Open Ended
21. What does it mean to say that "atoms are not created or destroyed" in a chemical reaction?
22. In a chemical reactičn, is it possible to change the amount of products by changing the
amount of reactants? Why?
23. Can atoms that are not in the reactants end up in the products of a chemical reaction? Why?
24. How would you prove that a chemical equation is balanced?
Answers
Answer:
Explanation:
21. Atoms are not created or destroyed means that atoms that you begin with are the atoms that you will end with. The catch is that the atoms will rearrange to give you new compounds, but the atoms that you initially had are the atoms you will still have after reaction. For eg, if you started with eggs and made omelet. Omelet is a "new" compound, but the atoms that were in the eggs have rearranged to become the omelet so can you see that atoms were not created or destroyed to make the omelet.
22. Yes because amount of products you make depends on how much reactants you have. For eg, I need two graham cracker(GC), one marshmallow(M), and one chocolate (C) to make a s'more. If I get more of each item then I can make more s'mores and consequently having minimum amounts results in less s'mores that I make.
23. Not possible, due to law of conservation of matter and energy. Atoms cannot be created nor be destroyed, they are simply rearranged. For eg, Taking A + B cannot give you a new compound with a chemical formula D or XZ. A + B can however give you AB which is rearrangement of the starting atoms.
24. Chemical equation is balanced when atoms on reactant side and atoms of product side are in equal counts. I have attached a graphic below for more help.
Related Questions
Which of these statements is true about heat?
Answers
Answer:
Explanation:
what are the statments i can't help till i have the posable answers
0.18 g of a divalent metal was completely dissolved in 250 cc of acidsolution containing 4.9 g H2SO4 per liter. 50 cc of theresidual acid solution required 20 cc of N/10 alkali forcomplete neutralization. Calculate the atomic weight of metal.
Answers
goodnight Gucci chunk cubic DDF if f Ch BK
What type of reaction is shown below?
H202 + H2O + O2
Single replacement
Combustion
Synthesis
Decomposition
Answers
Answer:
Decomposition Reaction
1. A(n) bond forms when one atom gives up one or more electrons to another atom. 2. Atoms or molecules with a net electric charge due to the loss or gain of one or more electrons are . 3. A(n) bond involves the sharing of electron pairs between atoms, also known as a molecular bond. 4. When one pair of electrons is shared between two atoms, a bond is formed. 5. When two pairs of electrons are shared between two atoms, a bond is formed. 6. A bond is a type of chemical bond where a pair of electrons is unequally shared between two atoms. As a result, one end of the molecule has a slightly negative charge and the other a slightly positive charge.
Answers
Answer:
For 1: Ionic
For 2: Ions
For 3: Covalent
For 4: Single
For 5: Double
For 6: Polar
Explanation:
For 1:An ionic compound is formed when the complete transfer of electrons takes place from one element usually, metals (forming cation) to another element usually, non-metals (forming anions).
Hence, an ionic bond forms when one atom gives up one or more electrons to another atom
For 2:An ion is formed when an element loses or gains an electron. Two types of ions are formed which are cations and anions.
Hence, atoms or molecules with a net electric charge due to the loss or gain of one or more electrons are ions.
For 3:A covalent bond is defined as the bond which is formed by the sharing of electrons between two atoms.
Hence, a covalent bond involves sharing electron pairs between atoms, also known as a molecular bond.
For 4:A single bond is defined as the bond in which 1 bond is present between the two atoms or 1 pair of electrons (two electrons) are shared between the atoms.
Hence, when one pair of electrons is shared between two atoms, a single bond is formed.
For 5:A double bond is defined as the bond in which 2 bonds are present between the two atoms or 2 pairs of electrons (four electrons) are shared between the atoms.
Hence, when two pairs of electrons are shared between two atoms, a double bond is formed
For 6:A polar bond is defined as the bond where unequal sharing of electrons takes place. This creates a dipole within a molecule.
Hence, a polar bond is a type of chemical bond where a pair of electrons is unequally shared between two atoms.
Which of the following are examples of electromagnetic waves?
A.thunder, singing, tsunamis
B.sound, tsunamis, earthquakes
C.light, microwaves, radiation
Answers
Answer:
C
Explanation:
Electromagnetic waves travel at the speed of light and do not require molecules (gas, solid or liquid) to vibrate and travel.
Soundwaves when singing or from thunder vibrate particles to reach our ears and are known as mechanical waves.
A se ion has a mass number of 77
and a charge of −2
. Determine the number of neutrons, protons, and electrons in this ion.
Answers
Answer:
1. Neutron number = 43
2. Proton number = 34
3. Electron number = 36
Explanation:
From the question given above, the following data were obtained:
Mass number = 77
Charge of ion = –2
1. Determination of the number of neutron.
Mass number of Se = 77
Atomic number = 34
Neutron number =?
NOTE: Atomic number = proton number
Mass number = Proton + Neutron
77 = 34 + Neutron
Collect like terms
77 – 34 = Neutron
Neutron number = 43
2. Determination of the proton number.
The atomic number of an element is simply defined as the number of protons in the atom of the element. Mathematically,
Atomic number = Proton number
Atomic number of Se = 34
Therefore, the proton number of Se²¯ is 34.
NOTE: The atomic number does not change be it atom, ion or molecule. It remains the same.
3. Determination of electron number.
Charge of ion = –2
Proton number = 34
Electron number =?
Proton – Electron = Charge
34 – Electron = –2
Rearrange
34 + 2 = Electron
36 = Electron
Electron number = 36
There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.
Explanation:
Given:
A selenium ion with a mass number of 77 and a charge of (-2).
To find:
The number of neutrons, protons, and electrons in selenium ion
Solution:
Charge on the selenium ion = -2
The atomic number of selenium = 34
Number of protons = Atomic number
Number of protons in selenium atom = 34
Number of protons in selenium ion = 34
Number of electrons in selenium atom = 34
Number of electrons in selenium ion= 34+2 = 36
(anion is formed by gaining of electrons that is why adding two electrons )
The mass number of selenium = 77
Mass number = Number of protons + Number of neutrons
77 = 34 + Number of neutrons in selenium
Number of neutrons in selenium ion = 77 - 34 = 43
There are 43 neutrons, 34 protons, and 36 electrons in the given selenium ion with a (-2) charge.
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SOMEONE HELP ASAP I NEED TO FIND AN ANSWER
Answers
Answer:
A) Q + XZ = X + QZ is a single displacement reaction.
B) Q + Z = QZ is a synthesis reaction
C) QT = Q + T is a decomposition reaction
D) QT + XZ = QZ + XT is double replacement reaction.
Explanation:
A) Q + XZ = X + QZ
This is a single displacement reaction because it is one in which one element is substituted for another one in a compound. In this case X is substituted for Q.
B) Q + Z = QZ
This is a synthesis reaction because Q and z combine to form a single product QZ.
C) QT = Q + T
This is a decomposition reaction because the compound QT breaks down to form 2 simpler substances Q and T.
D) QT + XZ = QZ + XT
Thus is a double replacement reaction because QT and XZ have exchanged cations to form new compounds QZ and XT
By referring to the particulate theory of mater, explain the following statement: Oxygen gas is very easy to compress when pressure is applied
By referring to the particulate theory of matter, explain the following statement: A solid lump of iron has a high density .
Answers
Answer:
See explanation
Explanation:
According to the particulate theory of matter, gas particles do not interact with each other. A gas is composed of isolated particles moving at high velocities and collide frequently with each other and the walls of the container.
Since the particles of a gas are mostly isolated, it is easy to compress the gas when pressure is applied thereby bringing the gas particles closer together.
On the other hand, in the solid state, the particles that compose matter are close together. These particles only vibrate about their mean positions due to strong intermolecular interaction between particles. The fact that the particles of the solid ion are so close together makes the solid iron lump to possess high density.
Nombra cada uno de los siguientes hidrocarburos de acuerdo a las reglas de la IUPAC
Answers
Answer:
i) ciclobutano
ii) 3-etil-4-metil ciclopenteno
Explanation:
Toda la idea de la nomenclatura IUPAC es permitir que la estructura de la sustancia se derive de su nombre y viceversa.
La nomenclatura IUPAC es un sistema universalmente aceptado para nombrar compuestos químicos.
los nombres de los compuestos enumerados son;
i) ciclobutano
ii) 3-etil-4-metil ciclopenteno
A hydrocarbon was found to contain 82.8% by mass of carbon. It has
an Mr of 58. Find the empirical and molecular formulas of this
compound.
Answers
Answer: C4H10
Explanation: [tex]\left \{ {{12x+y=58} \atop {\frac{12x}{58} =82,8%}} \right. \\[/tex]%
==> x=4, y=10 C4H10
17. (1.09 x 102) x (2.79 x 10')
18. (5.75 x 104) / (4.71 102)
19.(3.38 x 106) x (7.80 x 104)
20. (7.04 x 10) / (9.45 x 10-)
Answers
Answer:
17. 3,101.922
18. 1.2447441822
19. 288,057.12
20. 0.74497354
What type of nuclear decay is shown by the reaction below?
A. Alpha
B. Gamma
C. Beta
O D. Fission
Answers
Answer:
C. Beta
Explanation:
Which reaction occurs at the cathode of a galvanic cell that has an aluminum electrode in an electrolyte with aluminum ions and copper electrode in an electrolyte with copper ions ? The reduction potential for the reduction of Cu^ 2+ = 0.34 The reduction potential for the reduction of AP^ 3+ =-1.68V.
Answers
Answer:
[tex]{ \bf{Cu {}^{2 + } + 2e \: → \: Cu }}[/tex]
The reaction that occurs at the cathode of a given galvanic cell is:
Cu²⁺ + 2e⁻ → Cu
What is Galvanic Cell?A galvanic cell can be defined as an electrochemical cell that converts the chemical energy of spontaneous redox reactions into electrical energy. The galvanic cell makes use of chemical reactions to generate electrical energy.
A galvanic cell consists of two half-cells and a salt bridge. Each half-cell further contains an electrode dipped into an electrolyte. When both electrodes are dipped in the same electrolyte, then there is no need for a salt bridge.
At the anode, an oxidation reaction occurs at this electrode. At the cathode, reduction occurs at this electrode. The anode has a negative potential with respect to the solution while the cathode has a positive potential with respect to the solution.
As in the question, the reduction of Cu²⁺ has a positive reduction potential. Therefore, the reduction of the copper will occur at the cathode.
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A cart accelerating slower when mass was increased.
1st Law - 3rd Law
Answers
Answer:
Newton's second law
Explanation:
It is mentioning acceleration and mass
Newton's second law's equation = F = m*a
Hope u understood
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Our solar system is more than _________ in diameter.
Answers
Answer: 287.46 billion km
Explanation: calculated it myself. nah but thats the answer
in which of the following type of colloid, the physical state of dispersed phase and dispersion medium is same?
Gel
Foam
Emulsion
Aerosol
Answers
Answer:
Emulsion
Explanation:
According to Oxford dictionary, a colloid is, ''a homogeneous non-crystalline substance consisting of large molecules or ultramicroscopic particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle, and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.''
An emulsion is a dispersion of a liquid in a liquid. This means that the the physical state of dispersed phase and dispersion medium is same.
Examples of emulsions include; Vinaigrette, homogenized milk and hair cream.
PLEASE ANYONE HELP!!!
How does an increase in -CH2 groups in an organic chain affect the boiling point?
A. The boiling point increases as more -CH2 groups are added.
B. The boiling point increases up to 4 CH2 groups and then begins to decrease.
C. The boiling point is not affected by -CH2 groups, only by functional groups.
D. The boiling point decreases as more -CH2 groups are added.
Answers
Answer:
I believe it's a.
Explanation:
Which best describes a mixture?
It has a single composition, and it has a set of characteristics that does not change.
O It can have different compositions, but it has a set of characteristics that does not change.
O It has a single composition, but it has a set of characteristics that does change.
It can have different compositions, and it has a set of characteristics that does change.
Mark this and return
Save and yit
Answers
Answer:
I think the answer would be b, sorry if I'm wrong(EDIT: ITS ACTUALLY AAAAA)
The body's reaction to a change in the environment is called a response.
Please select the best answer from the choices provided
OT
OF
Answers
304 cm x m and 67kg to gram please helpppp!!!!!!!!
Answers
67kg= 67000g
Answer:
[tex]304cm = 3.04m \\ 67kg = 67000g[/tex]
Explanation:
[tex]100cm \: = 1m \\ 304cm = x \\ use \: \: cross \: multipication \\ 100x = 304 \\ \frac{100x}{100} = \frac{304}{100} \\ x = 3.04m[/tex]
-------------------------------------------------
[tex]1kg = 1000g \\ 67kg = x \\ \\ use \: cross \: \: multipication \\ 1x = 67 \times 1000 \\ x = 67000g[/tex]
Hope this helps
Have a nice day!
what type of chemical is manganese(IV) oxide
Answers
Answer:
catalyst
Explanation:
it alters the speed of reaction
what are the difference between ionic bond and covalent bond?
Which is stronger?
Answers
QUËSTIONS :- what are the difference between ionic bond and covalent bond?
IONIC BONDS :- THEY R BONDS WHICH R FORMED DUE TO THE COMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS
COVALENT BONDS :- THEY R THE BONDS WHICH R FORMED DUE TO INCOMPLETE TRANSFER OF ELECTRONS BETWEEN TWO ATOMS
IONIC BONDS R MORE STRONGER.
Explanation:
Ionic bond is much stronger than covalent bond because it involves complete transfer of electrons because of which there is formation of cation and anion and there exist huge electrostatic forces of attraction. They also have high melting and boiling point which proves that the ionic bond is very strong.
Differences between ionic bond and covalent bond :
Ionic Bonds. Covalent Bonds
Polarity :High. Low
Shape : No definite shape. Definite shape
Melting Point :High Low
Boiling Point: High Low
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on which factor?
Answers
Answer:
Temperature.
Explanation:
Kinetic molecular theory of gases states that gas particles exhibit a perfectly elastic collision and are constantly in motion.
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on temperature.
This ultimately implies that, the average kinetic energy of gas particles is directly proportional to the absolute temperature of an ideal gas. Thus, an increase in the average kinetic energy of gas particles would cause an increase in the absolute temperature of an ideal gas.
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
Roundup, a herbicide manufactured by Monsanto, has the formula C3H8NO5P. How many moles of molecules are there in a 647.3-g sample of Roundup?
I got the answer 2.305 x 10^24 but for some reason it’s not working. Is it the wrong one?
Answers
Answer:
3.830177515 moles
Explanation:
You have :
647.3 g of RoundupMolar mass of Round up which is equal to 169 g.moland the formula: n=m/MTherefore: n=647.3/169
=3.830177515 moles
Equal mases of ethane and hydrogen are mixed in an empty container at 25 degree celcius.The fraction of the total pressure exerted by hydrogen is
Answers
Answer:
15/16
Explanation:
We need to find the number of moles of hydrogen and number of moles of ethane present.
Since we have the same mass, m for both substances, the number of moles of hydrogen, n = m/M where M = molar mass of hydrogen molecule
Since hydrogen is H₂, M = 2 × 1 g/mol = 2 × 1 g/mol = 2 mol.
n = m/M
n = m/2
Also, number of moles of ethane, n' = m/M' where M' = molar mass of ethane.
Since ethane is C₂H₆, M' = 2 × 12 g/mol + 6 × 1 g/mol = 24 g/mol + 6 g/mol = 30 g/mol
n' = m/M'
n' = m/30
The total number of moles of gas present is thus n" = n + n' = m/2 + m/30 = (15m + m)/30 = 16m/30
The mole fraction of hydrogen is thus number of moles of hydrogen/total number of moles = n/n" = m/2 ÷ 16m/30 = m/2 × 30/16m = 15/16
Also, since the partial pressure due to hydrogen, P = mole fraction × total pressure, P'
P/P' = mole fraction = 15/16
So, The fraction of the total pressure exerted by hydrogen is 15/16
How many liters does 3 moles of Oxygen gas occupy at standard temperature and pressure
Answers
Answer: 3 moles of oxygen at STP will occupy a volume of 3×22. 4=67. 2 L.
Select the correct answer.
A sample taken from a layer of mica in a canyon has 2.10 grams of potassium-40. A test reveals it to be 2.6 billion years old. How much
potassium-40 was in the sample originally if the half-life of potassium-40 is 1.3 billion years?
O A.
4.20 g
O B.
8.40 g
O C.
12.6 g
• D.
16.8 g
O E.
25.2 g
Answers
Answer:
8.36 g
Explanation:
From;
0.693/t1/2 = 2.303/t log (No/N)
t1/2 = half life of potassium-40
t = age of the sample
No= initial amount of the sample
N= amount of the sample at time t
Substituting values;
0.693/1.3 × 10^9 = 2.303/2.6 × 10^9 log (No/2.10)
5.33 × 10^-10 = 8.86 × 10^-10 log (No/2.10)
5.33 × 10^-10/8.86 × 10^-10 = log (No/2.10)
0.6 = log (No/2.10)
Antilog (0.6) = (No/2.10)
No = 2.10 × Antilog (0.6)
No= 8.36 g
Explain and describe how the photoelectric effect occurs on an atomic level in terms of protons, neutrons, and electrons
Answers
ANSWER:
Explaining the experiments on the photoelectric effect. How these experiments led to the idea if light behaving as a particle of energy called a photon.
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Pls Answer
What happens when dilute sulphuric acid is poured on a copper plate ?
Answers
Answer:
No observable change.
Explanation:
Copper renders dilute sulphuric acid passive, no reaction.
H2SO4+Cu-->CuSO4+H2
Explanation:
THIS IS THE CORRECT ANSWER
What is a reaction rate
Answers
Answer:
Explanation:
A reaction rate is the measure of the change in concentration of the disappearance of reactants or the change in concentration of the appearance of products per unit time
