answer:
b
Explanation:
Can someone help me please
Answer:
6 Protons 8 Neutrons 4 Electrons
Explanation:
PLEASE HELP!!!
Hydrogen and oxygen react to form water. At an atomic level, how do we know that a chemical reaction has occurred? *
1 point
Hydrogen molecules are negative, and oxygen positive.
For every oxygen atom, two hydrogen atoms are needed.
The hydrogen and oxygen atoms regroup into a new molecule.
Oxygen atoms are much larger than hydrogen atoms.
Answer:
Explanation:
The hydrogen and oxygen atoms regroup into a new molecule.
Look into intermolecular forces! :) it will show you different types of bonding/how molecules will bond
We know that a chemical reaction has taken place because hydrogen and oxygen atoms regroup into a new molecule.
A chemical reaction is said to have occurred when there is a rearrangement of atoms in two or more substances. This rearrangement of atoms often leads to the formation of a new substance.
At an atomic level, when hydrogen and oxygen react, we know that a chemical reaction has taken place because hydrogen and oxygen atoms regroup into a new molecule.
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why is there no such thing as single ionic molecule