Answer:
Ba(OH)₂ + 2 HBr ⇒ BaBr₂ + 2 H₂O
Explanation:
We have the products of a reaction and we have to predict the reactants. Since the products are binary salt and water, this must be a neutralization reaction. In neutralizations, acids react with bases. The acid that gives place to Br⁻ is HBr, while the base the gives place to Ba²⁺ is Ba(OH)₂. The balanced chemical equation is:
Ba(OH)₂ + 2 HBr ⇒ BaBr₂ + 2 H₂O
The energy levels of hydrogenlike one-electron ions of atomic number Z differ from those of hydrogen by a factor of Z^2. Predict the wavelength of the 2s--->1s transition in He+.
Answer:
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Explanation:
For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:
[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]
where:
emitted radiation of the wavenumber [tex]\bar v[/tex] = ???
atomic no of helium Z = 2
Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]
the initial energy of the principal quantum [tex]n_1[/tex] = 2
the initial energy of the principal quantum [tex]n_1[/tex] = 2
Now, the emitted radiation of the wavenumber can be computed as:
[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]
[tex]\bar v = 3.291 \times 10^ 7/m[/tex]
Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber [tex]\bar v[/tex], which is:
[tex]\bar v = \dfrac{1}{\lambda}[/tex]
[tex]\lambda = \dfrac{1}{\bar v}[/tex]
[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]
[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]
[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]
Enter a balanced equation for the reaction between solid nickel(II)(II) oxide and carbon monoxide gas that produces solid nickel and carbon dioxide gas. Express your answer as a chemical equation. Identify all of the phases in your answer.
Answer: A balanced equation for the given reaction is [tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex].
Explanation:
The reaction equation will be as follows.
[tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex]
Number of atoms on the reactant side is as follows.
O = 2C = 1Number of atoms on the product side is as follows.
Ni = 1O = 2C = 1Since number of atoms on both the reactant and product sides are equal. Hence, the reaction equation is balanced.
Thus, we can conclude that a balanced equation for the given reaction is [tex]NiO(s) + CO \rightarrow Ni(s) + CO_{2}(g)[/tex].
Consider the following chemical equilibrium: Now write an equation below that shows how to calculate from for this reaction at an absolute temperature . You can assume is comfortably above room temperature. If you include any common physical constants in your equation be sure you use their standard symbols, found in the ALEKS Calculator.
Answer:
Kp=Kc *(RT)+-3
Explanation:
The relation between Kp and Kc is given below:
Where,
Kp is the pressure equilibrium constant
Kc is the molar equilibrium constant
R is gas constant , R = 0.082057 L atm.mol⁻¹K⁻¹
T is the temperature in Kelvins
Δn = (No. of moles of gaseous products)-(No. of moles of gaseous reactants)
For the first equilibrium reaction:
Δn = (0)-(2+1) = -3
Thus, Kp is:
Kp=Kc *(RT)+-3
How many g of Al are required to produce 2.8 mol of Al2O3
Answer:
290 g Al₂O₃
General Formulas and Concepts:
Atomic Structure
Reading a Periodic TableMolesStoichiometry
Using Dimensional AnalysisExplanation:
Step 1: Define
[Given] 2.8 mol Al₂O₃
[Solve] g Al₂O₃
Step 2: Identify Conversions
[PT] Molar Mass of Al: 26.98 g/mol
[PT] Molar Mass of O: 16.00 g/mol
Molar Mass of Al₂O₃: 2(26.98) + 3(16.00) = 101.96 g/mol
Step 3: Convert
[DA] Set up: [tex]\displaystyle 2.8 \ mol \ Al_2O_3(\frac{101.96 \ g \ Al_2O_3}{1 \ mol \ Al_2O_3})[/tex][DA] Multiply [Cancel out units]: [tex]\displaystyle 285.488 \ g \ Al_2O_3[/tex]Step 4: Check
Follow sig fig rules and round. We are given 2 sig figs.
285.488 g Al₂O₃ ≈ 290 g Al₂O₃
Topic: AP Chemistry
Unit: Atomic Structure
Methanol has the formula CH3OH. What is the predominant intermolecular force between methanol molecules?
ANSWER:
dispersion forces
dipole forces
ionic bonds
hydrogen bonds
Answer:
hydrogen bonds
Explanation:
similarly CH3OH also has a OH group and H hydrogen thus it will also form h-bonding.
What is the
energy
2) The energy transition from n = 1 →n= 3 in hydrogen is 12.09 eV (1.6022 X 10J= 1 eV)-
of light emitted from n = 3 →n=1?
E e fiz
Answer:
energy is the ability to do work
Which of the following was NOT explained by Dalton's atomic theory?
ANSWER:
A. the Law of Multiple Proportions
B. the difference between elements and compounds
C.?the difference between isotopes of an element
D. the Law of Conservation of Mass
Answer:
i think 1. law of muliple proportion
Explanation:
please like
A soluble unknown has contaminated your sample. It absorbs the same wavelength as your analyte, Allura Red dye. How will this affect your results, and what type of error is introduced
Answer:
The explanation as per the given query is presented in the following paragraph.
Explanation:
The Allura Reds Pigment or coloring increases the absorption by absorbing at around a very similar wavelength as that of the analysis.Therefore, the approximated analysis concentration or its intensity seemed substantially higher than that of the authentic one. Some positive mistake is going to exist.Thus the above is the correct explanation.
The measured absorbance will be higher, thereby creating systematic error.
Absorbance can be defined as the value or quantity of light absorbed by a given sample.The presence of impurity with a similar absorption wavelength will increase the absorbance. Moreover, systematic error is a type of error that is repeated along with different processes of measurement.In conclusion, the measured absorbance will be higher, thereby creating systematic error.
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Which probing question lies within the scope of physics?
O A.
Are fish in the open ocean
attracted by underwater sounds?
O B.
Does increasing the saltiness of
ocean water affect the speed
of sound in the water?
O C.
What effect does the release of industrial wastewater have on
the acidity of oceans?
D. What is the effect of rising sea temperatures on
ocean currents?
Answer:
answer number C is the correct answer for this
In a classroom, students who are biochemistry majors are learning about the overall organization of biological membranes. However, one of the students finds a WRONG explanation about the fluid mosaic model from a website and bring it up in a discussion. Which of the following is a WRONG explanation?
a. An explanation of the two-dimensional solutions of oriented lipids and globular proteins.
b. The lipid bilayer is a solvent for integral membrane proteins.
c. All membrane proteins diffuse laterally and freely in the lipid matrix.
d. None of the answers is correct.
e. The lipid bilayer is a permeability barrier for integral membrane proteins.
Answer:
e. The lipid bilayer is a permeability barrier for integral membrane proteins.
Explanation:
Integral membrane proteins enter the lipid bilayer by translocon channel which gives nascent polypeptide segment a chance to partition itself into lipid bilayer hydrophobic core.
if salt and sand is mixed with distilled water, what will be the residue and what will be the filtrate?
Answer:
salt and sand
Explanation:it is what it is
Question 65 pts
(07.02 MC)
During a reaction, ΔH for reactants is −750 kJ/mol and ΔH for products is 920 kJ/mol. Which statement is correct about the reaction? (5 points)
Group of answer choices
It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.
It is endothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.
It is exothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed.
It is exothermic because the energy required to break bonds in the reactants is greater than the energy released when the products are formed.
Answer:
It is endothermic because the energy required to break bonds in the reactants is less than the energy released when the products are formed
Explanation:
A reaction may be endothermic or exothermic. In an endothermic reaction, energy is absorbed by the process while in an exothermic process energy is given out by the process.
Recall that the enthalpy change of a reaction = enthalpy of products - enthalpy of reactants
Hence, where the energy required to break bonds in the reactants is less than the energy released when the products are formed, the reaction is endothermic.
For an endothermic reaction, the enthalpy change of the reaction is positive.
In this case, enthalpy of reaction = 920 - (-750) = 1670 kJ/mol
A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to Group of answer choices sulfur, oxygen, or fluorine. oxygen or nitrogen. fluorine, oxygen, or nitrogen. nitrogen, fluorine, oxygen, or nitrogen. chlorine, fluorine, or iodine.
Answer: A molecule contains hydrogen bonding if it contains hydrogen covalently bonded to (fluorine, oxygen, or nitrogen)
Explanation:
A hydrogen bond is a strong dipole-dipole attraction which occurs between
--> the hydrogen atom attached to a strongly electronegative atom, and
--> another strongly electronegative atom with a lone pair of electrons.
When an electronegative atom such as fluorine, oxygen or Nitrogen is bonded to hydrogen, a dipole develops causing the hydrogen to be partially negative. The electrostatic attraction between the partially positive hydrogen atom in one molecule and the partially negative atom of the more electronegative element in another molecule gives rise to the strong dipole-dipole attraction called hydrogen bonding.
Hydrogen fluoride, water and ammonia contain the three most electronegative elements, fluorine, oxygen and nitrogen respectively, linked directly to hydrogen. In addition, lone pairs of electrons are present in the fluorine, oxygen and nitrogen atoms of the three hydrides, making hydrogen bonds to form easily between them. These compounds which exhibits hydrogen bonding always have higher melting and boiling points.
what does LPG stand for? mention one important source of LPG give sort answer
Answer:
liquefied petroleum gas
LPG is prepared by refining natural gas. it is made by refining crude oil or from extracted natural gas streams as they emerge from the ground.
define the following terms atom
if salt and sand is mixed with distilled water, what will be the residue? and, what will be the filtrate?
Answer:
Filtration is a technique used as a remedy to separate mixes
Explanation:
If you have a sodium, then you will explore that salt dissolves but the sand is still the same.
If the salt in the resin water solution scanners, the sand remains the residue and passes through the filter paper.
All you have to do now is pleasant the salty water so that the water can evaporate, leaving the salt behind.
Someone can you please please help me
Answer:
FalseExplanation:
Target organ toxins are chemicals that can cause adverse effects or disease states manifested in specific organs of the body. Toxins do not affect all organs in the body to the same extent due to their different cell structures.
Which of the following describes an organisms habitat?
A) where the organism lives
B) how the organism moves
C) what the organism eats
D) what eats the organism
Answer:
A) habitat
Explanation:
a habitat is essentially the organisms "home". also known as a "niche"
The radius of a platinum atom is 139 pm. How many platinum atoms would have to be laid side by side to span a distance of 1.39 mm?
Answer:
5x10⁶ atoms of platium have to be laid side by side
Explanation:
1 atom of platium has a radius of 139pm = 139x10⁻¹²m. The distance that occupies 1 atom of platinum is 2 times its ratio:
139x10⁻¹²m*2 = 2.78x10⁻¹⁰m
Assuming there is no distance between to atoms of platinum, just its ratio. The amount of atoms necessary to occupy 1.39mm = 1.39x10⁻³m is:
1.39x10⁻³m / 2.78x10⁻¹⁰m =
5x10⁶ atoms of platium have to be laid side by side6. Which compound contains no ionic character?
Answer:
The compound which doesn't contains ionic character is HC, H-atom and CL- atom shares 1 electron a to form covalent bond....
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Answer:
An unknown compound's 2,4-DNP product melting range is between 144-146'C. It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test. What would this compound be
Explanation:
From the given data it is clear that the unknown compound gives positive test with 2,4-DNP reagent.
That means it has a carbonyl group.Either aldehyde or ketone.
It does not give a silver mirror on the Tollens test and is slow to react to the chromic acid test.
That means aldehyde is absent.
So, the other carbonyl group that is ketone is present in the given unknown compound.
Which of the following is true for balancing equations?
A. There must be an equal number of atoms of each element on both sides of the equation.
B. The number of products should be equal to the number of reactants
C. The properties of products should be the same as the properties of the reactants
D. There must be an equal number of compounds on both sides of the equation
Answer:
A.
Explanation:
An equation with the equal amount and proportion of atoms of each element on both sides of the reaction is commonly referred to as a balanced chemical equation.
The law of conservation of matter asserts that no observable and empirical change in the amount of matter occurs within a conventional chemical process. As a result, each element in the product would have the same equal amount or numbers of atoms as the reactants.
For which of the following transitions would a hydrogen atom absorb a photon with the longest wavelength?
a. n = 1 to n = 2
b. n = 3 to n = 2
c. n = 5 to n = 6
d. n = 7 to n = 6
Answer:
Hence among the options a and c, option d is that the correct answer because it has rock bottom energy ( as n value increases, energy decreases as energy levels come closer).
Explanation:
The relation between energy and wavelength is:
[tex]\Lambda = hC/E[/tex]
From this equation, it's clear that wavelength and energy are inversely proportional to every other. The Lower the energy of a specific transition, the longest will the wavelength be of that specific transition.
Among the given options, options b and d are often ruled out, since those transitions produce to release of a photon because it is coming down from an excited state.
A sample of brass, which has a specific heat capacity of , is put into a calorimeter (see sketch at right) that contains of water. The temperature of the water starts off at . When the temperature of the water stops changing it's . The pressure remains constant at . Calculate the initial temperature of the brass sample. Be sure your answer is rounded to significant digits.
Answer:
The initial temperature of the brass sample is 90.1°C
Note: The question is incomplete. A similar but complete question is given below :
A 52.9g sample of brass, which has a specific heat capacity of 0.375·J·g−1°C−1, is put into a calorimeter (see sketch at right) that contains 100.0g of water. The temperature of the water starts off at 15.0°C. When the temperature of the water stops changing it's 18.4°C. The pressure remains constant at 1 atm. Calculate the initial temperature of the brass sample. Be sure your answer is rounded to 2 significant digits.
Explanation:
Assuming that the calorimeter is an isolated system and that no heat is lost from the calorimeter. The total heat in the system is the sum of the heat content of the brass and that of water
Total heat lost by the brass = heat gained by the water
The quantity of heat lost or gained, Q = mcΔT
Where m = mass of the substance, c = specific heat capacity of substance, ΔT = temperature change
Heat gained by water is positive while heat lost by brass is negative
mass of brass = 52.9 g, specific heat capacity of brass = 0.375·J·g−1°C−1, ΔT = (18.4 - t °C; where t is the initial temperature), mass of water = 100.0 g, specific heat capacity of water = 4.186 J/g°C, ΔT = = 18.4 - 15.0 = 3.4 °C
Heat lost by brass z= - [ 52.9 × 0.375 × (18.4 - t)] = -365.01 + 19.8375t
Heat gained by water = 100 × 4.186 × 3.4 = 1423.24
Equating heat lost by brass to heat gained by water
-365.01 + 19.8375t = 1423.24
19.8375t = 1423.24 + 365.01
19.8375t = 1788.25
t = 90.1° C
Therefore, the initial temperature of the brass sample is 90.1°C
important of organic chemistry in our daily life
Answer:
Human life has become very simple by using organic chemicals. The importance of organic chemicals in the daily life and industrial area can be explained as follows. (i) Food Vitamins, proteins, sugar, flour, fats etc. ... (ii) Agriculture is an important place for organic chemical for the growth of agricultural production.
What is the gravitational potential energy of a 1500-kg truck resting on top of a 550-m hill on earth?( earth’s gravitational pull is 9.8m/s2).
Answer:
E = 8085 kJ
Explanation:
Given that,
The mass of a truck, m = 1500 kg
Height, h = 550 m
We need to find the gravitational potential energy of the truck. It can be calculated as follows :
[tex]E=mgh[/tex]
Put all the values,
[tex]E=1500\times 9.8\times 550\\\\E=8085000\ J\\\\or\\\\E=8085\ kJ[/tex]
So, the gravitational potential energy is 8085 kJ.
A calorimeter has been filled with 75 mL of water. The density of water at 25 °C is
0.998 g/mL. How many grams of water do you have at 25°C?
Answer:
isn't it 0.998
Explanation:
cause 0.998 is in the same grams / mole. I don't get
A calorimeter has been filled with 75 mL of water. The number of grams of water is 74.85 grams.
What is a calorimeter?A calorimeter is an instrument that is used to measure calorimetry. It is used to measure the heat of chemical reactions and physical and chemical changes.
Mass is the quantity of matter in a physical body. Volume is the space occupied by a three-dimensional object. Mass is the quantity of matter in a physical body. The product of the compound's molar mass and the substance's moles are defined as mass.
Given, that the volume of the water is 75 mL
The temperature of the water is 25 °C
The density of water is 0.998 g/mL
To calculate the mass, the volume is multiplied by density.
Mass = volume x density
putting the values in the formula
75 x 0.998 = 74.85 grams
Thus, the grams of water that have at 25°C is 74.85 grams.
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Why do gases act more ideal at
lower pressures?
Answer:
Gases act more ideal at lower pressure beacuse the attractive forces between molecules will decrease or become less significant compared to the empty space between them.
Explanation:
Generally, a gas behaves more like an ideal gas at higher temperature and lower pressure as the potential energy due to intermolecular forces becomes less significant compared with the particles "kinetic energy" and the size of the molecules become less significant compared to the empty space between them.
Attractive forces between molecules, decrease the pressure of a reak gas, slowing the molecules and reducing collisions with the walls.The higher the value of a gas, the greater the attraction between molecules and the more easily the gas will compress.
HOPE IT HELPS MUCHanswered by: John Glenly Pillazo Mahusay
A sample of Br2(g) takes 12.0 min to effuse through a membrane. How long would it take the same number of moles of Ar(g) to effuse through the same membrane
Answer:
6 mins
Explanation:
The time taken for Ar to effuse can be obtained as follow:
Time for Br₂ (t₁) = 12 mins
Molar mass of Br₂ (M₁) = 2 × 80 = 160 g/mol
Molar mass of Ar (M₂) = 40 g/mol
Time for Ar (t₂) =?
t₂/t₁= √(M₂/M₁)
t₂ / 12 = √(40/160)
Cross multiply
t₂ = 12 × √(40/160)
t₂ = 12 × 0.5
t₂ = 6 mins
Therefore, it will take 6 mins for the same amount of Ar to effused out.
For each of the following changes at equilibrium, indicate whether the equilibrium shifts in the direction of products, reactants, or does not change: CaCO3(s)+heat⇌CaO(s)+CO2(g)
1) increasing the temperature
shifts equilibrium in the direction of the reactants
does not change
shifts equilibrium in the direction of the products
2) decreasing the volume of the container
shifts equilibrium in the direction of the reactants
shifts equilibrium in the direction of the products
does not change
3) adding a catalyst
shifts equilibrium in the direction of the reactants
shifts equilibrium in the direction of the products
does not change
4) adding more CaO(s)
does not change
shifts equilibrium in the direction of the reactants
shifts equilibrium in the direction of the products
Answer:
shifts equilibrium in the direction of the products
shifts equilibrium in the direction of the reactants
does not change
shifts equilibrium in the direction of the reactants
Explanation:
When a constraint such as a change in pressure, concentration or temperature is imposed on a reaction system in equilibrium, the equilibrium position will shift in such a way as to annul the constraint.
The reaction is endothermic as written. Hence, increase in temperature increases the rate of forward reaction thereby shifting the equilibrium position towards the products.
When the volume of a reaction is decreased, the equilibrium position shifts in the direction which produces the least total volume. In this case, decrease in volume shifts the equilibrium position towards the reactants.
A catalyst has no effect on the equilibrium position. However, a catalyst may cause equilibrium to be achieved faster or at a lower temperature.
When more CaO is added, the equilibrium position shifts towards the reactants side and more CaCO3 is produced.
