Answer:
red, yellow, blue are the 3 main primary colors
Why doesn't the outer electron on the potassium atom experience the full charge of the protons in the nucleus (+19)?
I believe the answer is C. There are 19 electrons shielding it from the nucleus
In a generic chemical reaction involving reactants A and B and products C and D, aA + bB → cC + dD, the standard enthalpy ΔH∘rxn of the reaction is given by
ΔH∘rxn = cΔH∘f(C) + dΔH∘f(D) − aΔH∘f(A) − bΔH∘f(B)
Notice that the stoichiometric coefficients, a, b, c, d, are an important part of this equation. This formula is often generalized as follows, where the first sum on the right-hand side of the equation is a sum over the products and the second sum is over the reactants:
ΔH∘rxn = ∑products nΔH∘f − ∑reactants mΔH∘f
where m and n represent the appropriate stoichiometric coefficients for each substance.
A. What is ΔH∘rxn for the following chemical reaction?
H2O(l) + CCl4(l) → COCl2(g) + 2HCl(g)
You can use the following table of standard heats of formation (ΔH∘f) to calculate the enthalpy of the given reaction.
Element/ Standard Heat of Element/ Standard Heat of
Compound Formation (kJ/mol) Compound Formation (kJ/mol)
H(g) 218 N(g) 473
H2(g) 0 O2(g) 0
CCl4(l) −139.5 O(g) 249
H2O(l) −285.8 HCl(g) −92.30kJ
C(g) 71 COCl2(g) −218.8kJ
C(s) 0 HNO3(aq) −206.6
B. Chemical energy is released or absorbed from reactions in various forms. The most easily measurable form of energy comes in the form of heat, or enthalpy. The enthalpy of a reaction can be calculated from the heats of formation of the substances involved in the reaction: ΔH∘rxn = Σ npΔH∘f(products) − Σ nrΔH∘f(reactants)where n represents the stoichiometric coefficients.
Calculate the standard enthalpy change for the reaction 2A + B ⇌ 2C + 2DUse the following data:
Substance ΔH∘f(kJ/mol)A -225B -377C 181D -523
C. Ethanol can be made from the fermentation of crops and has been used as a fuel additive to gasoline. Write a balanced equation for the combustion of ethanol.
Answer:
A. ΔH∘rxn = 21.9 KJ/mol
B. ΔH∘rxn = 103 KJ/mol
C. C2H5OH + 3O2 → 2CO2 + 3H2O
Explanation:
A.
The standard reaction equation is given as:
aA + bB → cC + dD
Its standard enthalpy is given as:
ΔH∘rxn = cΔH∘f(C) + dΔH∘f(D) − aΔH∘f(A) − bΔH∘f(B)
Reaction given to us is:
H2O(l) + CCl4(l) → COCl2(g) + 2HCl(g)
So, its standard enthalpy will be:
ΔH∘rxn = (1)ΔH∘f(CoCl2 (g)) + (2)ΔH∘f(HCl(g)) − (1)ΔH∘f(H2O(l)) − (1)ΔH∘f(CCl4(l))
using the values from table:
ΔH∘rxn = - 218.8 KJ/mol + (2)(- 92.3 KJ/mol) - (- 285.8 KJ/mol) - (- 139.5 KJ/mol)
ΔH∘rxn = 21.9 KJ/mol
B.
Reaction given to us is:
2A + B ⇌ 2C + 2D
So, its standard enthalpy will be:
ΔH∘rxn = (2)ΔH∘f(C) + (2)ΔH∘f(D) − (2)ΔH∘f(A) − (1)ΔH∘f(B)
using the values from table:
ΔH∘rxn = (2)181 KJ/mol + (2)(- 523 KJ/mol) - (2)(- 225 KJ/mol) - (- 337 KJ/mol)
ΔH∘rxn = 103 KJ/mol
C.
Balanced equation for combustion of ethanol is:
C2H5OH + 3O2 → 2CO2 + 3H2O
Answer: is A B abd C
Which explains how the technology of probeware has increased scientific inquiry?
Answer:
~ Probeware can collect large amounts of data in a short amount of time.
~Probeware can display data quickly.
~Probeware can collect data that is very precise.
Probeware can be used to map all parts of the universe. WRONG.WRONG.
~Probeware can store large amounts of data in a small space.
~Probeware can analyze data
PLEASE HELP ME !!!!!!!!!!!!!!
Name: Period; Date:
Problem:
Determine the amount of energy (heat) in Joules and Kcal required to raise the temperature 0f 98.5 grams water from 37.0 0C to 75.0 0C.
Restate the problem (in your own words & all relevant information included).
Model that best represents the problem. Draw and label.
Steps to solve the problem (include formula, known and unknown variables, etc)
Solution and final answer. (show cancellation of units).
Reflection: Must at least have 3 sentences.
Answer:
Explanation:
The missing components in the table to the right are indicated with orange letters. use the periodic table and the tools bar to fill in the corresponding values.
a
b
c
d
Answer:
A: 349.0
B: 3.16
C: 1.31
D: 0.93
Explanation:
The missing components in the table to the right are indicated with orange letters. By using the periodic table and the tools bar corresponding values are (A) 349 (B) 3.16 (C) 1.31 and (D) 0.93.
What is Electron Affinity ?The electron affinity of an atom or molecule is defined as a energy released when electrons added to outermost shell. Electron affinity increases from left to right across a period.
What is Electronegativity ?Electronegativity is defined as the tendency of atom attract the bonded pair of electrons of covalent bond to itself. To measure the electronegativity Pauling scale is used.
The electron affinity value of chlorine is 349 (kJ/mol). The electronegativity value of chlorine is 3.16. The electronegativity value of magnesium is 1.31. The electronegativity value of Sodium is 0.93.
Thus from the above conclusion we can say that The missing components in the table to the right are indicated with orange letters. By using the periodic table and the tools bar corresponding values are (A) 349 (B) 3.16 (C) 1.31 and (D) 0.93.
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A homerun in a baseball game was measured at 450 feet. How many meters is this equal to?
Answer:
137.16
Explanation:
It takes 36 minutes for 100-grams of a radioactive substance to decay to 25-grams. What is the half-life of this substance?
Answer:
18 minutes is the half life
What best explains whether bromine (Br) or neon (Ne) is more likely to form a covalent bond?
On left, a purple circle labeled Br surrounded by 4 concentric circles. The inner circle has 2 small green spheres. The second circle has 8 small green spheres. The third circle has 18 small green spheres. The fourth circle has 5 small green spheres. On right, a purple circle labeled Ne surrounded by 3 concentric circles. The inner circle has 2 small green spheres. The middle circle has 8 small green spheres. The outer circle has 8 small green spheres.
Bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and already fulfills the octet rule.
Bromine forms covalent bonds because it has many electron shells, but neon has only two electron shells and is tightly bound to its electrons.
Neon forms covalent bonds because it can share its valence electrons, but bromine has seven valence electrons and can gain only one more electron.
Neon forms covalent bonds because it has only two electron shells, but bromine has many electron shells and will lose electrons in order to fulfill the octet rule.
Mark this and return
Answer:
Bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and already fulfills the octet rule. Neutral atoms coming together to share electrons.
Hoped this helped
Answer:
the answer is A btw
Explanation:
WILL GIVE BRAINLYEST!!!!!The number at the bottom of Silicon on the periodic table is 28.086. This number is the element's _____________.
silicon
14
SI
28.086
Question 10 options:
atomic weight
symbol
atomic number
electron number
Answer:
atomic weight
Explanation:
its atomic weight becuase if it a number on the peroidic table its going to be the atomic weight
What is an isotope and how does their abundance in nature differ from element to element
Answer:
isotopes, there elements with a diffrent type atomic weight then the original, usally due to a higher amout of neutrons than the original. Some Isotopes are just as useable as the normal versions, but in some cases, such as Uranium, they can be even more radioactive than the original form
Wavelength measures the length of an
individual color
individual sound
individual wave
all radiation on earth
Answer: individual wave
Hope this helps! :)
How many grams of H2 are needed to react with 47 grams of N2 to produce 200 grams of NH3?
The term mole concept is used here to determine the mass of hydrogen. The mass of hydrogen required to produce 200 g of ammonia is 35.28 g.
What is a mole?One mole of a substance is defined as that quantity of it which contains as many entities as there are atoms exactly in 12 g of carbon - 12. The formula used to calculate the number of moles is:
Number of moles = Given mass / Molar mass
The balanced equation is:
N₂ + 3H₂ → 2NH₃
3 moles of H₂ gives 2 moles of NH₃
The molecular mass of NH₃ is 17 g/mol
n = 200 / 17 = 11.76 mol
1 mole comes from 1.5 moles of H₂
So 11.76 mol comes 1.5 × 11.76 moles H₂ = 17.64 moles of H₂
Mass of H₂ = 17.64 × 2 = 35.28 g
Thus the mass of H₂ needed is 35.28 g.
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8. In the nucleus, I tell cells what to do and how to change. 9. The fastest growing organ in humans is the
Answer:
skin is the fastest growing organ in human beings.
I AM GETTING TIMED! PLEASE HELP ME!!
Explanation:
no.A (He) I think.............
The modern periodic table is organized by:
O atomic number
O number of protons in each element
O atomic weight
hing
chemical properties
Answer:
Atomic number
Explanation:
The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.
The Modern periodic table is organized on the basis of increasing atomic Number.
calculate the frequency in hertz of electromagnetic radiation that has a wavelength of 720.0 nm. (c= 3.00 X 10^8 m/s)
Answer:
[tex]f=216s^{-1}=216Hz[/tex]
Explanation:
Hello.
In this case, the relationship between wavelength, speed of light and frequency is:
[tex]\lambda=\frac{c }{f}[/tex]
It means that solving for the frequency, we obtain:
[tex]f=c*\lambda[/tex]
Thus, for the given 720-nm wavelength and the speed of light, the frequency is:
[tex]f=3.00x10^8\frac{m}{s}*720.0nm*\frac{1x10^{-9}m}{1nm}\\ \\f=216s^{-1}=216Hz[/tex]
Best regards.
The frequency in hertz of the electromagnetic radiation is [tex]4.12 \times 10^{14}[/tex] Hertz.
Given the following data:
Wavelength = 720.0 nanometers.Speed = [tex]3.00 \times 10^8[/tex] m/sConversion:
1 nanometer = [tex]1 \times 10^{-9}[/tex] meter
720 nanometer = [tex]7.2 \times 10^{-7}[/tex] meter
To find the frequency in hertz of the electromagnetic radiation:
Mathematically, the frequency of an electromagnetic radiation is given by the formula:
[tex]Frequency = \frac{speed}{wavelength}[/tex]
Substituting the given parameters into the formula, we have;
[tex]Frequency = \frac{3.00 \times 10^8}{7.2 \times 10^{-7}}[/tex]
Frequency = [tex]4.12 \times 10^{14}[/tex] Hertz
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Based on the given examples, what do you think is the main characteristic
of a liquid?
Characteristics of Liquids
Liquids have definite volume, but indefinite shape. They are free to form droplets and puddles when they are not inside a container. When a liquid is inside a container, it will take its shape. Unlike gases, a liquid will not change its volume to spread out and completely fill a container.
Suppose you prepare 1.00 L of an aqueous solution containing 1.00 mol Na2CO3. What is the concentration of the Na ion in the solution
Answer:
69
Explanation:
and identify the type
of reaction
Fe2O4 + Al → A1,03 + Fe
If an atom has a mass of 40 amu, which of the following MUST be true?
a. There are 20 protons in this atom.
b. There are less than 40 protons in this atom.
c. There are exactly 40 protons in this atom.
d. There are 40 electrons in this atom.
Answer:
b. There are less than 40 protons in this atom.
Explanation:
Hello.
In this case, given the information we have available in the periodic table, we can infer that the number of both protons and electrons of neutral atoms is equal to the atomic number, not the atomic mass which is actually given. Nevertheless, the number neutrons are computed by knowing the atomic mass and the atomic number via:
[tex]neutrons=atomic\ mass -atomic \ number[/tex]
It means that the atomic mass is greater than the atomic number or the amount of both protons and electrons. In such a way, we can infer that the answer is b. There are less than 40 protons in this atom since the number of neutrons must be positive.
Best regards.
If the above quantum numbers describe two different electrons
in an oxygen atom, and the angular momentum number X is 1,
what is the possible number of Y?
Answer:
0
Explanation:
If no number occupies it it’s 0
A cube of gold-colored metal with a volume of 64 cm has a mass of 980 g. The density of pure gold is 19.3 g/cm³. Is the metal pure gold?
Answer:
No, the metal is not pure gold because density is equal to mass divided by volume and in this case we end up with about 15.3, making this metal less dense than gold.
Explanation:
The definition of density allows to find the answer of whether the metal is gold:
As the density of the material is less than the gold density . This is not pure gold
Density is defined as the mass of a body divided by its volume, it is a very important physical characteristic of the body since it is invariant.
[tex]\rho = \frac{m}{V}[/tex]
Where ρ is the density, m the mass and V the volume
They indicate that the object's mass is 980 g and it has a volume of 64 cm³, ask if it is made of pure gold.
The systems of units are systems of measurements to exchange magnitude without inconveniences, the most used system is the intentional system of measurements (SI), we re-educate the magnitudes to this system
m = 980 gr ([tex]\frac{1kg}{1000g}[/tex] ) = 0.980 kg
V = 64 cm³ [tex]( \frac{1m}{100 cm} )^3[/tex] = 64 10⁻⁶ m³
let's find the density of the object
ρ = [tex]\frac{0.980 }{64 \ 10^{-6} }[/tex]
ρ = 15.3 10³ kg/m³
The tabulated gold density is 19.3 10³ kg/m³
We can see that the density for the body is less than the gold density.
In conclusion with the definition of density we can find the answer for if the metal is gold is:
As the density of the material is less than the gold density. This is not pure gold
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Washing soda, a compound used to prepare hard water for washing laundry, is a hydrate, which means that a certain number of water molecules are included in the solid structure. Its formula can be written as Na2CO3⋅χH2O where x is the number of moles of H2O per mole of Na2CO3 When a 2.558-g sample of washing soda is heated at 125∘C all the water of hydration is lost, leaving 0. 948 g of Na2CO3.What is the value of x?
Answer:
X = 10
Explanation:
First, we need to calculate the moles of Na₂CO₃ in the 0.948g. Then, the moles of water based on the difference of masses. X will be the ratio of moles of water and moles of sodium carbonate.
Moles Na₂CO₃ (Molar mass: 105.99g/mol):
0.948g * (1mol / 105.99g) = 8.944x10⁻³ moles
Moles H₂O (Molar mass: 18.02g/mol):
2.558g - 0.948g = 1.61g of water
1.61g * (1mol / 18.02g) =0.08935 moles
The ratio, X, is:
0.08935mol / 8.944x10⁻³ moles
X = 10Consider the combustion of methane (as represented by the following equation). This is the reaction that occurs for a Bunsen burner, which is a source of heat for chemical reactions in the laboratory.
CH4(g) + 2O2(g) →CO2(g) + 2H2O(g)
For the system at chemical equilibrium, which of the following explains what happens if the temperature is raised?
a. The equilibrium is shifted to the right and the value of K increases.
b. The equilibrium is shifted to the right and the value of K decreases.
c. The equilibrium is shifted to the left and the value of K decreases.
d. The equilibrium is shifted to the left and the value of K increases.
e. The equilibrium is shifted but the value of K stays constant.
Answer:
The correct answer is - option C. The equilibrium is shifted to the left and the value of K decreases.
Explanation:
The combustion of the methane produces water vapor, carbon dioxide when burns in presence of oxygen. This reaction also releases heat and light when combustion occurs.
CH4(g) +2O2(g)-----> CO2(g)+ 2H2O(g) + Heat
As this reaction releases the heat which means it is an exothermic reaction and as if the temperature increase, the equilibrium constant decreases, and as it decreases the equilibrium shifted to the left.
Thus, the correct answer is - option C.
Answer: option choice C
Explanation:
In a certain chemical reaction, 2 solid Mg atoms bond with O2 gas to produce solid
Mgo. Which of the following reaction equations correctly describes this reaction?
A) 2Mg (s) + O2(g) – Mgo (1)
O B) 2Mg (s) + O2 (g) – 2Mgo (s)
Sey
C) Mg (s) + 202 (g) – Mgo (s)
D) Mg (g) + O2 (s)
-
2MgO (g)
Answer:
Option B. 2Mg(s) + O2 (g) —> 2MgO (s)
Explanation:
From the question given above,
We were told that:
2 solid Mg atoms bond with O2 gas to produce solid MgO.
This can be represented by an equation as follow:
2Mg(s) + O2 (g) —> MgO (s)
Next, we shall balance the above equation as follow:
2Mg(s) + O2 (g) —> MgO (s)
There are 2 atoms of Mg on the left side and 1 atom on the right side. It can be balance by putting 2 in front of MgO as shown below:
2Mg(s) + O2 (g) —> 2MgO (s)
Now, the equation is balanced.
Answer:2 Mg (s)+ O2 (g)= 2MgO(s)
Explanation:
I really need this fast
Answer:
b
I think it's me because a ball of golf into some races as it rolls up increases put
Value: 4
The equation of a line for Data Set 4 is y = 0.14*x + -0.0398 where y is the absorbance
values and x is the concentration in mg/mL. This was created using data from known
concentrations and absorbances. Now we can use this equation of a line to determine
the concentration of an unknown solution.
Determine the concentration of an unknown solution that has an absorbance of 0.622.
Concentration =
mg/mL. Use two sig figs in your final answer
= 1/2
Next >
Answer:
x = 4.73
Explanation:
Given
y = 0.14x - 0.0398
Required
Find x when y = 0.622
To do this, we first substitute 0.622 for x.
y = 0.14x - 0.0398 gives
0.622 = 0.14x - 0.0398
Solve for 0.14x
0.14x = 0.622 + 0.0398
0.14x = 0.6618
Solve for x
x = 0.6618/0.14
x = 4.7271428571
x = 4.73 approximated
1. You return to the car from an all-day shopping spree at the mall.
Your favorite CD, which you left on the dashboard, is now stuck.what could be the experiment?
Answer:
it could be a bad experience
Explanation:
because the left the cd on the dashboard
which organelle helps to break down substances?
Answer:
Lysosomes
Explanation:
As a teacher, Kenneth must prepare for his classes and teach his students.
Preparing for classes and teaching students is known as
A. prestige
B. a social role
C. structure
D. status
Answer:
The answer is a social role.
Explanation:
Apex
Answer:
a social role :)
Explanation: