Consider the following reaction:
Mg + 2H2O Mg(OH)2 + H2 ΔH = -353 kJ
This reaction is
A.
exothermic because heat is released.
B.
endothermic because heat is released.
C.
endothermic because heat is absorbed.
D.
exothermic because heat is absorbed.
Answer:
A
Explanation:
I think it's the answer
The reactant side of a balanced chemical equation is shown below,
PC15 + 4H20 →
How many hydrogen atoms should there be on the product side in the equation? (5 points)
8
6
4
2
Answer:
do u still need the answer..
Explanation:
which of the following is a pure substance that contains two or more elements?
Answer:
pure substance does not contain two or more elements
Describe how this instrument works.
(legit this is 100pts so uhh help)
Operation
Answer:
This is a reflector telescope and in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.
Hope this helps!
Explanation:
Answer:
This is a reflector telescope and in which it captures different wavelengths of light and it hits one mirror, bounces back and hits another and then is shown through the eyepiece. It captures all of the visible spectrum and some areas above and below it. These telescopes are better for seeing big picture and not the fine details in planets surfaces.
Hope this helps!
Explanation:
Which statement best describes what happens to the stability of hydrogen and oxygen atoms when they form bonds in a water molecule?
Answer:
It's c
Explanation:
Because I've checked
State of Matter refers to _______.
Answer:
matter refers to anything that has mass and volume which occupies space
I need help ASAP my final 20 points!!!
Normal human sex cells have 23 chromosomes. Use the art to determine the number of chromosomes a sex cell may have if the nondisjuction occured during Meiosis I. Include all possible chromosome totals.
Answer:
46.....................
Explain what happens to water during electrolysis. Is this a chemical reaction or phase change?
By definition, electrolysis is the use of an electric current to cause a chemical reaction which wouldn't otherwise happen. In a chemical change, bonds are either broken or formed. Electrolysis is a chemical change because, in the process of electrolysis, bonds are broken or formed.
1. In drawing Lewis structures, a single line (single bond) between two elements represents: ? a shared electron B. ? B 2 a shared pair of electrons c. ? an octet of electrons D. ? an unshared pair of electrons
Answer:
B a shared pair of electrons (2)
Explanation:
In Lewis structures, a single line represents a single pair of electrons. This means that the elements share 2 electrons or one pair of electrons
Hope this helps!
The shared electrons behave as if they belong to both atoms in the bond and bind the two atoms together to form a molecule. The shared electrons are typically depicted as a line (—) connecting the bonded atoms. (A line in a Lewis structure represents two electrons. Therefore, option A is correct.
What is lewis structure ?Lewis structures, also known as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, are diagrams that depict the bonding between atoms in a molecule as well as any lone pairs of electrons that may exist.
A Lewis structure is based on the octet rule, which states that atoms share electrons in order for each atom to have eight electrons in its outer shell. An oxygen atom, for example, has six electrons in its outer shell.
Gilbert N. Lewis, who introduced the Lewis structure in his 1916 article The Atom and the Molecule, was named after it. Lewis structures expand on the electron dot diagram concept by adding lines between atoms to represent shared pairs.
Thus, option A is correct.
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Which of the following is not an alteration of a document?
additions
obliteration
erasure
O all of these answers
charring
None of these answers
ill give brainley
The science of measuring chemicals that go into and come out of a reaction is called
O meteorology
O atomic mass measuring
O molar metrology
o stoichiometry
Answer:
I think it is stoichiometry
Use this oxidation-reduction reaction to answer questions about half-reactions:
Upper m g plus 2 upper H upper C l right arrow upper M g upper C l subscript 2 plus upper H subscript 2.
Classify these half-reactions by typing in “O” for “oxidation half-reaction,” “R” for “reduction half- reaction,” and “N” for “neither.”
Answer:
For those who need it, the answers are N, O, R
Explanation:
To solve such this we must know the concept of redox reaction. Therefore, the given reaction is an oxidation and reduction reaction. The oxidation reaction is Mg [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] and reduction reaction is HCl [tex]\rightarrow[/tex] H[tex]_2[/tex] .
What is chemical reaction?Chemical reaction is a process in which two or more than two molecules collide in right orientation and energy to form a new chemical compound. The mass of the overall reaction should be conserved. There are so many types of chemical reaction reaction like combination reaction, double displacement reaction.
Redox reaction is a chemical reaction where oxidation and reduction takes place simultaneously. Oxidation is loss of electrons and reduction is gain of electrons. The electron transfer from oxidant to reductant.
Mg + 2HCl [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] + H[tex]_2[/tex]
Mg [tex]\rightarrow[/tex] MgCl[tex]_2[/tex] O
HCl [tex]\rightarrow[/tex] H[tex]_2[/tex] R
Therefore, the given reaction is an oxidation and reduction reaction.
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which pair of atoms constitutes a pair of isotopes of the same element?
Answer:
element with same number of protons but different number of neutrons
brainliest plzzzzz
11. The ease with which water can pass
through a rock or sediment is called
a. permeability c. porosity.
b. carbonation. d. velocity
Answer:
It's option a) Permeability.
Identify the limiting reactant when 9.65-g H2SO4 reacts with 6.10-g of NaOH.
Answer:
3.56
Explanation:
can someone please explain how to find an emperical formula given mass not percentage?
Answer:
1. Get the mass of each element by assuming a certain overall mass for the sample (100 g is a good mass to assume when working with percentages). ...
2. Convert the mass of each element to moles. ...
3. Find the ratio of the moles of each element. ..
4. Use the mole ratio to write the empirical fomula
Answer:
Multiply each result by the given mass.
Explanation:
Hi!
In order to find percent/mass composition you would
1. write the formula
2. calculate the molar mass for each equation
3. add all the masses to get the compound molar mass
4. divide each molar mass by the total mass
and then for mass composition, you would multiple eachy result by the given mass.
For example;
Calculate the number of grams of gold in 89.6 grams of gold(1) perchlorate.
Your formula would be AuClo4
Au : 196.96 x 1
Cl: 35.4 x 1
O: 16 x 4
Add the masses together to get 296.5 g/mol
Lets say we're looking for Oxygen. You would take what you got (16 x 4) and divide it by the total mass. 64/296.5
This would equal 0.215. Instead of multiplying this by 100 like you would for percent, for mass you would multiply by what is given. in this instance it is 89.6.
0.215 x 89.6 = 19
But the question is asking for gold,
197/296
= 0.664 x 89.6
= 59.5
Your answer would be 59.5 grams Au
Hope this helped! : D
It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reaction:
2 NaOH + H2CO3 → Na2CO3 + 2 H2O
The concentration of the carbonic acid is _____.
It requires 60 mL of 0.20 M sodium hydroxide [tex](NaOH)[/tex] to neutralize 25 mL of carbonic acid [tex](H_2CO_3)[/tex], hence the carbonate ions concentration is [tex]0.24M[/tex].
Given:
Reaction:
[tex]\to \bold{2NaOH + H_2CO_3 \to Na_2CO_3 + 2H_20 }[/tex]
[tex]NaOH[/tex] volume [tex](V_B) = 60 \ ml[/tex]
[tex]H_2CO_3[/tex] Volume [tex](V_A) = 25\ ml[/tex]
[tex]NaOH[/tex] Molarity [tex](C_B) = 0.20\ M[/tex]
[tex]H_2CO_3[/tex] moles [tex](n_A) = 1[/tex]
[tex]NaOH[/tex] moles [tex](n_B) = 2[/tex]
To find:
[tex]H_2CO_3[/tex] Molarity [tex](C_A) =?[/tex]
Solution:
Using the neutralization reaction:
[tex]\to \frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B} \\\\[/tex]
[tex]\to C_B = 0.2\ M \\\\ \to n_A = 1 \\\\ \to n_B = 2 \\\\ \to V_B = 60\ ml \\\\ \to V_A = 25\ ml[/tex]
Calculating the [tex]C_A[/tex]:
[tex]\to \frac{C_A \times 25}{0.2 \times 60} =\frac{1}{2} \\\\\to C_A =\frac{1 \times 0.2 \times 60}{2 \times 25} \\\\\to C_A =\frac{1 \times 2 \times 12}{2 \times 5 \times 10} \\\\ \to C_A =\frac{ 12}{ 5 \times 10} \\\\\to C_A = \frac{6}{5 \times 5} \\\\\to C_A = \frac{6}{25} \\\\\to C_A=0.24\ M[/tex]
Therefore, the concentration of carbonic acid is "0.24M".
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The concentration of carbonic acid( H₂CO₃) is 0.24 M.
The given reaction:
2 NaOH + H₂CO₃ → Na₂CO₃ + 2H₂O
Volume of NaOH = 60mL
Volume of H₂CO₃ = 25 mL
Molarity of NaOH= 0.20M
To find:
Molarity of H₂CO₃=?
2 moles of NaOH and 1 mol of H₂CO₃ reacts to give 1 mol of Na₂CO₃.
Using the neutralization reaction:
Consider A to be NaOH and B to be H₂CO₃
[tex]\frac{\text{Number of moles of A}}{\text{Number of moles of B}} =\frac{\text{Molarity of A*Volume of A}}{\text{Molarity of B*Volume of B}}[/tex]
On substituting the values in order to calculate molarity of H₂CO₃:
[tex]\text{Molarity of B}=\frac{1*0.2*60}{2*25} \\\\\text{Molarity of B}=0.24M[/tex]
Therefore, the concentration of H₂CO₃ is 0.24 M.
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which two observers would be experiencing the same apparent solar time?
The observers which would experience the same apparent solar time are observer B and observer E. This means the correct response as per the full question indicated in the attached document is number 2.
Types of Solar TimeThere are two types of Solar Time. They are:
Apparent Solar Time and Mean Solar TimeWhat is Apparent Solar Time?Apparent solar time refers to the time of the day that is shown by the hour angle of the sun. It is also defined as the sun's position in the sky going by direct observation. Direction observation of the sun to determine Solar Time is possible using a Sundial.
See the link below for more about Apparent Solar Time:
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when an electron is acquired by a neutral atom, the energy change is called
Answer:
when an electron is acquired by a neutron atom, the energy change is called its electron affinity
When an electron is added to a neutral atom to create a negative ion, the energy of the atom changes (in kJ/mole). This is how electron affinity is defined. Alternatively put, the possibility of the neutral atom receiving an electron.
What is electron affinity ?The amount of energy released when an electron binds to a neutral atom or molecule in the gaseous state to produce an anion is known as the electron affinity of an atom or molecule.
Although there is a slight distinction between the two, electron gain enthalpy is occasionally also referred to as electron affinity. The amount of energy released when an electron is added to a single gaseous atom is known as the electron gain enthalpy.
The amount of energy released when an atom receives an additional electron is known as its electron affinity. The gaseous state is when electron affinities are measured. On the periodic table, electron affinities tend to shift from negative to positive as we move from left to right.
Thus, when an electron is acquired by a neutral atom, the energy change is called as electron affinity.
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15 POINTS AND BRAINLIEST
Martin hooked up the following circuit. He noticed that the light did not turn on. How could he fix the circuit to make it work?
A. Martin needs to have one wire coming from one side of the battery to the light bulb and one wire coming from the other side to the switch. To make a closed circuit, he can use a wire to connect the switch to the light bulb.
B. Martin needs to connect one wire from the switch to the battery and one wire from the battery to the light bulb. When he does this, it will be a closed circuit that allows electricity to flow.
C. Martin needs to turn the battery around. When he does this, it will become a closed circuit allowing electricity to flow through the circuit in a loop.
D. The switch is in the open position. If Martin lifts the switch, it will close the circuit and electricity will flow from the battery to the light bulb in a loop.
Question 17(Multiple Choice Worth 2 points)
(07.01 MC)
Answer: maybe D sorry if it's wrong
Explanation:
Helppp plzzzz!!!!!!1Asappppp
Answer:
0.178M
Explanation:
The question can immediately be understood as comparing two states.
- The initial state M1 , V1.
- The Final state M2 , V2.
M - Molarity.
V - Volume (in mili liters/ml/ in this case).
The formula is stated as:
M1 * V1 = M2 * V2
Given- Required
M1 = 0.125M V1 = 265ml M2 = ?
V2 = 186ml
Plug these values into the formula above and divide V2 to get M2.rearranged formula - M2 = M1 * V1 / V2 = 0.125M * 265ml / 186ml
= 0.178091397 M ~ ~ 0.178M.
how to tell if an electron will make a cation or anion
Complex organisms require a large number of cells that
A.Complex organisms require a large number of cells that
Astatine-218 has a half-life of 1.6 seconds. If you begin with a 1.7 g sample of astatine-218, how much of the sample remains after 3.2 seconds?
Answer:
do you still need help on this question
Explanation:
What is true about Carbon-14 and Carbon-12?
a. The mass of the Carbon-14 sample is less than the Carbon-12 sample, but the reactivity of both samples was the same.
b. The mass of the Carbon-14 sample is greater than the Carbon-12 sample, but the reactivity of both samples was the same .
c. The reactivity of the Carbon-14 sample is less than the Carbon-12 sample, but the mass of both samples was the same.
d. The reactivity of the Carbon-14 sample is greater than the Carbon-12 sample, but the mass of both samples was the same.
Answer:
B.
Explanation:
Correct: b. The mass of the Carbon-14 sample is greater than the Carbon-12 sample, but the reactivity of both samples was the same .
- C-14 has two additional neutrons, so is heavier than C-12. The chemical properties will be the same, however.
Why are earthworms called as “friends of farmers”? Answer in no less than 4 sentences
Answer:
Organic matter composted with earthworms, often known as vermicompost, has been demonstrated in studies to have disease-suppressing qualities. The earthworms loosen the soil and enrich it with humus. As a result, they are known as farmer's pals. They help the crops grow healthier and over the time have earned farmers trust.
Explanation:
Hope this helps in some way!
Give braniliness
AH = ?
Select one:
O a. Hproducts/Hreactants
O b. products-Hreactants
O c. Hreactants+H products
O d. Hreactants-Hproducts
Answer:
I think its C
Explanation:
How many grams of ammonia are produced from 6 moles of nitrogen?
A small container of perfume is opened in a classroom. Soon every student in the room smells the perfume. Explain this in terms of molecules.
When perfume or cologne is sprayed into the air, it turns into a gas and its particles mix with other air particles that quickly move around the room. This is because gas is the least dense of the three states of matter. It moves quickly into any space or volume because it has the least density. This is called diffusion, when molecules or particles move from areas with high concentration to low concentration areas.