Answer:
The enthalpy of reaction is -185 kJ
Explanation:
To get the reaction:
H₂(g) + Cl₂(g) → 2 HCl(g)
you must follow the following steps:
1) Reactive molecules must break their bonds to obtain their atoms.
H₂(g) → 2 H(g)
Cl₂(g) → 2 Cl(g)
Bond energy (or enthalpy) is the energy required to break one mole of bonds of a gaseous substance. In the case of diatomic molecules with a single bond, it corresponds to the energy necessary to dissociate 1 mole of said substance in the atoms that form it.
Whenever you want to break links you must supply energy, so the link enthalpy will have positive values; while when a mole of bonds is formed energy is released and the bond enthalpy of this process will be negative.
In this case you will then have:
H₂(g) → 2 H(g) ΔH=436 kJ/mol
Cl₂(g) → 2 Cl(g) ΔH=243 kJ/mol
So the total energy needed to break all the bonds is:
ΔH=1 mol*436 kJ/mol +1 mol* 243 kJ/mol= 679 kJ
2) The atoms that were obtained in the break of the bonds must be combined to obtain the product.
2 H (g) + 2 Cl (g) → 2 HCl (g)
Being the single bond energy for one mole of 431 kJ H-Cl bonds and considering that two moles of H-Cl bonds are formed, the ΔH is:
ΔH = -2 moles* (432 kJ/mol) = -864 kJ
As mentioned, when a mole of bonds is formed energy is released, the bond enthalpy of this process will be negative. So the formation of HCl is negative.
Hess's law states that the energy change in an overall chemical reaction is equal to the sum of the energy changes in the individual reactions comprising it. So:
ΔHtotal= -864 kJ + 679 kJ
ΔHtotal= -185 kJ
The enthalpy of reaction is -185 kJ
A climber is attached to a vertical rope that has a tension of 785 N. If the
climber has a mass of 85 kg, what is the net force on the climber?
O A. 48 N up
OB. 542 N up
O C. 700 N down
O D. 48 N down
SUBMIT
Answer:
D. 48 N down
Explanation:
Given that:
Mass of climber = 85 kg, Tension on rope = 785 N, acceleration due to gravity = 9.8 m/s²
To calculate the net force on the climber, we need to first calculate the weight of the climber. Since the climber is affected by the earth gravity, the weight of the climber is the product of his mass and the acceleration due to gravity, therefore:
Weight = mass × acceleration due to gravity = 85 kg × 9.8 m/s² = 833 N
The weight of the climber is acting downwards while tension on the rope is acting upwards, therefore:
Net force on the climber = 785 N - 833 N = - 48 N
This means that the net force on the climber is 48 N downwards
Answer:
48 N down
Explanation:
Ayepecks
I'm a scientist working on a very high-class operation in a classified area, we experienced some very strange encounters with the people we test on, like trying to bite us,attack us causing harm i think we discovered something.
Answer:
The most important first realization is to find out if the patients are deceased and their bodies are acting under an outside volition such as a virus reanimating the body through the use of the brain stem. If they are still living then they are what would be called infected if dead they are the undead naturally enough. Keep them contained as best you can but knowing scientists they will get free. When facing an infected they can die to any injuries that a normal human can they just won't react to pain so don't shoot for the head blast that thing in the chest then hit it in the head while it's down. Forget hand to hand combat or most close-ranged weapons unless absolutely necessary because close contact means exposure to fluids from the zombie they don't have to bite you to turn you. There is so much more to be said about this I recommend picking up the ZAS zombie survival book I recently got it and have not yet finished it but have learned a great deal.
Explanation:
Yes I fully understand this is not real and I simply felt like answering in a detailed manner for fun and that book is a serious recommendation.
Answer:
The most significant first acknowledgment is to see whether the patients are expired and their bodies are acting under an outside volition, for example, an infection vivifying the body using the cerebrum stem. On the off chance that they are as yet living, at that point they are what might be called tainted if dead they are the undead normally enough. Keep them contained as well as can be expected however knowing researchers they will get free. When confronting a tainted they can bite the dust to any wounds that an ordinary human can they just won't respond to torment so don't go for the head shoot that thing in the chest at that point hit it in the head while it's down. Disregard hand to hand battle or most close-extended weapons except if completely fundamental since close contact implies introduction to liquids from the zombie they don't need to nibble you to turn you. There is quite a lot more to be said about this I suggest getting the ZAS zombie endurance book I as of late got it and have not yet completed it yet have taken in a lot.
Explanation:
Smaller particles in an atom are called ____________.
Answer:
[tex]\large \boxed{\sf subatomic \ particles}[/tex]
Explanation:
The smaller particles in an atom are called subatomic particles. Subatomic particles include electrons, protons, and neutrons.
Calculate the pOH and pH of a solution which contains 0.001 M NaOH. Assume 100% ionization. (Need an in-depth explanation with formulas please)
Answer:
pH: 11
pOH: 3
Explanation:
NaOH is a strong base which means that it dissociates completely in water. It will break apart into Na⁺ and OH⁻ ions.
NaOH ⇒ Na⁺ + OH⁻
Because NaOH dissociates completely into its respective ions in water, the moles of NaOH is equal to the moles of hydroxide ions. So, [OH⁻] = 0.001 M.
Now to find the pOH, use the formula pOH = -log[OH⁻].
pOH = -log[OH⁻]
= -log(0.001)
= 3
The pOH of the solution is 3.
To find the pH, subtract the pOH from 14 since pH + pOH = 14.
14 - 3 = 11
The pH of the solution is 11.
Hope that helps.
according to Bohr atomic model
Answer:
A small positively charged nucleus surrounded by revolving negatively charged electrons in fixed orbits
25g ice crystals are taken in a beaker and inserted a thermo meter into it and slowly heated. Answer the following questions based on the above experiment.
a) At what temperature ice starts melting?
b) At 50 0 C is reached, what is the physical state of ice?
c) At 100 0 C is reached the boiling point of substance is not rising for some time. What is the reason for it?
d) What is the boiling point of the substance?
e) What is physical state of the substance above 100 degree C?
Answer:
a) 0°C
b) liquid
c) The energy supplied at 100°C is utilized in breaking the intermolecular forces in the liquid.
d) 100°C
e) gas
Explanation:
There are three States of matter; solid, liquid and gas. If we start heating 25g of ice in a beaker with a thermometer inserted into it, the ice will change from solid to liquid and finally to gas as the temperature increases.
At 0°C, the solid ice begins to melt and remains liquid between 0°C-100°C. This is called the liquid range of water. At 100°C, the heat supplied does not lead to further rise in temperature. The energy supplied is rather utilized in breaking the intermolecular forces in the liquid. This is known as the latent heat of vaporization. Above 100°C, the liquid is changed to vapour. Water vapour is commonly called steam.
The ability of a material to burn (its flammability) is an indication of the materials reactivity with oxygen. Does the information you found about flammability agree with the general trend that noble gases are fairly unreactive? Explain your answer
Answer:
Yes, this theory supports the inert nature of noble gases.
Explanation:
Noble gases already attain octet state stability, by having their outer shells completely filled with electrons. This makes them unable to take part in chemical reaction (by lose, gain or sharing of electrons).
Flammability occurs when matter burns through combination with oxygen, and changes to a different substance.
I hope this explanation is clear, let me know if I can be of further assistance.
Which of the mechanical waves below has the greatest energy?
Answer:
Blue wave.
Explanation:
The energy of a wave depends on its amplitude. A wave having more amplitude will have greatest energy while a wave having small amplitude will have least energy. The given figure shows four waves that are shown with green, orange, blue and red color. It is very clear from the figure that the amplitude of blue wave is greatest of all the wave.Hence, blue wave will have greatest energy.Which of the following phrases describes valence electrons?
O A. Electrons that are part of the core of the atom
O B. Electrons that are closest to the nucleus
O C. Electrons that are farthest from the nucleus
D. Electrons identified by the period number of the element
Answer:
C
Explanation:
because valence electrons are located at the last energy level
Element Grouping Quick Check:
1. Which element has two valence electrons?
D. calcium
2.Based on its position in the periodic table, which element would have seven valence electrons?
A. Chlorine
3. Which phrase describes a valence electron?
C. An electron in the outer energy level of an atom
4. Which phrase best describes a period on the periodic table?
A. A row of elements
5. Which two elements have the same number of energy levels with electrons in them?
A. Boron and Oxygen
Hope this helps!
A scuba diver’s air tank contains oxygen, helium, and nitrogen at a total pressure of 205 atmospheres. The partial pressure of nitrogen is 143 atmospheres, and the partial pressure of helium is 41 atmospheres. What is the partial pressure of oxygen in the tank?
answer is 20
explanation: total Pressure = 205
partial pressure of N = 143
partial pressure of He = 41
total pressure = partial pressure of N + partial pressure of O + partial pressure of He
partial pressure of O = 205 - 185 = 20
Answer:
20
Explanation:
Briefly explain how magnetic behavior is related to the arrangement of valence electrons in the outer orbitals
Answer:
Elements with unpaired valence electrons in the outer orbital are paramagnetic. Elements that are predicted to exhibit paramagnetic behavior may exhibit ferromagnetic behavior. Elements that contain only paired valence electrons are diamagnetic.
How much heat is needed to raise the temperature of water with mass of 27.0 g at 20.0°C to 45.0°C?
Answer:
2835 J
Explanation:
Take the specific heat capacity of water as 4.2 J/ g°C.
Energy (heat) = mass x specific heat capacity x change in temperature
(E= mcΔT)
E = 27 x 4.2 x (45-20)
E = 2835 J
What are indicators? How methyl orange and phenolphthalein changes their colour in acidic and basic solutions? How litmus paper changes its colour in different solutions?
Answer:
See the answer below
Explanation:
In chemistry, indicators are substances that are capable of changing colors with respect to the pH. Each indicator has its characteristic color in acidic pH and another characteristic color in alkaline pH.
Methyl orange indicator appears red in acidic solution and yellow in basic solutions. Phenolphthalein is usually colorless in acidic solutions and appears pink in basic solutions. A red litmus paper will turn blue in alkaline solutions while a blue litmus paper will turn red in acidic solutions.
Which products are the same in both the copper carbonate and the calcium carbonate if they react with hydrochloric acid in different reactions (shown above
Explanation:
the carbonate and the hydrochloric acid are the same in both reactions as products
Acetic acid only partially ionizes in water. A solution contains a large quantity of acetic acid dissolved in water. How can this acid solution best be described?
Answer:
The acid solution is a concentrated solution.
Explanation:
Acetic acid is a weak acid, because it ionizes partially in water as shown below:
CH3COOH + H2O —> H3O+ + CH3COO-
A solution containing a larger quantity of acetic acid is termed concentrated solution.
This is so because a concentrated solution is a solution that contains more of the solute than the solvent.
A solute is the substance which dissolves in the solvent.
A solvent is the substance which dissolves a solute.
In this case, acetic acid is the solute and water is the solvent.
Solution is simply the combination of solute and solvent
Solution => Solute + Solvent
More solute + Less solvent => Concentrated solution
Therefore, a solution containing a higher quantity of acetic acid ( i.e the solute) in water (i.e the solvent) is called a concentrated solution.
The _____ of an element is the total number of protons and neutrons in the ___ of the atom
Answer:
Mass number
Nucleus
Explanation:
The combined number of protons and neutrons is the mass number in atomic notation.
The atomic number is just the number of protons alone.
The nucleus holds both neutrons and protons.
Electrons circle around the nucleus.
Answer: atomic mass I did it
Explanation:
What is the correct way to represent the ionic compound sodium fluoride?
Answer: I don't know how to add a picture, so I might not explain this well.
Explanation: You put Na in the first box. Then you put F in the center of the second box because it gained one electron from Na. Then in the third box you put Na [+] because it lost one electron so it's now an cation(has a positive charge) because it lost a valence electron. In the last box you would put F [-] because it gained one electron so it's now an anion( has a negative charge) because it gained a valence electron. F now has 8 valence electrons and Na has 8 as well therefore they're both balanced.
The final method of sodium fluoride is NaF. An ionic compound is formed with the aid of the complete transfer of electrons from a steel to a nonmetal and the ensuing ions have achieved an octet.
what is the ionic compound for sodium fluoride?The chemical formula of sodium fluoride is NaF and its molar mass is 41.99 g/mol. it's miles an easy ionic compound, made from the sodium (Na+) cation and fluoride (F-) anion. The strong salt exists as cubic crystals just like the crystal structure of sodium chloride (NaCl).
what is sodium fluoride?Sodium fluoride is synthetic via the response of hydrofluoric acid with sodium carbonate or sodium hydroxide with the formula NaF. The most inexpensive chemical to be had for fluoridation is sodium fluorosilicate, formerly referred to as sodium silicofluoride.
Learn more about sodium fluoride here: https://brainly.com/question/15684463
#SPJ2
The intake stroke of a positive displacement compressor is most similar to that of a
A. thermostatic expansion valve.
B. auxillary electric water pump.
C. one-stroke variable displacement compressor.
D. two-stroke cylinder engine.
Answer:
D. two-stroke cylinder engine.
Explanation:
Two-stroke cylinder engine: In chemistry, the term "two-stroke cylinder engine" is described as one of the types of "internal combustion engine" that tends to complete a single "power cycle" possessing two different strokes of the "piston" during a particular "crankshaft revolution".
It generally consists of two different strokes that are being often known as power or exhaust and suction stroke.
In the question above, the given statement signifies the "two-stroke cylinder engine".
How does altitude affect climate patterns in a region? [Hint: relationship of altitude and temperature]
Answer:
Higher in the atmosphere temperature changes
Explanation: The tops of tall mountain might have ice or snow because it’s cooler in higher parts of the atmosphere.
Answer:
put the answers plz
Explanation:
The freezing point of pure chloroform is -63.5°C, and its freezing point depression constant is 4.07°C•kg/mol. If the freezing point of a solution of benzoic acid in chloroform is -70.55°C, what is the molality of this solution? 0.58 m 1.7 m 16 m 17 m
Answer: The molality of this solution is 1.7 m
Explanation:
Depression in freezing point:
[tex]T_f^0-T^f=i\times k_f\times m[/tex]
where,
[tex]T_f[/tex] = freezing point of solution = [tex]-70.55^0C[/tex]
[tex]T_f^0[/tex] = freezing point of pure chloroform = [tex]-63.5^0C[/tex]
[tex]k_f[/tex] = freezing point constant of benzene = [tex]4.07^0Ckg/mol[/tex]
m = molality
i = Van't Hoff factor = 1 (for non-electrolyte)
[tex]-63.5-(-70.55)^0C=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]7.05=1\times 4.07^0Ckg/mol\times m[/tex]
[tex]m=1.7[/tex]
Thus the molality of this solution is 1.7 m
How science classified?
any additional answer please thanks
Answer:
Scientific Classification. Classification, or taxonomy, is a system of categorizing living things. There are seven divisions in the system: (1) Kingdom; (2) Phylum or Division; (3) Class; (4) Order; (5) Family; (6) Genus; (7) Species. ... Species are identified by two names (binomial nomenclature)
Explanation:
what is a conjugate acid
THE conjugate acid, within the acid–base theory, is a chemical compound formed by the reception of a proton by a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a hydrogen ION.
:3. Give the names of salts tormed when: (a) Sodium metal replaces hydrogen ions of nitric acid. (b) Calcium metal partially replaces hydrogen ion of carbonic acid. (c) Ammonium ion replaces the hydrogen ions of hydrochloric acid. (d) Potassium metal partially replaces the hydrogen on of sulphuric acid.
Answer:
A. Sodium trioxonitrate (V) or sodium nitrat, NaNO3.
B. Calcium hydrogen carbonate, CaHCO3.
C. Ammonium chloride, NH4Cl.
D. Potassium hydrogen sulphate, KHSO4.
Explanation:
A. Sodium metal replaces hydrogen ions of nitric acid.
The equation for the reaction is given below:
2Na + 2HNO3 —> 2NaNO3 + H2
The salt formed is NaNO3 with the name sodium trioxonitrate (V) or sodium nitrate.
B. Calcium metal partially replaces hydrogen ion of carbonic acid.
The equation for the reaction is given below:
2Ca + 2H2CO3 —> 2CaHCO3 + H2
The salt formed is CaHCO3 with the calcium hydrogen carbonate
C. Ammonium ion replaces the hydrogen ions of hydrochloric acid.
The equation for the reaction is given below:
NH3 + HCl —> NH4Cl
The salt formed is NH4Cl with the name ammonium chloride.
D. Potassium metal partially replaces the hydrogen on of sulphuric acid.
The equation for the reaction is given below:
2K + 2H2SO4 —> 2KHSO4 + H2
The salt formed is KHSO4 with the name potassium hydrogen sulphate.
Indicators change color when an acid and a base are mixed together. The change in color most likely indicates that a chemical change has occured. a physical change has occured. a new acid has been produced. a new base has been produced.
Answer:
a chemical change
Explanation:
a physical change is mostly identified even without indicators i.e candle wax about forming a new acid or base I guess we have to include a ph scale to ascertain since the salt can be acidic but not necessarily an acid
Answer: The answer is A, a chemical change has occurred
Explanation:
I’m just a jenious
Why does fumaric acid have a higher boiling point than maleic acid, even though they both can form hydrogen bonds?
Answer:.
Explanation:
WHAT IS THE UNBALCNED EQUATION OF Methane burns in oxygen to produce carbon dioxide and water
Answer:
[tex]\boxed{CH_{4}+O_2 --> CO_2 + H_2O}[/tex]
Explanation:
Part 1: Naming compound formulas given the namesStep 1. Methane's formula is [tex]CH_4[/tex].
Step 2: Oxygen is a diatomic molecule (it exists bonded to itself for stability purposes), so by itself in chemical equations, it is written as [tex]O_2[/tex].
Step 3: Carbon dioxide is the molecular compound of one atom of carbon and two atoms of oxygen → [tex]CO_2[/tex].
Step 4: Water is the common name of the compound of two hydrogen atoms and one oxygen atom → [tex]H_2O[/tex].
Part 2: Writing the skeleton equationStep 1: Use the determined formulas for the reactants and plug them into the equation. We are told that methane burns in oxygen -- hinting at a combustion reaction. Therefore, we may infer that these are the reactants that yield the products.
Skeleton equations are written with the reactant(s) on the left -- if there are several, they are separated by an addition symbol (+).
With this information, we may begin our equation: [tex]CH_4 + O_2[/tex], where [tex]CH_4[/tex] is methane and [tex]O_2[/tex] is the diatomic molecule of oxygen.
Step 2: Use the determined formulas for the products and plug them into the equation. We are told that the methane burns in oxygen to produce carbon dioxide and water. Hence, we can separate these two as we did with the reactants.
Now, our products side of the reaction will look like this: [tex]--> CO_2 + H_2O[/tex], where [tex]CO_2[/tex] is carbon dioxide and [tex]H_2O[/tex] is water.
Step 3: Write the final equation. All you must do after determining both sides of the equation is simply push them together. Place the reactant side of the equation on the left and the product side of the equation on the right.
This gives us our final equation, [tex]\boxed{CH_4 + O_2 --> CO_2 + H_2O}[/tex].
Because the problem asks for the unbalanced equation, we do not need to take any further steps of balancing the equation.
A substance contains 23.0 g sodium, 27.0 g aluminum, and 114 g fluorine. How many grams of sodium are there in a 102-g sample of the substance? Select one: a. 4.43 g b. 23.0 g c. 14.3 g d. 102 g e. None of these
Answer:
E. None of the above
Explanation:
Si el elemento "X" tiene 8 protones y el elemento "Y" tiene 11 protones, al reaccionar ¿Qué tipo de enlace pueden formar? Seleccione una: a. Metálico. b. Covalente puro. c. Covalente polar. d. Iónico.
Answer:
D; Iónico
Explanation:
El elemento con 8 protones es oxígeno, mientras que el elemento con 11 protones es sodio.
El sodio es un metal alcalinotérreo, mientras que el oxígeno no es un metal.
En general, cuando tenemos un elemento metálico como el sodio, que se une con uno no metálico como el oxígeno, el tipo de enlace formado como resultado de la transferencia completa de electrones desde la capa de valencia del sodio a la capa de valencia del oxígeno para completar su propia configuración de octeto se denomina enlace electrovalente o, más generalmente, enlace iónico
4. How much force, in g cm / s2 , is exerted by a golf ball described in problem 2 striking a tree while accelerating at 20 cm / s2 ? Show how you can solve this problem without knowing that F = m a. Explain your solution.
Answer:
Explanation:ifk
A 36.0−g sample of an unknown metal at 99°C was placed in a constant-pressure calorimeter containing 70.0 g of water at 24.0°C. The final temperature of the system was found to be 28.4°C. Calculate the specific heat of the metal. (The heat capacity of the calorimeter is 12.4 J/°C.)
Answer: 0.52849 j /g °C
Explanation:
Given the following :
Mass of metal = 36g
Δ Temperature of metal = (28.4 - 99)°C = - 70.6°C
Mass of water = 70g
Δ in temperature of water = (28.4 - 24.0) = 4.4°C
Heat lost by metal = (heat gained by water + heat gained by calorimeter)
Quantity of heat(q) = mcΔT
Where; m = mass of object ; c = specific heat capacity of object
Heat lost by metal:
- (36 × c × - 70.6) = 2541.6c - - - - (1)
Heta gained by water and calorimeter :
(70 × 4.184 × 4.4) + (12.4 × 4.4) = 1288.672 + 54.56 = 1343.232 - - - - (2)
Equating (1) and (2)
2541.6c = 1343.232
c = 1343.232 / 2541.6
c = 0.52849 j /g °C