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 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.
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
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.
Why do organisms eat food? Be sure to explain your answer.
Answer:
Organisms need to take food to get energy and perform life processes. A living organism undergoes many life processes like nutrition, respiration, digestion, transportation, excretion, circulation of blood, and reproduction. To perform all these life processes the organism needs energy and nutrients.
Explanation:
nnastarannnn his idea
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
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
A copper wire is 44.85 cm long and weighs 1.521 g. The density of copper is 8.933 g/cm3.
What is the radius of the wire in millimeters?
What is the diameter of the wire?
Answer:
i am so sorry
Explanation:
The density of copper is If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.
How can we calculate the mass from density and volume?Density is defined as the mass per unit volume it means that mass present in 1 meter cube is called density. The S.I unit of density is kg/m^3 and in C.G.S it is gram/cm^3
So, In above question can understand that density, mass, and volume all are convert to each other it means that if we know any two variable then third one will be calculated easily.
Mathematically,
Formula for density will be as mentioned below:-
Density = Mass/Volume.
From above formula we can calculate mass which is as follows:-
Mass = Volume × Density.
S.I unit of mass is kilograms and C.G.S unit is gram.
So In above question
Density = 8.933 gram/cm^3
Volume = 12.993 cm^3
So from above formula
Mass = Density × volume
= 10.49 × 12.993
= 136.29 gram
= 0.13629 kilogram
So Mass is equal to 136.29 gram or 0.136 kilograms.
Therefore,The density of copper is If a sample 8.933 g/cm3. If copper has a volume of 12.993 cm^3. Then the mass will be 136.29 gram.
Learn more about density here:
https://brainly.com/question/15164682
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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
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:
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
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 %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.
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°CWhat type of rock is limestone? Describe how a limestone rock is likely to change over a long period of time. Pls answer I will mark brainiest.
What type of rock is limestone? Describe how a limestone rock is likely to change over a long period of time. Pls answer I will mark brainiest.
Answer:Sedimentary Rock Limestone being a sedimentary rock would be converted to marble, a metamorphic rock if subjected to metamorphic conditions over an extensive period of time. Over a long period of time, we would take a look at the rock "limestone" through the rock cycle.#CARRYONLEARNING #STUDYWELL100 POINTS FOR BEST ANSWER! What is the difference between LDOF and SDOF
An SDOF system is one whose motion is governed by a single, second-order differential equation. Only two variables, position and velocity are needed to describe the trajectory of the system. Many structures can be idealized as single degree-of-freedom systems.
The LDAP Data Interchange Format is a standard plain text data interchange format for representing LDAP directory content and update requests. LDIF conveys directory content as a set of records, one record for each object.
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
Ammonium phosphate is an important ingredient in many solid fertilizers. it can be made by reacting aqueous phosphoric acid with liquid ammonia. calculate the moles of ammonium phosphate produced by the reaction of 0.085 mol of ammonia. be sure your answer has a unit symbol, if necessary, and round it to the correct number of significant digits.
Answer:
0.028 mole of ammonium phosphate, (NH₄)₃PO₄.
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
H₃PO₄ + 3NH₃ —> (NH₄)₃PO₄
From the balanced equation above,
3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.
Finally, we shall determine the number of mole of (NH₄)₃PO₄ produced by the reaction of 0.085 mole of ammonia, NH₃. This can be obtained as follow:
From the balanced equation above,
3 moles of NH₃ reacted to produce 1 mole of (NH₄)₃PO₄.
Therefore, 0.085 mole of NH₃ will react to produce = (0.085 × 1)/3 = 0.028 mole of (NH₄)₃PO₄.
Thus, 0.028 mole of ammonium phosphate, (NH₄)₃PO₄ were obtained from the reaction.
To solve the ultraviolet catastrophe, Planck applied quantization to: Select the correct answer below:
A. vibrational energies of atoms
B. orbital energies of electrons
C. kinetic energies of photons
D. temperature of the system
Answer:
Vibrational energies of atoms
Explanation:
Planck applied quantization to Vibrational energies of atoms because in Black body spectrum prediction a blackbody at equilibrium is expected to radiate energies at various Frequencies ( i.e. increase in radiated energy ∝ increase in frequency ) but towards the ultraviolet region of the spectrum the energy radiated begins to drop as frequency increases. The phenomenon of drop in energy with increase in frequency is termed Ultraviolet catastrophe. hence to solve this phenomenon Planck applied quantization to Vibrational energies of atoms
A certain substance X condenses at a temperature of 123.3°C . But if a 650. g sample of X's prepared with 24.6 g of urea ((NH2)2 CO) dissolved in it, the sample is found to have a condensation point of 124.3°C instead. Calculate the molal boiling point elevation constant Kb of X.
Answer:
1.6 °C.kg/mol
Explanation:
Step 1: Calculate the molality of urea
We will use the following expression.
m = mass(urea) / molar mass(urea) × kg solvent
m = 24.6 g / 60.06 g/mol × 0.650 kg
m = 0.630 mol/kg
Step 2: Calculate the boiling point elevation of X
The boiling point elevation is a colligative property that can be calculated using the following expression.
ΔTb = 124.3 °C - 123.3 °C = 1.0 °C
Step 3: Calculate the boiling point elevation constant
We will use the following expression.
ΔTb = Kb × m
Kb = ΔTb/m
Kb = 1.0 °C/(0.630 mol/kg) = 1.6 °C.kg/mol
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
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.
You'll be given 100 points if you answer this question!!!!!!!!!!!!
3.
What do we call materials
that let heat pass through
them easily?
Thermal conductors
Thermal insulators
Transparent
4.
Which of these is a good
thermal conductor?
Plastic
Wood
Steel
5.
Which of these is a good
thermal insulator?
Steel
Iron
Polystyrene
6.
To save on heating bills, do
you think the roof of a
building should be lined with
a thermal conductor
a thermal insulator
nothing
7.
How does heat travel?
From cold things to hotter things
From hot things to colder things
Between things of the same temperature
Answer:conducts ,steel, polystyrene, thermal insulation
Explanation:
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.
Which of the following has the largest atomic radius?
Answer:
b
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
Which factors directly affect the magnetic force produced by an electromagnet?
O number of turns in the wire, amount of current
O amount of current, type of force
O length of core, number of turns in the wire
O amount of current, length of core
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
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.
A state of matter where the particles that make up a substance start to break apart
Answer:
Liquid
Explanation:
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:
