Answer:
The sun will appear to rise and set more slowly
have a nice day! (^o^)
A chemist is studying the rate of the Haber synthesis: N2 + 3H2 2NH3
Starting with a closed reactor containing 1.25 mol/L of N2 and 0.50 mol/L of H2, the chemist finds that the H2 concentration has fallen to 0.25 mol/L in 44 seconds.What is the N2 concentration after 44 seconds?
Answer:
1.17 M
Explanation:
Step 1: Write the balanced equation
N₂ + 3 H₂ ⇒ 2 NH₃
Step 2: Calculate the rate of disappearance of H₂
We will use the following expression.
rH₂ = - Δ[H₂]/t = - (0.25 M - 0.50 M)/44 s = 0.0057 M/s
Step 3: Calculate the rate of disappearance of N₂
The molar ratio of N₂ to H₂ is 1:3.
0.0057 mol H₂/L.s × 1 mol N₂/3 mol H₂ = 0.0019 mol N₂/L.s
Step 4: Calculate the final concentration of N₂
We will use the following expression.
[N₂] = [N₂]₀ - rN₂ × t
[N₂] = 1.25 mol/L - 0.0019 mol/L.s × 44 s
[N₂] = 1.17 M
The gas carbon dioxide is a pure substance. Which of the following is true about carbon dioxide? (5 points)
Select one:
a. Carbon and oxygen are chemically bonded in it.
b. Carbon and oxygen retain their original identity in it.
c. It can be separated into carbon and oxygen using physical methods.
d. The proportion of carbon and oxygen is different in different samples of the gas.
Answer:
Carbon and oxygen are chemically bonded in it.
Explanation:
The other answer choices do not apply for compounds, but rather for mixtures instead.
a sample of fully saturated clay weighs 1350 g in its natural state and 975 g after drying. what is the natural water content of the soil
Answer:
The soil has a percentage of water by mass of 27.8 %.
Explanation:
Keeping in mind that
Mass of Clay = Mass of water + Mass of Dry Soilwe can calculate the mass of water:
1350 g = Mass of Water + 975 gMass of Water = 375 gWe can then calculate the mass percentage of water in the soil:
375 / 1350 * 100% = 27.8 %How much heat must be used to raise the
temperature of 180. g water from 19° C to 96°C?
The specific heat of water is 4.18 J/gºC.
Answer:
Q = 57934.8 J
Explanation:
Given data:
Mass of water = 180.0 g
Initial temperature = 19°C
Fina temperature = 96°C
Specific heat capacity of water = 4.18 J/g.°C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 96°C - 19°C
ΔT = 77°C
Q = 180.0 g×4.18 J/g.°C×77°C
Q = 57934.8 J
An element has five isotopes. Calculate the atomic mass of this element using the information below. Show all your work. Using the periodic table, identify the element this is likely to be and explain your choice. (18 pts)
A) Isotope 1 – mass: 64 amu; percent abundance: 48.89%
B) Isotope 2 – mass: 66 amu; percent abundance: 27.81%
C) Isotope 3 – mass: 67 amu; percent abundance: 4.11%
D) Isotope 4 – mass: 68 amu; percent abundance: 18.57%
E) Isotope 5 – mass: 70 amu; percent abundance: 0.62%
Answer: Sol:-
Data provided in the question is :-
Atomic mass of isotope -1 = 64 amu
Atomic mass of isotope -2 = 66 amu
Atomic mass of isotope -3 = 67 amu
Atomic mass of isotope -4 = 68 amu
Atomic mass of isotope - 5 = 70 amu
Percentage abundace of isotope - 1 = 48.89 %
Percentage abundance of isotope -2 = 27.81 %
Percentage abundance of isotope - 3 = 4.11%
Percentage abundance of isotope-4 = 18.57%
Percentage abundance of isotope - 5 = 0.62 %
Formula used :-
Average atomic mass of an element =[ {(atomic mass of isotope-1 * percentage abundance of isotope-1) + ( atomic mass of isotope-2 * percentage abundance of isotope -2) + ( atomic mass of isotope -3 * percantege abundance of isotope-3 ) + ( atomic mass of isotope-4 * percentage abundance of isotope-4) + (atomic mass of isotope-5 * percentage abundance of isotope-5)} / 100]
Calculation :-
Put all the value in the formula :-
Average atomic mass of an element = [{(64 * 48.89) + (66 * 27.81) + (67 * 4.11) + (68 * 18.57) + (70 * 0.62)} / 100] amu
= [{(3128.96) + (1835.46) +(257.37) + (1262.76) + (43.4)} / 100] amu
= {(6528.04) / 100} amu
= 65.2804 amu
Average atomic mass of an element is = 65.2804 amu
Then this mass is approximatly equal to atomic mass of zinc so this element would be zinc
atomic mass of zinc = 65.38 \approx 65.2804 amu
Determine where each type of cleaning solution should be discarded after use. Solvent used to rinse chemicals out of a beaker ______Acid solution used to clean a crucible _________Water used to rinse detergent out of a flask ________
Answer:
Acidic solution used to clean a crucible
Explanation:
This liquid dissolves alcoholic solvents such as crucible, that is why it was selected as the ideal for cleaning.
Although it would be ideal to know in detail which chemical compound is the one you want to clean so that the cleaning technique has better effectiveness.
WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.
The disposal containers in a lab can be used for recycling, disposal of trash, glassware disposal box, sharp box, etc.A waste container is a container usually used to dispose of waste in a laboratory, which may be made of plastic.Moreover, a laboratory sink can be used to wash tools and/or hands without the hazard of damaging the health or the sink.In conclusion, WASTE CONTAINER refers to the solvent used to rinse chemicals out of a beaker, and it also refers to the acid solution used to clean a crucible. Water used to rinse the detergent out of a flask refer to the SINK.
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A chemical reaction takes place inside a flask submerged in a water bath. The water bath contains 6.50kg of water at 24.2°C. During the reaction 88.2kJ of heat flows out of the flask and into the bath.Calculate the new temperature of the water bath. You can assume the specific heat capacity of water under these conditions is 4.18·J·g−1K−1. Be sure your answer has the correct number of significant digits.
Answer:
27.4°C
Explanation:
Using the equation:
Q = m*C*T
Where Q is heat added,
m the mass of water
C specific heat of water (4.18J/g°C)
And T the increase in temperature
We can solve for the increase in temperature and thus, the final temperature of water:
Q = 88200J; m = 6500g:
88200J = 6500g*4.18J/g°C*T
3.2°C = T = increase in temperature
Final temperature is:
24.2°C + 3.2°C =
27.4°CWhen Elsa freezes things, is it an example of an exothermic or
endothermic reaction? Explain.
Answer:
endothermic reaction
Explanation:
When Elsa from Frozen freezes things, it is an example of an endothermic chemical reaction.
An endothermic involves a reaction in which heat is absorbed from the surrounding. Hence the surrounding becomes colder at the end of the the change.
So, Elsa draws heat from the environment and this causes the environment to be colder and things that are in contact with her.
In the kinetic theory, the particles in a gas
A. move independently of each other.
B. have attractive and repulsive forces.
C. move slowly.
D. are relatively close together.
Answer:
Im pretty sure its B
Sorry if Im wrong
Explanation:
Have a wonderful day!!!<3
Answer:
The only answer that could apply to a gas is A
Explanation:
7. Use the concepts of relative abundance and relative weight to explain why carbon has an atomic mass of 12.011 amu when there are three isotopes of carbon weighing 12 amu, 13 amu and 14 amu. Why is the atomic mass not 13?
The uncertainties of the delta measurements and the uncertainty of the atomic weight derivedfrom the best measurement of isotopic abundances constrain the number of significant figures in theatomic-weight values of the upper and lower bounds. For carbon, the fifth digit after the decimal pointis uncertain because of the uncertainty value of 0.000 027. Therefore, the number of significant digitsin the atomic-weight value is reduced to four figures after the decimal point. The Commission may rec-ommend additional conservatism and reduce the number of significant figures further. For the lowerbound of carbon, 12.009 635 is truncated to 12.0096. For an upper bound, the trailing digit is increasedto ensure the atomic-weight interval encompasses the atomic-weight values of all normal materials. Inthe case of carbon, the upper bound is adjusted from 12.011 532 to 12.0116 to express four digits afterthe decimal point. The lower and upper bounds are evaluated so that the number of significant digits ineach is identical. If a value ends with a zero, it may need to be included in the value to express therequired number of digits. The following are examples of lower and upper atomic-weight bounds foroxygen that could be published by the Commission in its various tables.
---------------------------
Extracted from" Atomic weights of the elements 2009 (IUPAC Technical Report)"
which section from the article most emphasizes the role of technological development in the discovery of cells
Answer:
B. The microscope paved the way
Explanation:
This section from the article, "History of the Cell: Discovering the Cell", that emphasizes the role of technological development in the discovery of cells, is the subheading, "The microscope paved the way". In this subheading, the author narrated how Robert Hooke improved the existing microscope, and was able to discover the cell through it.
Further improvement of the simple microscope by Antonie van Leeuwenhoek led to the discovery of bacteria and protozoa.
Find the mass in grams of 1.38 moles of Sr
Answer:
116.78 grams.
Explanation:
1 mol of Strontium (Sr) = 87.62 grams
1.38 mol of Strontium = x
Cross Multiply
1 * x = 1.38 * 87.62
x = 116.78 grams
A gray element that borders on the zigzag line of the periodic table, is ductile and malleable, but is not a very good conductor of heat or electricity is known as which of the following?
A. metal
B. halogen
C. metalloid
D. nonmetal
A gray element that borders on the zigzag line of the periodic table, is ductile and malleable, but is not a very good conductor of heat or electricity is known as metalloid. The correct option is option C.
What is periodic table?In chemistry, a periodic table is an orderly arrangement of each of the chemical elements along order of atomic number is, the total amount of protons inside the atomic nucleus.
Whenever the chemical elements stand grouped in this manner, there is a recurrent pattern in their characteristics known as the "periodic law," in which elements within a single column (group) exhibit comparable qualities. A gray element that borders on the zigzag line of the periodic table, is ductile and malleable, but is not a very good conductor of heat or electricity is known as metalloid.
Therefore, the correct option is option C.
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3. How much heat (in kl) is released when 1.65 mol NaOH(s) is dissolved in water? (The molar heat of solution of NaOH is -445.1 kJ/mol.)
a. -1.36x 10-3 kJ
b. -7.34 x 10^2 km
c. -2.69 x 10^1 km
d. -2.80 x 10^2 km
The heat released : b. -7.34 x 10² kJ
Further explanationGiven
1.65 mol NaOH
The molar heat of solution of NaOH is -445.1 kJ/mol
Required
Heat released
Solution
ΔH solution = Q : n
ΔH solution = enthalpy of solution(-=exothermic, +=endothermic)
Q = heat released/absorbed
n = moles of solute
Input the value :
Q = ΔH solution x n
Q = -445.1 kj/mol x 1.65 mol
Q = -734.415 kJ
Which element in group 17 has the highest ionization energy
Answer:
fluorine
Explanation:
it has the highest electronegativity in the group and in the periodic table
What is an ecosystem? ?
Answer:
An ecosystem is a community or group of living organisms that live in and interact with each other in a specific environment.
Explanation:
That's the most straight forward explanation I could come up with
Who has the more valued Exports?
South Africa or Egypt?
pls help ill mark brainliest! star and heart :)
Answer:
Egypt
Explanation:
Hi again
A rock's mass is a:
A. all of the above
B. chemical property
C. physical property
D. constant property
Answer:
all of the above
Explanation:
now I will bless you with this-
You can use solid, wedged, and dashed lines to better represent the 3D structure of molecules. The solid lines represent bonds in the plane of the paper, wedged lines represent a bond coming out of the plane, and the dashed line represents a bond going back behind the plane of the paper. Draw a representation of methane that better depicts its 3D structure.
Answer:
See explanation and image attached
Explanation:
Often times, there is a need for a three dimensional representation of a molecule on paper. These three dimensional representations give us an idea of what the molecule really looks like if we were to be looking at it physically.
In order to make a three dimensional representation, we use wedged and dashed bonds. The wedged bonds are coming out of the plane of the paper towards you while the dashed bonds are going into the plane of the paper away from you.
In the image attached, you will find the three dimensional representation of the methane molecule.
The best known Lepton is the _________________.
a
electron
b
boson
c
fermion
d
hadron
e
neutron
f
proton
Answer:
Electron (e-)
Explanation:
An electron is just one of the fundamental particles
Answer:heyyyy
Explanation:
The 10x SDS gel electrophoresis buffer contains 250mM Tris HCl, 1.92M Glycine, and 1% (w/v) SDS. Buffers are always used at 1x concentration in the lab (unless specified otherwise in the protocol), so you will have to dilute the 10x buffer to 1x before use. What is the concentration of Tris and SDS in the 1x buffer
Answer:
25 mM Tris HCl and 0.1% w/v SDS
Explanation:
A 10X solution is ten times more concentrated than a 1X solution. The stock solution is generally more concentrated (10X) and for its use, a dilution is required. Thus, to prepare a buffer 1X from a 10X buffer, you have to perform a dilution in a factor of 10 (1 volume of 10X solution is taken and mixed with 9 volumes of water). In consequence, all the concentrations of the components are diluted 10 times. To calculate the final concentration of each component in the 1X solution, we simply divide the concentration into 10:
(250 mM Tris HCl)/10 = 25 mM Tris HCl
(1.92 M glycine)/10 = 0.192 M glycine
(1% w/v SDS)/10 = 0.1% w/v SDS
Therefore the final concentrations of Tris and SDS are 25 mM and 0.1% w/v, respectively.
PLS HELLPPPP
Which of the following objects would have the greatest gravitational attraction between them if they were set 3.0 km apart?
A .20kg object and a 200kg object
A 10kg object and a 100kg object
A 30kg object and a 200,000kg object
A 400,000 kg object and a 100,000,000kg object
Answer:
A 400,000 kg object and a 100,000,000kg object
Explanation:
The objects with the most mass between them will have the greatest gravitational attraction.
This is why the last option is the right choice.
The reason for this is based on the Newton's law of universal gravitation which states that:
"the gravitational force of attraction between two bodies is directly proportional to the product of their masses and inversely proportional to the square of the distance between them".
So, the more the mass, the greater the gravitational attraction between two bodies.
Temperature can weather rocks because A heat can cause minerals to oxidize B. most rocks do not absorb heat evenly C. water contracts when it freezes D. rocks usually melt in the hot sun
Answer:
b
Explanation:
it is not c because water expands when it freezes.
PLEASE HELP BRAINLIEST AND 15 points.
1. Which substance is nonvolatile ?
(1.5 Points)
Substance B, boiling point of 105 °C
Substance C, boiling point of 25 °C
Substance A, boiling point of 75 °C
Substance d, boiling point of 45 °C
Answer:
Substance B, boiling point of 105 °C
Explanation:
Non volatile substances have high boiling points
Which of the following has the largest atomic radius?
Answer:
b
Explanation:
A state of matter where the particles that make up a substance start to break apart
Answer:
Liquid
Explanation:
A force of 7 N acts on an object. The displacement is, say 8 m, in the direction of the force. Let us take it that the force acts on the object through the displacement. What is the work done in this case?
Answer:
56 J
Explanation:
Step 1: Given data
Force applied on the object (F): 7 NDisplacement of the object (d): 8 mStep 2: Calculate the work (w) done on the object
We can find the work done on the object using the following expression.
w = F × d × cosθ
where
θ is the angle between F and d
Since F and d occur in the same direction, θ = 0° and cosθ = 1. Then,
w = F × d × 1
w = F × d
w = 7 N × 8 m = 56 J
When 70.4 g of benzamide (C7H7NO) are dissolved in 850. g of a certain mystery liquid X, the freezing point of the solution is 2.7 C lower than the freezing point of pure X. On the other hand, when 70.4 g of ammonium chloride (NH CI) are dissolved in the same mass of X, the freezing point of the solution is 9.9 °C lower than the freezing point of pure X.
Required:
Calculate the van't Hoff factor for ammonium chloride in X.
Answer:
1.62
Explanation:
From the given information:
number of moles of benzamide [tex]=\dfrac{70.4 \ g}{121.14 \ g/mol}[/tex]
= 0.58 mole
The molality = [tex]\dfrac{mass \ of \ solute (i.e. \ benzamide )}{mass \ of \ solvent }[/tex]
[tex]= \dfrac{0.58 }{0.85 }[/tex]
= 0.6837
Using the formula:
[tex]\mathbf {dT = l \times k_f \times m}[/tex]
where;
dT = freezing point = 27
l = Van't Hoff factor = 1
kf = freezing constant of the solvent
∴
2.7 °C = 1 × kf × 0.6837 m
kf = 2.7 °C/ 0.6837m
kf = 3.949 °C/m
number of moles of NH4Cl = [tex]\dfrac{70.4 \ g}{53.491 \ g /mol}[/tex]
= 1.316 mol
The molality = [tex]\dfrac{1.316 \ mol}{0.85 \ kg}[/tex]
= 1.5484
Thus;
the above kf value is used in determining the Van't Hoff factor for NH4Cl
i.e.
9.9 = l × 3.949 × 1.5484 m
[tex]l = \dfrac{9.9}{3.949 \times 1.5484 \ m}[/tex]
l = 1.62
Were any of your substances difficult to identify as polar, nonpolar, or ionic? Explain.
Answer:
See explanation
Explanation:
A substance is classified as polar, nonpolar or ionic based on its behavior.
For the substances identified, there was no difficult in identifying each as polar, nonpolar, or ionic because since it was quite to easy identify where each belongs by looking out for whether it mixes or dissolves in our experiment.
Every substance in the experiment either mixed or dissolved during the experiment.
If it takes 38.70cm of 1.90M NaOH to neutralize 10.30cm of H2SO4 in a battery, what is the molarity of H2SO4?
Answer:
The molarity of the acid, H₂SO₄ is 3.57 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H₂SO₄ + 2NaOH —> Na₂SO₄ + 2H₂O
From the balanced equation above,
Mole ratio of the acid, H₂SO₄ (nₐ) = 1
Mole ratio of the base, NaOH (n₆) = 2
Finally, we shall determine the molarity of the acid, H₂SO₄. This can be obtained as follow:
Volume of base, NaOH (V₆) = 38.70 cm³
Molarity of base, NaOH (M₆) = 1.90M
Volume of acid, H₂SO₄ (Vₐ) = 10.30 cm³
Molarity of acid, H₂SO₄ (Mₐ) =?
MₐVₐ / M₆V₆ = nₐ/n₆
Mₐ × 10.3 / 1.9 × 38.70 = 1/2
Mₐ × 10.3 / 73.53 = 1/2
Cross multiply
Mₐ × 10.3 × 2 = 73.53 × 1
Mₐ × 20.6 = 73.53
Divide both side by 20.6
Mₐ = 73.53 / 20.6
Mₐ = 3.57 M
Thus, the molarity of the acid, H₂SO₄ is 3.57 M