Answer:
:0
Explanation:
One second after the Big Bang, the universe was filled with neutrons, protons, electrons, anti-electrons, photons and neutrinos.Jun 17, 2017
What is the molality of a solution made by dissolving 3.71 g of sodium chloride in 0.535 L of water?
Answer:
Molality of the solution is 0.119 mol/kg
Explanation:
Molality is the type of concentration that indicates the moles of solute in 1 kg of solvent.
As we assume water's density as 1 g/mL, we need to calculate the mass of water (our solvent).
We convert 0.535 L to mL → 0.535 L = 535 mL
By the way, water's mass is 535 g.
We convert the mass from g to kg → 535 g = 0.535kg
We need to calculate the moles of solute, NaCl.
3.71 g . 1mol / 58.45 g = 0.0635 mol
Molality = mol/kg → 0.0635 mol / 0.535kg = 0.119 m
A 150-lb patient is prescribed acetaminophen at 7.34 mg/kg. If acetaminophen is available on hand as a 0.125 mg/ml syrup, how many mililiters will the nurse administer?
Answer:
The nurse should administer 3995.2 millilitres of syrup.
Explanation:
The conversion factor of pound weight to kilogram is; 1 lb = 0.453592 kg
The body weight of the patient in Kg = 150 * 0.453592 = 68.04 kg
A prescription of 7.34 mg/kg acetaminophen means that he should receive;
7.34 mg * 68.04 = 499.4 mg of acetaminophen
Amount in grams of acetaminophen per millilitre of syrup = 0.125 mg
Number of millilitres of syrup required = 499.4 mg / 0.125 mg/mL = 3995.2 mL
Therefore, the nurse should administer 3995.2 millilitres of syrup.
If you burn 57.9 g of hydrogen and produce 517 g of water, how much oxygen reacted?
In order to make water (H2O) out of hydrogen (H2), you also need OXYGEN (O2) gas. So, first write a correctly balanced equation for this reaction.
2H2(g) + O2(g) ==> 2H2O
Now, convert 59.5 g of H2 to moles, then figure out moles of H2O and then moles of O2 used to do this.
moles H2 = 59.5 g H2 x 1 mole/2 g = 29.8 moles H2
moles H2O formed = 531 g H2O x 1 mole/18 g = 29.5 moles H2O
So, the mole ratio of H2 to H2O is 1:1 meaning that the moles of O2 used will be 1/2 that amount. This is the case because from the balanced equation you see that 1 O2 reacts with 2 H2 and produces 2 H2O.
Amount of O2 used = 29.8/2 = 14.9 moles
If the atomic number of an element is 6 and its mass number is 14, how many neutrons are contained in the nucleus?
Answer:
8
Explanation:
because 14 - 6 is 8
What will be the amount of sugar in milligrams if the size of the milk chocolate bar is reduced from 14.630 g to 3.000 g ?
Answer:
Explanation:
The quantity of sugar in the bar of milky chocolate of 45 g is 25 g of sugar
u can use this information to calculate the amount of the sugar in any amount .
mass of sugar in 14.630 g →
chocolate mass sugar mass
45 g 25 g
14.630 x
X= mass of sugar = 8.13 g
now for 3 gram of chocolate :
45 g 25 g
3.000 x
X = 1.667 grams of sugar
Assume that each large number is a centimeter. How long is this pencil? Only part of the pencil is shown. Pick the best estimate.
A) 8.25 cm
B) 8.3 cm
C) 83 cm
D) 8.0 cm
From the figure we can notice that the tip is ended surely before 9 cm .
Also , the tip crossed two cuts after 8 .
Therefore , it is greater than 8.2 .
Now , if we see that the tip end between 2 and 3 .
Therefore , the best estimate is 8.25 cm .
Hence , this is the required solution .
A 1.00 kg sample of water at 9.00°C is in a calorimeter. You drop a piece of steel with a mass of 0.370 kg at 210°C into it. After the sizzling subsides, what is the final equilibrium temperature (in °C)? (Make the reasonable assumptions that any steam produced condenses into liquid water during the process of equilibration and that the evaporation and condensation don't affect the outcome.)
Answer:
The final temperature of the water-steel system is 16.853 ºC.
Explanation:
We consider the system of water sample and the piece of steel as control mass, which is supposed to be an isolated system, that is, a system with no mass and energy transfer with surroundings. As water has more mass and a higher specific heat that piece of steel, it is very unlikely that evaporation and condensation would affect the outcome.
The piece of steel is cooled down while water is heated up, until thermal equilibium is reached. By First Law of Thermodynamics, we must observe that:
[tex]Q_{water}-Q_{steel} = 0[/tex]
[tex]Q_{water} = Q_{steel}[/tex]
Where:
[tex]Q_{water}[/tex] - Heat received by the water sample, measured in joules.
[tex]Q_{steel}[/tex] - Heat released by the piece of steel, measured in joules.
Now, we expand each term by definition of sensible heat:
[tex]m_{w}\cdot c_{w}\cdot (T-T_{w,o})=m_{s}\cdot c_{s}\cdot (T_{s,o}-T)[/tex]
Where:
[tex]m_{w}[/tex], [tex]m_{s}[/tex] - Masses of the water sample and the piece of steel, measured in kilograms.
[tex]c_{w}[/tex], [tex]c_{s}[/tex] - Specific heat of water and steel, measured in joules per kilogram-Celsius.
[tex]T_{w,o}[/tex], [tex]T_{s,o}[/tex] - Initial temperatures of the water sample and the piece of steel, measured in Celsius.
[tex]T[/tex] - Final temperature of the sample-piece system, measured in Celsius.
The final temperature is cleared:
[tex](m_{w}\cdot c_{w}+m_{s}\cdot c_{s})\cdot T = m_{w}\cdot c_{w}\cdot T_{w,o}+m_{s}\cdot c_{s}\cdot T_{s,o}[/tex]
[tex]T = \frac{m_{w}\cdot c_{w}\cdot T_{w,o}+m_{s}\cdot c_{s}\cdot T_{s,o}}{m_{w}\cdot c_{w}+m_{s}\cdot c_{s}}[/tex]
If we know that [tex]m_{w} = 1\,kg[/tex], [tex]m_{s} = 0.370\,kg[/tex], [tex]c_{w} = 4186\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]c_{s} = 460\,\frac{J}{kg\cdot ^{\circ}C}[/tex], [tex]T_{w,o} = 9\,^{\circ}C[/tex] and [tex]T_{s,o} = 210\,^{\circ}C[/tex], the final temperature of the system is:
[tex]T = \frac{(1\,kg)\cdot \left(4186\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (9\,^{\circ}C)+(0.370\,kg)\cdot \left(460\,\frac{J}{kg\cdot ^{\circ}C} \right)\cdot (210\,^{\circ}C)}{(1\,kg)\cdot \left(4186\,\frac{J}{kg\cdot ^{\circ}C} \right)+(0.370\,kg)\cdot \left(460\,\frac{J}{kg\cdot ^{\circ}C} \right)}[/tex]
[tex]T = 16.853\,^{\circ}C[/tex]
The final temperature of the water-steel system is 16.853 ºC.
The element uranium ( U ) has three naturally occuring isotopes, U234 , U235 , and U238 . U234 has an isotopic mass of 234.04 u and a relative abundance of 0.0054%. U235 has an isotopic mass of 235.04 u and a relative abundance of 0.7204%. U238 has an isotopic mass of 238.051 u and a relative abundance of 99.2742%. Calculate the average atomic mass of uranium.
Answer:
[tex]m_U=238.03u[/tex]
Explanation:
Hello,
In this case, since the average atomic mass for the given element is computed by taking into account the mass of each isotope and their abundance, we proceed as follows:
[tex]m_U=234.04u*0.0054\%+235.04u*0.7204\%+238.051u*99.2742\%\\\\m_U=0.01264+1.69323+236.3232\\\\m_U=238.03u[/tex]
Best regards.
which element is less electronegative than silicon (Si)
Answer:
caesium
Explanation:
because it's lesssssssss
Atomic weight is the ?
A. average number of neutrons in an element's isotopes
B. combined masses of an element's isotopes
C. weighted average of an element's isotopes
Answer:
c
Explanation:
It is the weighted average of the isotopes. For example chlorine has two common masses for 2 isotopes.
The lighter one (and most common) is 34.96885
The heavier one is 36.96590
Now if you take the average of these two, you get 70.92/2 = 35.46 which is not the right answer. The right answer must take into account the abundance of the two isotopes.
36.590 * 0.2447 = 8.9536
34.96885*.7553=26.4120
The total is the periodic table mass which is 35.36557
The difference may not appear to be important, but an element has a lot of isotopes with quite a difference in them, the difference might be important.
Glass, rubber, and plastic are all forms of A. allotropic solids C. covalent network solid B. amorphous solids X D. crystalline solids Elements, such as sulfur, carbon, and phosphorus, are more than one structural form in the solid state. A. allotropic C. crystalline B. amorphous D. orthorhombic RECI CORRECT CHECK
Answer:
B. amorphous
Explanation:
Examples of amorphous solids include glass, rubber, and plastics.
Draw the product formed when the Lewis acid (CH3CH2)3C reacts with the Lewis base (CH3)2NH.
Answer:
Explanation:
When the Lewis base (CH3)2NH reacts with Lewis acid Lewis acid (CH3CH2)3C⁺ which is also a carbocation , a new bond is formed as follows by the donation of a loan pair of electrons by the nitrogen atom of
(CH3)2NH . Here (CH3)2NH donates electrons so it acts as base and the second group accepts electrons so it is acid .
THe structure of the product formed is shown in the file attached .
What is the closest to potassium
Calculate the lattice energy for LiF(s) given the following: sublimation energy for Li(s) +166 kJ/mol bond dissociation energy to produce F(g) +77 kJ/mol first ionization energy (IE1) of Li(g) +520. kJ/mol electron affinity (EA) of F(g) -328 kJ/mol enthalpy of formation of LiF(s) -612 kJ/mol
Answer:
The lattice energy for LiF(s) is -1047 kJ/mol
Explanation:
Given;
Sublimation energy, ΔHs = 166 kJ/mol
bond dissociation energy, BE = +77 kJ/mol
first ionization energy, IE₁ = +520 kJ/mol
electron affinity, EA = -328 kJ/mol
enthalpy of formation, ΔHf = -612 kJ/mol
[tex]L_iF_{(s)}[/tex] ⇄ [tex]Li_{(g)}^+\ \ + \ \ F^-_{(g)}[/tex]
Apply the following equation to calculate the lattice energy for, LiF(s),
Let the lattice energy = U
ΔHf = ΔHs + BE + IE₁ + EA + U
-612 = 166 + 77 + 520 -328 + U
-612 = 435 + U
U = -612 - 435
U = -1047 kJ/mol
Therefore, the lattice energy for LiF(s) is -1047 kJ/mol
The lattice energy of LiF is -1047 KJ/mol.
The lattice energy is the energy is the energy evolved when one mole of the ionic solid is formed from its constituents. The ionic lattice energy depends on the size of the ions.
We have the following information from the question;
Enthalpy of formation of LiF (ΔHf ) = -612 kJ/mol
Heat of sublimation of Li (ΔHs) = +166 kJ/mol
Bond energy of F2 (BE) = +77 kJ/mol
Ionization energy of Li (IE₁) = +520. kJ/mol
Electron affinity of F(g) (EA) = -328 kJ/mol
Lattice energy (U) = ?
The lattice energy can be obtained using the Hess law of constant heat summation as follows;
ΔHf = ΔHs + BE + IE₁ + EA + U
U = ΔHf - [ΔHs + BE + IE₁ + EA ]
U = -612 kJ/mol - [(+166 kJ/mol ) + ( +77 kJ/mol) + (+520. kJ/mol) + ( -328 kJ/mol)]
U =-612 kJ/mol - 435 KJ/mol
U = -1047 KJ/mol
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What element is CU?plz helpppp
What is 0.75140000 in scientific notation
Answer:
Sig Figs
8
Decimals
8
Scientific Notation
7.5140000 × 10-1
Explanation:
In order for convection to transfer heat, particles need to
absorb solar and fossil energy
O circulate and move within a liquid or gas
O make contact with the heat source
transmit electromagnetic waves
Answer:
The answer is B "circulate and move within a liquid or gas"
Which of the following correctly describes what happens to the kinetic energy of water when it changes from steam to a liquid? The kinetic energy of the molecules increases. The kinetic energy of the molecules decreases. The kinetic energy of the molecules increases then decreases. There is no change in the kinetic energy of the molecules
what is the answer to this^
Your answer would be D.
Carbon and oxygen can only combine to form one compound. Select one aFalse b. True
Answer:
False
Explanation:
Carbon and Oxygen can for Carbon Monoxide (CO), Carbon Dioxide (CO2), Carbon Trioxide (CO3), etc.
Which of the following questions can be answered by science? (2 points) What makes a song sound beautiful? What is the meaning of life? What makes a painting beautiful? What are the effects of low pH in soil?
Answer: The answer is "What are the effect of low pH in soil"
Explanation: This is because this can be tested and because it is not a opinion or a moral value. Thus this question can be tested with the scientific method.
The question that can be answered by science is "What are the effects of low pH in soil". Thus, the correct option for this question is D.
What is Science?Science may be defined as a branch of scientific study that involves the application of knowledge and understanding of the natural and social world following a systematic methodology based on evidence.
It can broadly be classified into three categories such as Physics, Chemistry, and biology. Each sub-classification illustrates its own field of detailed study.
Science always deals with the concept of nature as well as natural phenomena. So, among the given options, the soil is an abiotic component of nature.
The effects of low pH in the soil depend on various factors like the complexity of organisms living on a particular area, resources, pollution level, etc.
Therefore, the question that can be answered by science is "What are the effects of low pH in soil". Thus, the correct option for this question is D.
To learn more about Soil pH, refer to the link:
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For each of the described sets of data, choose the graph that best displays the data.
Changes in the temperature of an ice cube taken every minute for 15 minutes
a.) line graph
b.) scatter plot
c.) bar graph
d.) histogram
The changes in the temperature of an ice cube taken every minute for 15 minutes can be easily evidenced by a line graph (Option A).
What is a line graph?A line graph is a diagram that represents the changes in one variable through a horizontal axis and one vertical axis.
A line graph is very useful to show how a variable may change along a given period of time.
In conclusion, the changes in the temperature can be evidenced by a line graph (Option A).
Learn more about line graphs here:
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Answer:
A) line graph
Explanation:
edge 2023
You wish to prepare 250.0250.0 mL of a 400.0400.0 ppm w/v Fe2+Fe2+ ( MW=55.845 g/molMW=55.845 g/mol ) solution. How many grams of ferrous ammonium sulfate hexahydrate (Fe(NH4)2(SO4)2⋅6H2O(Fe(NH4)2(SO4)2⋅6H2O , MW=392.14 g/molMW=392.14 g/mol ) are needed to prepare this solution? Assume the final solution has a density of 1.00 g/mL.
Answer:
You need 0.702g of ferrous ammonium sulfate hexahydrate to prepare the desired solution.
Explanation:
First, you want to prepare 250.0mL of a 400.0ppm of Fe²⁺ (That is mg/L, w/v):
0.250L * (400mg / L) = 100mg Fe²⁺ = 0.1g Fe²⁺
Molar mass of Fe is 55.845g. moles are:
0.1g Fe²⁺ * (1mol / 55.845g) =
1.79x10⁻³ moles Fe²⁺The Fe²⁺ comes from ferrous ammonium sulfate hexahydrate, as 1 mole of this salt contains 1 mole of Fe²⁺, moles of the salt you need are:
1.79x10⁻³ moles Fe(NH₄)₂(SO₄)₂.6H₂O.
To convert these moles to grams you must use molar weight, MW, thus:
1.79x10⁻³ moles Fe(NH₄)₂(SO₄)₂.6H₂O * (392.14g / 1mol) =
You need 0.702g of ferrous ammonium sulfate hexahydrate to prepare the desired solution.. Monthly measurements of atmospheric CO2 concentration at Mauna Loa began in March 1958. The average CO2 concentration for that month was 315.71 ppm. In 2020, the March monthly average value was 414.51 ppm. Calculate the total increase in March concentration (in ppm) from 1958-2020 (62 years). Also calculate the average increase per year.
Answer:
[tex]Increase=98.8ppm[/tex]
[tex]Average\ increase/year=1.594\frac{ppm}{year}[/tex]
Explanation:
Hello,
In this case, since the nowadays concentration of CO2 is 414.51 ppm and the concentration in 1958 was 315.71 ppm, the total increase is computed via the difference between them:
[tex]Increase=414.51ppm-315.71ppm\\\\Increase=98.8ppm[/tex]
Moreover, the average increase per year is computed considering that from 1958 to 2020, 62 years have passed, therefore, such average is:
[tex]Average\ increase/year=\frac{98.8ppm}{62 years} \\\\Average\ increase/year=1.594\frac{ppm}{year}[/tex]
Regards.
A. The total increase in March concentration (in ppm) from 1958 to 2020 is 98.8 ppm
B. The average increase per year is 1.59 ppm / year
A. How to determine the increase Concentration in March 1958 = 315.71 ppmConcentration in March 2020 = 414.51 ppmIncrease =?Increase = (Concentration in March 2020) – (Concentration in March 1958)
Increase = 414.51 – 315.71
Increase = 98.8 ppm
B. How to determine increase per year Increase = 98.8 ppmTotal year = 2020 – 1958 = 62Increase per year =?Increase per year = Increase / Total year
Increase per year = 98.8 / 62
Increase per year = 1.59 ppm / year
Learn more about percentage increase:
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What is the oxidation number for arsenic in the product of the following reaction?
As + Cl2 → AsCl3
Answer:
+3
Explanation:
The oxidation number of a specie is the charge that it appears to have as determined by some arbitrary rules.
If we look at the reaction, we will notice that arsenic is more electro positive than chlorine so it is likely to function as the reducing agent in the reaction, loosing three electrons to have an oxidation number of +3 in the product.
What is the percent composition of Sb2F3.What is the percent composition of F in this molecule? Round the answer to five significant figures.
Answer:
[tex]\%F=18.967\%[/tex]
Explanation:
Hello,
In this case, a percent composition is computed by considering the atomic mass of each element in the compound as well as the number of atoms and the molar mass of the compound. Thus, Sb2F3 has a molar mass of 300.52 g/mol, antimony has an atomic mass of 121.76 g/mol and fluorine 19.0 g/mol, therefore, the percent composition of fluorine which has three atoms with five significant figures is:
[tex]\% F=\frac{3*19.0g/mol}{300.52g/mol}*100\%\\ \\\%F=18.967\%[/tex]
Best regards.
1. Working in the laboratory, a student find the density of a piece of pure aluminum to be 2.85
g'om? The accepted value for the density of aluminum is 2.699 g/cm? What is the student's
percent error?
Answer:
5.59 %
Explanation:
From the question given above, the following data were obtained:
Observed value of density = 2.85 g/cm³
True value of density = 2.699 g/cm³
Percentage error =.?
The percentage error of the student can be obtained as follow:
Percentage error = |Observed value – True value|/True value × 100
Percentage error = |2.85 – 2.699|/2.699
Percentage error = 0.151/2.699 × 100
Percentage error = 5.59 %
Therefore, the percentage error of the student is 5.59 %.
Carbohydrates are made up of carbon, hydrogen, and __________.
Which term best completes the sentence?
oxygen
copper
helium
potassium
Answer:
oxygen
Explanation:
Which of the following is a positively charged subatomic particle?
Electron
Neutron
Nucleus
Proton
A piece of brass is found to have a mass of 24.32 g. When placed in a graduated cyclinder with an initial reading of 5.60 mL the water level rises to 13.50 mL. What is the density of the piece of brass? Record your answer using sig figs and the correct unit. (Example: 2.3 g/mL)
Answer:
[tex]\rho=3.1g/mL[/tex]
Explanation:
Hello,
In this case, considering that the density of a body is computed given its mass and volume:
[tex]\rho =\frac{m}{V}[/tex]
Taking into account that the mass is 24.32 g and the volume is computed via the difference between the volume of the water with the brass and the volume of water by itself as follows:
[tex]V=13.50mL-5.60mL=7.9mL[/tex]
The density of the piece of brass turns out:
[tex]\rho =\frac{24.32g}{7.9mL}\\\\\rho=3.1g/mL[/tex]
Best regards.
