Answer:
See detailed explanation.
Explanation:
Hello.
In this case, since the electron configuration of potassium whose atomic number is 19 turns out:
[tex]K^{19}: 1s^2,2s^2,2p^6,3s^2,3p^6,4s^1[/tex]
We can see that the last level is 4 which has one electron, meaning that potassium has one valence electron. Moreover, since bromine's atomic number is 35, its electron configuration is:
[tex]Br^{35}: 1s^2,2s^2,2p^6,3s^2,3p^6,4s^2,3d^{10},4p^5[/tex]
We can see that the last level is also 4 and it has 2+5 = 7 valence electrons. In such a way, we infer that the valence electrons are computed by the electrons at the outer or last energy level of an element.
Regards.
Answer:
7
Explanation:
To make a ball move faster, you need to increase
The force applied to the ball
The size of the ball
O The mass of the ball
The friction under the ball
Answer:
The force applied to the ball.
Explanation:
Hope this helps!! Good luck!!
Which of the following can be broken down by chemical processes but not physical processes?
elements
compounds
all of these
mixtures
Answer:
Elements and compounds
Explanation:
Elements and compounds, mixtures are not chemically bonded and can be physically seperated
What is the Theoretical yeild of CaCO3 from 2 g of CaCl2 and 2.5 g of K2CO3
Answer:
Theoretical yield of CaCO₃ is 2.002 g.
Explanation:
Given data:
Mass of K₂CO₃ = 2.5 g
Mass of CaCl₂ = 2 g
Theoretical yield of CaCO₃ = ?
Solution:
Chemical equation:
K₂CO₃ + CaCl₂ → CaCO₃ + 2KCl
Number of moles of K₂CO₃:
Number of moles = mass/molar mass
Number of moles = 2.5 g/ 138.205 g/mol
Number of moles = 0.02 mol
Number of moles of CaCl₂:
Number of moles = mass/molar mass
Number of moles = 2 g/ 110.98 g/mol
Number of moles = 0.02 mol
Now we will compare the moles of CaCO₃ with K₂CO₃ and CaCl₂.
CaCl₂ : CaCO₃
1 : 1
0.02 : 0.02
K₂CO₃ : CaCO₃
1 : 1
0.02 : 0.02
Theoretical yield of CaCO₃:
Mass = number of moles × molar mass
Mass = 0.02 mol × 100.1 g/mol
Mass = 2.002 g
Theoretical yield of CaCO₃ is 2.002 g.
The storage method used for radioactive wastes generated from fission nuclear reactors must be designed to last for how long?
months
years
centuries
weeks
Answer: c
Explanation:
Answer: C - Centuries
Explanation:
What atomic symbol completes this reaction?
238 234.
U →
Th + ?
90
92
Answer:
Correct option is ₂⁴He
Explanation:
Uranium-238 undergo alpha decay and produce Th-234 and alpha particle.
₉₂U²³⁸ → ₉₀Th²³⁴ + ₂He⁴ + energy
Alpha radiations are emitted as a result of radioactive decay. The atom emit the alpha particles consist of two proton and two neutrons. It is also called helium nuclei. When atom undergoes the alpha emission the parent atom converted into the atom having mass number less than 4 and atomic number less than 2 as compared to parent atom.
Properties of alpha radiation:
Alpha radiations can travel in a short distance.
These radiations can not penetrate into the skin or clothes.
These radiations can be harmful for the human if these are inhaled.
These radiations can be stopped by a piece of paper.
how many seconds is in 1 year
Explanation:
hope it helps :)
In a saturated solution that is in contact with solid Mg(OH)2, the concentration of Mg2 is 1.31 X 10-4M. What is the solubility product for Mg(OH)2
Answer:
Ksp = 8.99x10⁻¹²
Explanation:
The solubility of Mg(OH)₂ is described with the reaction:
Mg(OH)₂(s) → Mg²⁺(aq) + 2OH⁻(aq)
The solubility product, Ksp, is:
Ksp = [Mg²⁺] [OH⁻]²
As you can see from the reaction, when 1 mole of Mg²⁺ is produced, 2 moles of OH⁻ are produced too, if [Mg²⁺] is 1.31x10⁻⁴M, [OH⁻] = 2.62x10⁻⁴M
Replacing:
Ksp = [Mg²⁺] [OH⁻]²
Ksp = [1.31x10⁻⁴M] [2.62x10⁻⁴M]²
Ksp = 8.99x10⁻¹²The solubility product of the [tex]\rm Mg(OH)_2[/tex] has been [tex]\rm 8.99\;\times\;10^{-12}[/tex].
The balanced equation for the dissociation of Magnesium hydroxide has been:
[tex]\rm Mg(OH)_2\;\rightarrow\;Mg^2^+\;+\;2\;OH^-[/tex]
From the balanced chemical equation, dissociation of 1 mole magnesium hydroxide has been resulted in the 1 mole magnesium and 2 mole hydroxide ions.
Since, given magnesium concentration, [tex]\rm Mg^2^+=1.31\;\times\;10^-^4\;M[/tex]
The concentration of hydroxide ion, [tex]\rm OH^-[/tex] will be:
[tex]\rm 1\;M\;Mg^2^+=2\;M\;OH^-\\1.31\;\times\;10^-^4\;M=1.31\;\times\;10^-^4\;\times\;2\;M\;OH^-\\1.31\;\times\;10^-^4\;M=2.62\;\times\;2\;M\;OH^-\\[/tex]
The solubility product (ksp) of the reaction has been given as:
[tex]ksp=\rm [Mg^2^+]\;[OH^-]^2[/tex]
Substituting the values for ksp:
[tex]ksp\;=\rm [1.31\;\times\;10^-^4]\;[2.62\;\times\;10^-^4]^2\\\textit ksp=8.99\;\times\;10^-^1^2[/tex]
The solubility product of the reaction has been [tex]\rm 8.99\;\times\;10^{-12}[/tex].
For more information about solubility product, refer to the link:
https://brainly.com/question/1163248
The reaction between ethylene and hydrogen bromide to form ethyl bromide is carried out in a continuous reactor. The product stream is analyzed and found to contain 56.7 mol% C2H5Br and 10.3 mol% HBr. The feed to the reactor conains only ethylene and hydrogen bromide. Calculate the fractional conversion of the limiting reactant and the percentage by which the other reactant is in excess. If the molar flow rate of the feed stream is 265 mol/s, what is the extent of reaction
Answer:
Extent of reaction = 95.9 mol.
Fractional conversion of the limiting reactant = 0.846.
Percentage by which the other reactant is in excess = 25.2 %.
Explanation:
Hello.
In this case, for the undergoing chemical reaction:
[tex]CH_2=CH_2+HBr\rightarrow CH_3-CH_2Br[/tex]
We can write the mole balance per species also including the extent of the reaction:
[tex]CH_2=CH_2:A\\\\HBr: B\\\\CH_3-CH_2-Br:C[/tex]
[tex]x_AP=z_AF-\epsilon \\\\x_BP=z_BF-\epsilon \\\\x_CP=\epsilon[/tex]
Considering that P is the flow of the outlet product. In such a way, writing the data we know, we can write:
[tex]0.33P=z_A*265-\epsilon \\\\0.103P=z_B*265-\epsilon \\\\0.567P=\epsilon[/tex]
Whereas we can replace the C2H5Br mole balance in the others mole balances:
[tex]0.33P=z_A*265-0.567P \\\\0.103P=z_B*265-0.567P\\\\\\z_A*265-0.897P=0\\\\z_B*265-0.67P=0[/tex]
By knowing that [tex]z_B=1-z_A[/tex], we can write:
[tex]z_A*265-0.897P=0\\\\(1-z_A)*265-0.67P=0\\\\\\z_A*265-0.897P=0\\\\-z_A*265-0.67P=-265[/tex]
Thus, solving for P and [tex]z_A[/tex], we obtain:
[tex]z_A=0.572\\\\P=169.11mol[/tex]
It means that the extent of the reaction is:
[tex]\epsilon=0.567P=0.567*169.11mol\\\\\epsilon=95.9mol[/tex]
For the limiting reactant, due to the 1:1 mole ratio between the reactants, it is the one having the smallest flow rate:
[tex]F_A=0.572*265mol=151.58mol\\\\F_B=265mol-151.58mol=113.42mol[/tex]
It means that the limiting reactant is B which is HBr, whose fractional conversion is:
[tex]X_B=1-\frac{0.103*169.11}{113.42mol}\\ \\X_B=0.846[/tex]
Finally, the percentage by which the other reactant is in excess, corresponds to:
[tex]\% excess =(1-\frac{113.42mol}{151.58mol})*100\%\\ \\\%excess=25.2\%[/tex]
Regards.
0
Chem
Equations
Balance and Classify each of the following equations into:
Combination reaction, Decomposition Reaction, Single
Replacement reaction, Combustion reaction Double
Replacement reaction
A)
KBr(aq) + Cl2(g) → _ KCl(aq) + Br2(1)
B)
CaBr2(aq)
+ H2SO4(aq) - CaSO4(s) +_HBr(g)
N2(g) + H2(g) + NH3(g)
Grading: Each Equation Balanced --2 points, Classification --
1 point each
Ontime submission ---1 point
DUE: Oct 9, 2020 at 11:00 AM
Answer :
(A) The balanced chemical reaction will be:
[tex]2KBr(aq)+Cl_2(g)\rightarrow 2KCl(aq)+Br_2(l)[/tex]
This reaction is a single replacement reaction.
(B) The balanced chemical reaction will be:
This reaction is a double displacement reaction.
(C) The balanced chemical reaction will be:
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
This reaction is a combination reaction.
Explanation :
Balanced chemical reaction : It is defined as the reaction in which the number of atoms of an element present on reactant side must be equal to the product side.
Part (A):
The balanced chemical reaction will be:
[tex]2KBr(aq)+Cl_2(g)\rightarrow 2KCl(aq)+Br_2(l)[/tex]
This reaction is a single replacement reaction in which the most reactive element displaces the least reactive element from its solution.
Part (B):
The balanced chemical reaction will be:
[tex]CaBr_2(aq) +H_2SO_4(aq)\rightarrow CaSO_4(s)+2HBr(g)[/tex]
This reaction is a double displacement reaction in which a positive cation and a negative anion of two reactants exchange their places to form two new products.
Part (C):
The balanced chemical reaction will be:
[tex]N_2(g)+3H_2(g)\rightarrow 2NH_3(g)[/tex]
This reaction is a combination reaction in which the two atoms combine to form a larger molecule.
Question 1 (5 points)
Calculate the frequency of a photon that exhibits a wavelength of 451 nm.
Equation: E = hu
h = 6.63 x 10-34]'s
Answer:
e
Explanation:
an unknown solution gives a yellow-green flame test
Answer:
Barium
Explanation:
6th grade help me plzzzzzz
Answer:
It's protons and neutronsExplanation:
Hope this helpsKatiana wanted to figure out what type of liquid worked best for growing beans. She watered one with coca-cola, one with lemonade, and one with just water. After one week, she measured how high they had grown. Independent Variable (What I, the scientist test or change) *
Helppppp pleaseee fasst What branch of mathematics' principles were the Islamic artists apparently using?
a. Calculus
C. Trigonometry
b. Quasicrystalline geometry
d. Algebra
Please select the best answer from the choices provided
Answer:
its b.
Explanation:
Which characteristic describes bases?
taste sour
feel slippery
react with metals
are used to remove rust
Answer:
feel slippery
Explanation:
Bases are certain metallic oxides, metallic hydroxides and aqueous ammonia. They typically have the following characteristics;
The aqueous solution of many of them have a bitter taste. The aqueous solutions of bases have soapy or slippery feel and the strong bases are very caustic to the skin. Their aqueous solutions have a pH greater than 7. Bases have the ability to change the color of indicators. They are conduct electricity and are said to be electrolytes.From the choices given, the fitting answer is that bases have a slippery feel.
Answer:
B) Feel slippery
Explanation:
Just did the assignment
What do you notice about the pattern of volcanoes?
Answer:
What patterns do volcanoes form?
Volcanoes occur at convergent plate boundaries were subducting oceanic crust is melted. This magma rises through the crust to form volcanoes and volcanic island arcs. Volcanoes occur at divergent plate boundaries where upwelling magma pushes between plates (rift zones) as the plates move apart.
For the reactions below, describe the reactor system and conditions you suggest to maximize the selectivity to make the desired species, D, which is a very small molecule. For full credit, support your suggestions with clear calculations, explanations and sketches where appropriate. Rates are in mol/L.s and concentrations are in mol/L. Reaction 1: A+B D -r1A= 10 exp[-8000 K/T]CACB Reaction 2: B+D U -r2B= 109 exp[-10,000 K/T]CBCD BELOW – make sure to note highlighted question number for answers on Exam Paper. 4. Describe the reactor system and conditions: ___ Answer written on Exam paper AND in BB
Answer:
hello your question lacks the required reaction pairs below are the missing pairs
Reaction system 1 :
A + B ⇒ D [tex]-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}[/tex]
A + B ⇒ U [tex]-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}[/tex]
Reaction system 2
A + B ⇒ D [tex]-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}[/tex]
B + D ⇒ U [tex]-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}[/tex]
Answer : reaction 1 : description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1
condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2
reaction 2 :
description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1
condition to maximize selectivity:
to increase selectivity the concentration of D should be minimal
Explanation:
Reaction system 1 :
A + B ⇒ D [tex]-r_{1A} = 10exp[-8000K/T]C_{A}C_{B}[/tex]
A + B ⇒ U [tex]-r_{2a} = 100exp(-1000K/T)C_{A} ^\frac{1}{2}C_{B} ^\frac{3}{2}[/tex]
the selectivity of D is represented using the relationship below
[tex]S_{DU} = \frac{-r1A}{-r2A}[/tex]
hence SDu = 1/10 * [tex]\frac{exp(-800K/T)}{exp(-1000K/T)} * C_{A} ^{0.5} C_{B} ^{-0.5}[/tex]
description of the reactor system : The desired reaction which is the first reaction possess a higher activation energy and higher temperature is required to kickstart reaction 1
condition to maximize selectivity : To maximize selectivity the concentration of reaction 1 should be higher than that of reaction 2
Reaction system 2
A + B ⇒ D [tex]-r_{1A} = 10exp( -1000K/T)C_{A}C_{B}[/tex]
B + D ⇒ U [tex]-r_{2B} = 10^9exp(-10000 K/T) C_{B}C_{D}[/tex]
selectivity of D
[tex]S_{DU} = \frac{-r1A}{-r2A}[/tex]
hence Sdu = [tex]1/10^7 * \frac{exp(-1000K/T)}{exp(-10000K/T)} *\frac{C_{A} }{C_{D} }[/tex]
description of reactor system : The desired reaction i.e. reaction 1 has a lower activation energy and lower temperatures is required to kickstart reaction 1
condition to maximize selectivity:
to increase selectivity the concentration of D should be minimal
a jaguar can run up to 50 miles per hour, how many feet can he run per second? give your answer in scientific notation to one and three significant figures.
Answer:
50x10^0
Explanation:
True or False – When earthquakes occur, they form huge gaps in the earth’s surface.
Answer:
i think the answer is true pls mark branliest
Explanation:
Answer:
its true! earth quakes do form huge gaps in the earth surface
Explanation:
What element has an atomic mass 4?
Answer:
Helium has atomic mass 4.002602.
So the answer to yr question is helium.
why do we study properties of matter
Answer:
The properties of matter include any traits that can be measured, such as an object's density, color, mass, volume, length, malleability, melting point, hardness, odor, temperature, and more. We need to study all these traits since every single object around us, including us, is made of matter. Without matter we wouldn't exist; it would be infinite darkness everywhere.
what would happen to global temperatures of solar energy was unbalanced
Answer:
mostly skin diseases
Explanation:
because of greenhouse effects
I’m confused on this
Answer:
B
Explanation:
The scientist had a wrong hypothesis?
Answer:
it would be C.
Explanation:
becuase the scientist would know what to to next time for his next experiment. even if it went wrong, he can try to get it right again.
Where does the energy within the greenhouse effect originate?
from convection within the atmosphere
from the circular movement of hot and cold air
from solar radiation entering the atmosphere
from the conduction of heat from the ground to the air
Answer:
from solar radiation entering the atmosphere
Explanation:
The energy within the greenhouse effect is originated from solar radiation entering the atmosphere, hence option C is correct.
What is solar radiation?Solar radiation is a broad word for the electromagnetic radiation that the sun emits. It is also sometimes referred to as the solar resource or just sunshine.
A variety of devices can be used to collect solar radiation and transform it into useful forms of energy, such as heat and electricity.
Heat is reflected into the atmosphere from solar energy that has been absorbed in the earth's surface.
Greenhouse gases absorb a large portion of the heat as it travels through the atmosphere and is radiated back into space.
Therefore, the greenhouse effect is powered by solar radiation that reaches the atmosphere.
Learn more about solar radiation, here:
https://brainly.com/question/23338147
#SPJ5
Please help!!!!!!!!!!!
Answer:
They both have two valence electrons
Answer:
I am guessing because they are both metals
pls help me with this!!
Answer:
B. 65
Explanation:
arrange your numbers as:
63,64,66,69
add 64 and 66 together to get 130 then divide by 2
-or just think about what number is between 64 and 66
58:27
1
Dominic made the table below to organize his notes about mixtures
Properties of Mixtures
has no set composition
must have more than one state of matter
must have more than one substance
What mistake did Dominic make?
The title should read "Properties of Solutions" because some mixtures do not have all of the properties listed
O There is a definite recipe to make each mixture, so the composition of a mixture is set.
Although it is possible to have more than one state, it is also possible to have only one state.
O A single substance can be used to make a mixture if the substance is composed of more than one element
Sao and Fit
Answer:
Although it is possible to have more than one state, it is also possible to have only one state.
Explanation:
The mistake Dominic made was stating that "although it is possible to have more than one state, it is also possible to have only one state."
Mixtures are impure substances with the following properties:
They have an indefinite composition
Their constituents retains their identities.
Constituents react differently to changed conditions.
They can easily be separated into constituents by physical methods.
There are two types of mixtures based on the number of phases coexisting:
Homogeneous mixtures have their constituents existing in just one phase.
Heterogeneous mixtures exists in at least two different phases.
Explanation:
The periodic table says that the average mass of copper is 63.55 but there is no such thing as copper-63.55. Why? (please use copper-63 and copper-64 in your answer)
Answer:
69%for the isotope that weighs 62.93 u and
31
%
for the isotope that weighs 64.93 u.
You can approach this problem by using a single equation; let's say the first isotope contributes to the relative atomic mass by a fraction
x
(
x
<
1
). SInce there are only 2 isotopes to consider, the fraction the other isotope contributes with will automatically be
1
−
x
.
Let's set up the equation
x
⋅
62.93
u
+
(
1
−
x
)
⋅
64.93
u
=
63.55
u
Solving this for
x
will produce
64.93
u
−
63.55
u
=
2
x
→
x
=
1.38
2
=
0.69
Multiplying these fractions (0.69 and 1 - 0.69 = 0.31) by 100% percent to get the results as a percentage will give
69
%
for the isotpe that weighs 62.93u and
31
%
for the one that weighs 64.93u.
Answer link
Which statement best describes how an ionic bond forms?
6.An acid-base indicator is usually a weak acid with a characteristic color in the protonated and deprotonated forms. Because bromocresol green is an acid, it is convenient to represent its rather complex formula as HBCG. HBCG ionizes in water according to the following equation:HBCG + H2O = BCG- + H3O+ (yellow)(blue)The Ka (the equilibrium constant for the acid) expression is: Ka=[BCG−][H3O+][HBCG]When [BCG-] = [HBCG], then Ka = [H3O+]. If you know the pH of the solution, then the [H3O+] and Ka can be determined. What would be the color of the solution if there were equal concentrations of HBCG and BCG-?Solution Color: _______________What is the pH at the first appearance of this color?Solution pH: __________What is an estimate for the Ka for bromocresol green? Show your work to get full credit
Answer:
At equal concentration of HBCG and BCG^-, the colour is green. This colour first appears at pH = 3.8
Explanation:
HBCG is an indicator that is prepared by dissolving the solid in ethanol.
Since
Ka=[BCG−][H3O+][HBCG]When [BCG-] = [HBCG], then Ka = [H3O+].
If pH = 3.8
Ka= [H3O+] = -antilog pH = -antilog (3.8)
Ka= 1.58 ×10^-4
