Answer:
a. Endothermic
b. 26.37kJ/mol
Explanation:
a. As we can see, the temperature of the water is decreasing when the reaction is occurring, that means the reaction is absorbing heat and is endothermic
b. To find the enthalpy we must find the change in heat when 12.1g of KCl are dissolved. Using the equation:
Q = -m*ΔT*C
Where Q is change in heat
m the mass of solution (250g + 12.1g = 262.1g)
ΔT is change in heat (17.1°C - 21.0°C = -3.9°C)
And C is specific heat of the solution (4.184J/g°C assuming is the same than the specific heat of water).
Replacing:
Q = -262.1g*-3.9°C*4.184J/g°C
Q = 4277J = 4.28kJ
As reaction enthalpy is the change in heat per mole of reaction, we must find the moles of 12.1g of KCl:
Moles KCl -Molar mass: 74.55g/mol-:
12.1g KCl * (1 mol / 74.55g) = 0.1623 moles KCl
The reaction enthalpy us:
4.28kJ / 0.1623mol = }
26.37kJ/mol
Name the following alkene compound
what does the picture depict about ecology?
In humans, normal color perception (N) dominates the expression of color blindness (n), and both of these genes are carried on the X chromosome (XN or Xn). A woman with normal color vision has a color-blind father. Her husband is also color-blind.
a. What is the genotype of the colorblind man? ____
b. What is the genotype of the woman? ______
c. What is the probability of her daughter to be colorblind? __________%
d. What is the probability of her sons to be colorblind? _________%
WHO CAN HELP ME
Answer:
a: Nn or XN
b: Nn or Xn
c: 75%
d: 50%
Explanation:
Which of the following methods is least likely to help Alisha determine the age of sedimentary rock layers in her backyard?
A. Apply radiometric dating to determine the amount of radioactive isotopes in each rock layer.
B.Identify index fossils in sedimentary rock that have lived in a particular time in Earth’s history.
C. Analyze seismic diagrams to determine how radioactive elements break down into stable elements.
D. Use relative dating techniques to determine how individual fossil groups are related to specific rock layers.
ILL GIVE BRAINLIEST!11
Answer:
i put c
Explanation:
Rocks' ages are determined through radiometric dating, which takes into account the ratio of two different isotopes in a sample. Geologists can use tools like these to assess the age of a material,Mass spectrometer for thermal ionization Thus, option C is correct.
What determine the age of sedimentary rock layers?How rocks are structured in strata and how they fit into the larger geological history are the main topics of stratigraphic study. This approach is best suited for studying sedimentary rocks. Cross dating is a method for using fossils to determine a rock's relative age.
Therefore, Index fossils are sought after by geologists in geological strata. Index fossils are useful because they show the relative dates of the rock layers in which they are discovered. Since radioactive isotopes deteriorate with known time intervals.
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If potassium reacts so dangerously with water, and people are mostly made of water, why can we eat bananas without blowing up?
Answer:
A banana, like most other lifeforms, is about 70% water, and all the potassium it contains already exists in the form of K+ ions dissolved in water. Which is why bananas do not explode in water, or spontaneously combust.
According to the tow of conservation of matter, we know that the total number of atoms does not change in a chemical reaction and thus mas is conserved This
is part of a chemical reaction hydrogen plus orygon yobis water Can you complete this moder? Reorganize the reactants in order to complete the productie
of the reaction
Your answer:
Answer:
no sé de eso perdón necesito los puntos
one reaction that produces hydrogen gas can be represented by the unbalanced chemical equation Mg(s)+HCI(aq) -> MgCI(aq)+H2(g). What is the mass of HCI is consumed by the reaction of 3.25 mol of magnesium?
128 g HCl
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to RightChemistry
Atomic Structure
Reading a Periodic TableStoichiometry
Reaction Mole RatiosUsing Dimensional AnalysisExplanation:Step 1: Define
[RxN - Unbalanced] Mg (s) + HCl (aq) → MgCl (aq) + H₂ (g)
↓
[RxN - Balanced] 2Mg (s) + 2HCl (aq) → 2MgCl (aq) + H₂ (g)
[Given] 3.25 mol Mg
[Solve] x g HCl
Step 2: Identify Conversions
[RxN] 2 mol Mg → 2 mol HCl
[PT] Molar Mass of H - 1.01 g/mol
[PT] Molar Mass of Cl - 35.45 g/mol
Molar Mass of HCl - 1.01 + 35.45 = 36.46 g/mol
Step 3: Stoich
[S - DA] Set up: [tex]\displaystyle 3.25 \ mol \ Mg(\frac{2 \ mol \ HCl}{2 \ mol \ Mg})(\frac{36.46 \ g \ HCl}{1 \ mol \ HCl})[/tex][S - DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 127.61 \ g \ HCl[/tex]Step 4: Check
Follow sig fig rules and round. We are given 3 sig figs.
127.61 g HCl ≈ 128 g HCl
Decide whether a chemical reaction happens in either of the following situations. If a reaction does happen, write the chemical equation for it. Be sure your chemical equation is balanced and has physical state symbols. situation chemical reaction.
A strip of solid magnesium metal is put into a beaker of 0.042M SnCl3 solution.
Answer: [tex]3Mg(s)+2SnCl_3(aq)\rightarrow 3MgCl_2(aq)+2Sn(s)[/tex]
Explanation:
Single replacement reaction is a chemical reaction in which more reactive element displaces the less reactive element from its salt solution.
A more reactive element is one which can easily lose or gain electrons as compared to the other element.
As Magnesium is more reactive than tin, it can easily displace tin from its salt solution [tex](SnCl_3)[/tex] and form magnesium chloride and tin in elemental form.
The balanced chemical equation is:
[tex]3Mg(s)+2SnCl_3(aq)\rightarrow 3MgCl_2(aq)+2Sn(s)[/tex]
which one is the correct ans.
Answer:
Aluminium Sulphate
Explanation:
Aluminium sulphate is the most widely used aluminium coagulant. It is soluble in water and used as a coagulating agent in purification of drinking water and in waste water treatment plants.
Answer:
where are you from .. ...
What is the formula for Triphosphorous nonaoxide
Describe the patterns and atomic mass is an ion charges in the periodic table
Answer:
The atomic number increases across a period and down the group or family. The atomic mass generally increases with atomic number with a few exceptions.
• as it sits on top of a building that is 50 meters tall.
• as it is half-way through a fall off a building that is 50 meters tall and travelling 19.8 meters per second.
• as it is just about to hit the ground from a fall off a building that is 50 meters tall and travelling 28 m/s
What is the potential energy of the ball as it is half-way through the fall (25 meters high)?
What is the atomic weight of Mercury?
Answer:
Not sure if I'm correct, but I think it's 200.59 u
Answer:
The answer is 200.59 u
Explanation:
Mercury has a mass of 3.3 x 1023kilograms. This mass is contained in a volume of 14.6 billion cubic miles (60.8 billion cubic km). The mass and volume of Mercury is only about 0.055 times that of Earth
The image shown here is a good illustration of which law?
Answer:
The answer is A.Newton's First law
A mixture of gaseous reactants is put into a cylinder, where a chemical reaction tums them into gaseous products. The cylinder has a piston that moves in or out, as necessary, to keep a constant pressure on the mixture of 1 atm. The cylinder is also submerged in a large insulated water bath. 1 atm pressure piston cylinder The temperature of the water bath is monitored, and it is determined from this data that 300.1J of heat flows out of the system during the reaction. The position of the piston is also monitored, and it is determined from this data that the system does 316.kJ of work on the piston during the reaction water bath gases exothermic.
Required:
a. Is the reaction exothermic or endothermic?
b. Does the temperature of the water bath go up or down?
Answer:
The reaction is exothermic
The temperature of the water bath goes up
Explanation:
An exothermic reaction is one in which energy flows out of the reaction system.
In this case, the system is the reaction vessel while the surrounding is the water bath. We see in the question that 300.1J of heat flows out of the system during the reaction. This is heat lost to the surroundings showing that the reaction is exothermic.
As energy is lost to the surroundings, the temperature of the water bath rises accordingly.
What would be the structural formula for sodium fluoride? (NaF)
Answer:
Formula and structure: The chemical formula of sodium fluoride is NaF and its molar mass is 41.99 g/mol. It is a simple ionic compound, made of the sodium (Na +) cation and fluoride (F -) anion. The solid salt exists as cubic crystals similar to the crystal structure of sodium chloride (NaCl).
Explanation:
The mass of a dust particle would be measured in?
Can you locate any mountains in the tropical zones?
Answer:
At even lower levels mountain lands grade into other types of landform and vegetation—e.g., tropical or temperate forest, savanna, scrubland, desert, or tundra. The largest and highest area of mountain lands occurs in the Himalaya -Tibet region; the longest nearly continuous mountain range is that along the west coast of the Americas from Alaska in the north to Chile in the south.
eh-
Explanation:
need help answering this, Aleks is very picky, and I have been struggling with these questions
Answer:
No
No
Yes 25cm
Explanation:
1) mass can't be divided by distance.
2) the measurements are completely different but under the same category of distance. you can only divide it if meters was cm and squared
3) measurements the same and you can multiply it
How can weak acids and weak bases cause pH stress to cells?
a. Weak bases will only cause pH stress at low pH.
b. If a cell has transporters that are not well regulated, weak acids or weak bases can accumulate inside the cells and cause stress.
c. Only weak acids can cause stress by diffusing across a membrane at low pH.
d. At certain pH levels, both weak acids or weak bases will be uncharged, and thus are small uncharged molecules that can diffuse across a membrane and cause pH stress inside the cell. e. Weak acids and weak bases do not cause stress.
Answer:
b
Explanation:
If a cell has transporters that are not well regulated, weak acids or weak bases can accumulate inside the cells and cause stress.
Which is an acceptable Lewis structure for a diatomic nitrogen molecule?
OA NEN
OB.
N
N
O C.
:N
N:
OD.
NEN
OENEN
Answer:
:N:::N:
Explanation: 10 valence electrons betwwen the 2
need an octet
and N needs 5 for a neutral formal charge
An acceptable Lewis structure for a diatomic nitrogen molecule is
:N:::N: .Option C is correct. This is further explained below.
What is Lewis structure for a diatomic nitrogen molecule?Lewis structure for a diatomic nitrogen molecule simply refers to the triple bond exists between two nitrogen atoms in the N2 Lewis structure.
In conclusion, The nitrogen molecule is diatomic, which means it is made up of two atoms of the same element.
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For case 1, what happens when an electron jumps from energy level 1 to energy level 3 in an atom?
Answer:
Case 1 (energy level): In an atom, an electron jumps from energy level 1 to energy level 3. ... The energy will increase.
Explanation:
what is the purpose of sand bath in preparation of ethane
Answer:
The sand bath spreads the heat out so that the flask is heated evenly. This reduces the chance of the flask breaking and ensures that there are no hot spots in the reaction mixture which could lead to excessive charring,
Explanation:
Which statement describes the movement of the medium by a transverse wave?
A. at an obtuse angle to the wave
B. parallel to the wave
C. at a right angle to the wave
D. at an acute angle to the wave
Answer:
A
Explanation:
But I'm not sure just my instinct
The statement that described the movement of the medium via the transverse wave should be that it should be parallel to the wave.
What is a transverse wave?It is the waves in which the motion considered all the points that should be on the wave oscillate along the paths at the right angles with respect to the wave of the direction. An example of this kind of wave should be electromagnetic, etc. Here, the movement should be parallel to the wave.
Hence, the correct option is b.
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Which of the following is true?
A)If we know that a reaction is an elementary reaction, then we know its rate law.
B)The rate-determining step of a reaction is the rate of the fastest elementary step of its mechanism.
C)Since intermediate compounds can be formed, the chemical equations for the elementary reactions in a multistep mechanism do not always have to add to give the chemical equation of the overall process.
D)In a reaction mechanism, an intermediate is identical to an activated complex.
E)all of these statements are true.
Answer:
If we know that a reaction is an elementary reaction, then we know its rate law.
Explanation:
An elementary reaction is a reaction that takes place in one reactive encounter. This means that the two species interact in a single step to give the products.
If two reactants interact in a single step to yield the products then we can easily deduce the rate law from the reaction equation.
For instance, For the reaction;
2A + B → C
The rate law is
rate = k[A]²[B].
If the reaction is an elementary reaction and the equation of the reaction is balanced, then we can deduce the rate law from the balanced reaction equation.
The three temperate marine climates are?
Marine west coast, humid subtropical, and Mediterranean.
An allergy medicine is usually stored in a cabinet at room termperature where its molecules move around each other. By
mistake, an intern transferred energy into the medicine. After one hour, the intern found the medicine and noticed that it
was a liquid. How were the molecules moving when the intern found the medicine? Explain why the molecules were
moving this way after the intern transferred energy ito the medicine.
Answer:
hello, can you pleas egive me the answer? i have the same exact question. thank you!
Explanation:
What is geberal formula for alkane?
Answer:
CnH2n+2
Explanation:
Alkane have double and two atoms of hydrogen than carbon atoms
Like C4H10
n = 4
CnH2n+2
C4H2×4+2
C4H10
on analysis an ammonium salt of an alkanoic acid gave 60.5% C and 6.5% H if 0.309g of the salt yield 0.0313g of Nitrogen determine the empirical formula of the salt [ H = 1, C =12, N = 14, O= 16]
Answer: C7H9NO2
Explanation:
%N = 0.0313/0.309 x 100
= 10.1%
%0 = 100 — (60.5 + 6.5 + 10.1)
= 22.9
C; 60.5/12 H; 6.5/1 N; 10.1/14 O; 22.9/16
C; 5.04/0.72 H; 6.5/0.72 N; 0.72/0.72 O; 1.43/0.72
Empirical formula — C7H9NO2
When two substances combine to form a mixture, the properties of the substances change. True False
Answer:
Tell students that sometimes when two (or more) substances are mixed together, a change occurs and another substance (or substances) is created. This is called a chemical reaction. Gas may form, heat may be produced, and color may change. These types of changes indicate that a chemical reaction has occurred.