Answer:
6.55 x 10^22 atoms K
Explanation:
Convert from grams to moles (using K molar mass)
K molar mass = 39.098 g/mol
4.25 g K x 1 mol K / 39.098 g K
[grams cancel out]
= 0.1087 mols K
Convert from moles to atoms (using Avogadro's number)
Avogadro's number = 6.0221 x 10^23
0.1087 mols K x 6.0221 x 10^23 atoms K / 1 mols K
[mols cancel out]
= 6.545987 x 10^22
[with proper significant digits.....]
= 6.55 x 10^22 atoms K
Iron ore exists as Fe2O3. In order to remove the oxygen and generate pure iron, the oxygen must be transferred to another molecule. Carbon monoxide can be mixed with iron ore and carbon dioxide is generated. Carbon monoxide is produced in the combustion of carbon with limited oxygen. Calculate the value of ΔS° for the oxidation of carbon to carbon monoxide,
2C (s, graphite) + O2 (g) --> 2CO (g)
A. +179.4 J/mol K
B. +408.6 J/mol K
C. -408.6 J/mol K
D. +395.8 J/mol K
What is the volume of 1.00 kg of mercury?
Answer:0.074 L
Explanation:
To determine the percentage of bromide in a mixture containing a soluble bromide salt, the procedure from Experiment 10 is used except the bromide is precipitated with aqueous lead (II) nitrate, Pb(NO3)2, forming PbBr2(s). Initially, a 0.5014 g sample of an unknown bromide salt is dissolved in water. Excess Pb(NO3)2 is added to the solution to quantitatively precipitate the bromide from the solution. The resulting mixture is filtered through a piece of filter paper weighing 1.3258 g. After several days of drying, the filter paper and precipitate weighed 1.7895 g. Calculate the percent bromide in the original sample.
Answer:
40.27% Bromide in the original sample
Explanation:
The reaction of bromide ion, Br- with Pb(NO3)2 is:
2 Br- + Pb(NO3)2 → PbBr2(s)
Where the precipitate produced is PbBr2
To solve this question we must find the moles of PbBr2 filtered using its mass. Twice these moles we can find the moles of Br- and its mass. Percent bromide is:
Mass Bromide / Mass Sample (0.5014g) *100
Mass PbBr2:
1.7895g - 1.3258g = 0.4637g PbBr2
Moles -Molar mass: 367.01g/mol-
0.4637g PbBr2 * (1mol / 367.01g) =
0.001263 moles PbBr2 * (2mol Br / 1mol PbBr2) = 0.002527 moles Br
Mass Br -Molar mass: 79.904g/mol-
0.002527 moles Br * (79.904g / mol) =
0.2019g Br
Percent Bromide:
0.2019g Br / 0.5014g * 100 =
40.27% Bromide in the original sampleWhich of the following compounds would have the lowest
solubility?
ОНczА
O Nm3R
O Bv3(AX)2
O Hn(EX2)2
O MRD2
If you have a solution that is 15 percent by mass of KCl in benzene, what is the new boiling point?
Answer:
https://www.chegg.com/homework-help/questions-and-answers/1-10-points-solution-15-percent-mass-kcl-benzene-new-boiling-point--901-c-b-921-c-c-821-c--q63751186
Explanation: Thats your answer
In osmosis: a. Knowing the osmotic pressure can help determine the molar mass of a solute dissolved in a solvent. b. The semipermeable membrane is used to change the freezing and melting points of a solution. c. Solutions cannot have identical osmotic pressures. d. Temperature does not affect the osmotic pressure of a solution. e. At least two of the above statements are correct.
Answer:
a)
Explanation:
Osmosis is a process in which there is movement of solvent molecules through a semipermeable membrane to wards the higher concentration of solute or lower concentration of solvent from a lower concentration of solute molecule. Osmosis can occur in different liquids and even in gases.
Also, in osmosis knowing the osmotic pressure can help determine the molar mass of a solute dissolved in a solvent.
in a hypothetical element ,two energy levels are separated by an energy of 282kj mol-1 . what wavelength of light (in nma) is evolved for an electron to change between these two levels?
Answer:
7.05 × 10⁻²² nm
Explanation:
Step 1: Given and required data
Energy evolved when a mole of electrons changes between the 2 levels (E): 282 kJPlanck's constant (h): 6.63 × 10⁻³⁴ J.sSpeed of light (c): 3.00 × 10⁸ m/sStep 2: Calculate the wavelength (λ) of the light evolved
We will use Planck-Einstein's relation.
E = h × c/λ
λ = h × c/E
λ = (6.63 × 10⁻³⁴ J.s) × (3.00 × 10⁸ m/s)/(282 × 10³ J) = 7.05 × 10⁻³¹ m
We will convert λ to nm using the conversion factor 1 m = 10⁹ nm.
7.05 × 10⁻³¹ m × 10⁹ nm/1 m = 7.05 × 10⁻²² nm
how to write an article?
Answer:
essay typer.com click the first link
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On which of the following factors does the amount of energy absorbed by an endothermic reaction depend?
1. Number of reactants
2. Physical state of the reactant
3. Sum of the potential energy of the reactants and products
4. Difference in the potential energy of the reactants and products
Answer:
Option 3 and 4
Explanation:
In an endothermic reaction, the potential energy of the system increase. The potential energy of the reactant is less as compared to the potential energy of the products and hence additional energy is required to produce products.
The potential energy of the reactants depend on their chemical state and not the physical state. Hence, option 2 is not correct. Also, the number of reactant do not make any significant impact on the determination of potential energy of reactants. Thus, option 1 is also incorrect
PLEASEEE HELP!!!! ILL MARK BRAINLESS FIRST PERSON!!!!!
Answer:
A. it should have a cell wall to give it structure
Which of the following solutions is the most dilute.
a. 0.32 M
b. 1.5 M
c. 2.5 mol / L
d. 0.23 mol / L
e. 0.23 mol / L
Answer:
d and e
Explanation:
We have 5 solutions with different molar concentrations, that is, the quotient between the number of moles of solute and the liters of solution. This can be expressed as mol/L or M. The most dilute would be the one having the less number of moles of solute per liters of solution, that is, solution d or e, which have the same concentration. If we order them from the most diluted to the most concentrated, we get:
d = e < a < b < c
Definition: These are the layers of rock or soil that are distinguishable from other layers that have been
laid down upon one another over the history of the earth.
01)
Term: Type term here
Strata are the layers of rock or soil that are distinguishable from other layers that have been laid down upon one another over the history of the earth.
What is a Strata?A strata is the horizontal layer of rocks or sedimentary rocks that are laid upon another or arranged one on top of another that is separated by adjacent beds planes or layers.
Therefore, Strata are the layers of rock or soil that are distinguishable from other layers that have beenlaid down upon one another over the history of the earth.
Learn more about strata below.
https://brainly.com/question/25817019
Question 4 (10 points)
If a sollition has a pOH of 5.2 the [OH-] of the solution is
оа
6x 10-6 M
Ob
6.3 x 10-6 M
Oc
1.58 x 10-5M
Od
2x10-5M
Answer:
Explanation:
g A closed-end manometer was attached to a vessel containing argon. The difference in the mercury levels in the two arms of the manometer was 9.60 cm. Atmospheric pressure was 783 mm Hg. The pressure of the argon in the container was ________ mm Hg. Selected Answer: Incorrect 773 Answers: 882 793 661 773 Correct 96.0
Answer:
Answer: 882mmHg
Explanation:
In a closed-end manometer, the gas added is under a pressure that is measured against atmospheric pressure. The difference in pressure between both gases is equal to the difference in mercury levels. Thus, the pressure of the argon can be:
783 mmHg - 96.0mmHg = 687mmHg
783 mmHg - 96.0mmHg = 879mmHg
Based on the options, the possible answer (The nearest to the second value) is:
Answer: 882mmHgAnswer both of these true or false correctly
brainliest if correct
Answer:
There both true.
Explanation:
Hope this helps
Answer:
The first one is True
The second one is false
Explanation:
Consider the energy diagram below.
AY
B
Free Energy
Reaction Progression
Which line indicates a higher reaction rate?
A because it has a lower activation energy.
B because it has a lower activation energy.
Answer:
B because it has a lower activation energy.
Explanation:
Just took the test
If 0.60 L of a solution contains 6.6 g of NaBr, what is its molar concentration?
Answer:
Molarity = moles ÷ liters
to get moles of NaBr divide grams of NaBr by its molar mass (mass of Na + mass of Bromine)
Na = 22.989769
Br = 79.904
molar mass of NaBr = 102.893769
6.6g ÷ 102.893769 = 0.064143826 moles of NaBr
0.064143826 moles ÷ 0.60 liters = 0.1069 molar concentration or 11 %
You studied the body of someone who died in their sleep and found that your assistant accidentally left the body facedown while you were away. Knowing that the person, in life, slept face-up, you can see that the blood is pooled at their backside. What has your assistant accidentally revealed about the victim?
A. The victim probably died only a few hours before the assistant’s accident
B. The victim was probably poisoned to death
C. The victim died at least 8 hours before the body was flipped
D. The victim was probably moved after they had died by someone else—or they didn’t die in their sleep!
Answer:
D
Explanation:
The ionization potential of Be atom is more than expected because it has -
(a) half filled valence p orbitals
(b) fully filled valence s orbitals
(c) both a and b
Answer:
(b) fully filled valence s orbitals
Explanation:
Electron configuration of Be: 1s22s2
2s2 is fully filled
How many moles are in 60.05 g of carbon
Answer:
moles =60.05/12
moles=5.0041
moles=5(approx)
1.6 x 1023 atoms of Be, how many moles of Be are there?
Answer:
1 mole.
Explanation:
1.6x10^23 = NA = 1 mole of any substance.
a warm air is rising as cooler air es in to take its place. what is the name for that?
Answer:
convection
hope this helps
have a good day :)
Explanation:
Suppose you have a solution that might contain any or all of the following cations: Cu 2, Ag , Ba 2, and Mn2 . The addition of HBr causes a precipitate to form. After the precipitate is filtered off, H2SO4 is added to the supernate, and another precipitate forms. This precipitate is filtered off, and a solution of NaOH is added to the supernatant liquid until it is strongly alkaline. No precipitate is formed. Which ions are present in each of the precipitates
Answer:
Ag⁺, Ba²⁺,
Explanation:
We can solve this question using the solubility rules:
When an Halide as Br- is added to a solution, the ions that can be precipitate are Ag⁺, Hg₂²⁺ and Pb²⁺.
That means the first ion present is Ag⁺
When sulfates, SO₄²⁻ are added, the ions that precipitates are: Ag⁺, Ca²⁺, Sr²⁺, Ba²⁺, Hg₂²⁺ and Pb²⁺
The second ion present is Ba²⁺
Hydroxides of Cu²⁺ and Mn²⁺ are insolubles but as no precipitate are formed when the solution is strongly alkaline those ions are not present.
Colligative properties of solutions include all of the following except: a. an increase in the osmotic pressure of a solution upon the addition of more solute b. elevation of the boiling point of a solution upon addition of a solute to a solvent c. an increase of reaction rate with increase in temperature d. depression of the freezing pont of a solution upon addition of a solute to a solvent e. depression of vapor pressure upon addition of a solute to a solvent
Answer:
Option C, an increase of reaction rate with increase in temperature
Explanation:
Colligative properties are as follows
a) Decrease of vapor pressure
b) Increase of boiling point
c) Reduction of freezing point
d) Increase of osmotic pressure
There is no impact on reaction rate and hence it is not a colligative property.
Thus, option c is the right choice
An increase of reaction rate with increase in temperature isn't an example
of colligative properties of solutions
Colligative properties of solutions depend on the ratio of the number of
solutes to that of the solvent(concentration) and not on the nature of the
substances involved.
Examples of colligative properties include vapor pressure lowering, boiling
point elevation, freezing point depression, and osmotic pressure. Increase of
reaction rate with increase in temperature is therefore not an example of
colligative properties of solutions.
Read more on https://brainly.com/question/24260365
Ar
Si
K
Al
An atom of which element in the table above has the highest
number of neutrons?
Answer: ar
Explanation:
During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.
What is the amount of the leftover reactant?
0.74 grams of methane
0.89 grams of methane
1.22 grams of oxygen
1.45 grams of oxygen
Answer:d
Explanation:
Bolt can run at a top speed of 28 mph.
what it meant by executive mention the function of Executive
[tex]\huge{\textbf{\textsf{{\color{pink}{An}}{\red{sw}}{\orange{er}} {\color{yellow}{:⌐■-■}}}}}[/tex]
Definition:-
The organ of government that primarily looks after the function of implementation and administration is called the executive.
Function:-
Executive is the branch of government responsible for the implementation of laws and policies adopted by the legislature.
ThanksHope it helps.What is the Molar mass of zinc
Answer:
the molar mass of zinc is 65.38u or 65.38 grams(g).
5
Which of the following is a factual statement about
hormones?
A They are the sole cause of mood swings
B
They cause boys' and girls' bodies to develop
C
They are a type of blood cell
D They are extremely difficult to deal with
Answer:
They cause boys' and girls' bodies to develop