Answer:
1.6734 g\ml..hope it helps
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.
Which of the following is a list of the minimum amount of data needed for determining the molar enthalpy of solution of KCl(s) in pure H2O(1) ? (Assume that the KCl(aq) has the same specific heat capacity as pure water and that the initial temperatures of the KCl(s) and the water are the same.)
(A) Mass of KCl(s), initial temperature of the water, and final temperature of the solution
(B) Mass of H20, initial temperature of the water, and final temperature of the solution
(C) Mass of KCl(s), mass of H20, initial temperature of the water, and final temperature of the solution
(D) Mass of KCl(s), mass of H20, initial temperature of the water, final temperature of the solution, and atmospheric pressure
Answer:
(C) Mass of KCl(s), mass of H20, initial temperature of the water, and final temperature of the solution
Explanation:
molar enthalpy of solution of KCl(s) is heat evolved or absorbed when one mole of KCl is dissolved in water to make pure solution . The heat evolved or absorbed can be calculated by the following relation.
Q = msΔt where m is mass of solution or water , s is specific heat and Δt is change in temperature of water .
So data required is mass of water or solution , initial and final temperature of solution , specific heat of water is known .
Now to know molar heat , we require mass of solute or KCl dissolved to know heat heat absorbed or evolved by dissolution of one mole of solute .
The correct option is option C.
To determine the molar enthalpy of the solution of [tex]Kcl(s)[/tex] is pure [tex]H_2O(l)[/tex]
We need to know that the,
grams of [tex]Kcl(s)[/tex] grams of [tex]H_2O[/tex] Initial temperature of [tex]H_2O[/tex] The final temperature of the solution.Learn More:https://brainly.com/question/25758173
The camel stores the fat tristearin (C57H110O6) in its hump. As well as being a source of energy, the fat is also a source of water because, when it is used, the reaction 2 C57H110O6(g) + 163 O2(g) 114 CO2(g) + 110 H2O(ℓ) takes place. What mass of water is available from 1.6 pound of this fat? Answer in units of g.
Answer:
8.1 × 10² g
Explanation:
Step 1: Write the balanced equation
2 C₅₇H₁₁₀O₆ + 163 O₂ ⇒ 114 CO₂ + 110 H₂O
Step 2: Convert 1.6 lb of C₅₇H₁₁₀O₆ to g
We will use the conversion factor 1 lb = 453.592 g.
1.6 lb × 453.592 g/1 lb = 7.3 × 10² g
Step 3: Calculate the moles corresponding to 7.3 × 10² g of C₅₇H₁₁₀O₆
The molar mass of C₅₇H₁₁₀O₆ is 890.83 g/mol.
7.3 × 10² g × 1 mol/890.83 g = 0.82 mol
Step 4: Calculate the moles of water produced from 0.82 moles of C₅₇H₁₁₀O₆
The molar ratio of C₅₇H₁₁₀O₆ to H₂O is 2:110. The moles of H₂O produced are 110/2 × 0.82 mol = 45 mol
Step 5: Calculate the mass corresponding to 45 moles of H₂O
The molar mass of H₂O is 18.02 g/mol.
45 mol × 18.02 g/mol = 8.1 × 10² g
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:
GRADE 5 SCIENCE MYA-2020-2021
Testosters are testing the choict of light on a radiometer Team 1 finds that blue light makes the radiometer spin slower when a blue light is 35 centimeters (cm) away. To validate Team 1's test results, how must
Text with and that is 20 cm away
Test what that is 45 cm away
Test with a green light that is 40 cm away
Test with the light that is 35 cm away
Answer:
Test it with a blue light that is 45 cm away.
Explanation:
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
identified the nucleus that is found in an item that has a stable valance electron configuration
Answer:
Nucleus 3 i believe
Which statement is always true about conversation of matter?
The mass of a system does not change during a chemical reaction
If a solid forms the mass of a system increases
If a gas forms the mass of a system decreases
The mass of a system changes when a substance changes from liquid to gas, but it does not change in a chemical reaction
Answer:
The mass of a system does not change during a chemical reaction
Explanation:
Correct Answers
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.
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
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
100 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.
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.
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)"
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.
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
Which of the following has the largest atomic radius?
Answer:
b
Explanation:
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 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 %Bond length is the distance between the centers of two bonded atoms. On the potential energy curve, the bond length is the internuclear distance between the two atoms when the potential energy of the system reaches its lowest value. Consider that the atomic radius (sometimes called the covalent or bonding atomic radius) of an element is defined as one-half the distance between the bonded atoms in a homonuclear diatomic molecule. Actual bond lengths in molecules are determined experimentally by such methods as X-ray diffraction and microwave spectroscopy. However, these atomic radii values can be used to give an estimate of the upper limit of bond length in other (heteronuclear) molecules. Given that the atomic radii of H and Br are 37.0 pm and 115 pm , respectively, predict the upper limit of the bond length of the HBr molecule.
Answer:
152 pm
Explanation:
According to the question, we can estimate the bond length from the given values of the atomic radii. This now is the upper limit of the bond length for the molecule.
Since we have that;
Atomic radius of H= 37.0 pm
Atomic radius of Br = 115.0 pm
Bond length = Atomic radius of H + Atomic radius of Br
Bond length = 37.0 pm + 115.0 pm
Bond length = 152 pm
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
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:
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.
Learn more in:
https://brainly.com/question/10281181
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 statement correctly describes ionic bonds? Multiple Choice An ionic bond only forms between two atoms of the same element. Ionic bonds usually form between electrically neutral, stable atoms. An ionic bond is the electrostatic force that holds ions together when they form bonds. All of the answer choices are correct.
Answer:
An ionic bond is the electrostatic force that holds ions together when they form bonds
Explanation:
An ionic bond is formed when a metal looses electron(s) to a non metal leading to the formation of a positive ion and a negative ion.
An ionic compound is actually an ion pair, the ions are held together by strong electrostatic forces.
This strong electrostatic force that holds the ion pair together in ionic compounds is what we commonly call the IONIC BOND.
Answer:
An ionic bond is the electrostatic force that holds ions together when they form bonds
Explanation:
I took this test and it was the correct answer :)
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
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 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
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
A state of matter where the particles that make up a substance start to break apart
Answer:
Liquid
Explanation:
