please do this guys i need a lot of help please!
Answer:
the European countries grew together.
Explanation:
Europe saw human inflows from east and southeast.
the Roman Empire came to dominate the entire Mediterranean basin.
European politics from 1947 to 1989 made the European countries grew together.
Which diagram correctly describes the changes that occur as a small piece of rock falls from space and hits the earth
Answer:
the motion of gravity
Explanation:
Answer:
its c
Explanation
advhuosijoklxcmnjdabsuhggggabciaciudeifweingivg eygerigsygfe97rsghisdcvhbsduigwiugfu9uigdgiurfgyisdgfsdgfegiygewifgsdygfewusgfuyesigf7wgfiesgfiusgdfies
Based on the diagram below, how much of the excess reactant is left over? *
2 slices of bread and 3 pieces of lunchmeat
2 slices of bread and 2 slices of cheese
2 of lunchmeat and 3 slices of cheese
3 of lunchmeat and 2 slices of cheese
Answer:
3 pieces of lunch-meat and 2 slices of cheese
Explanation:
You have enough bread to make 3 sandwiches
You have enough lunch-meat to make 4 sandwiches
You have enough cheese to make 5 sandwiches
In all you have enough material to make 3 sandwiches
so if you subtract three from each number above you will have no bread, enough lunch-meat to make one sandwich and enough cheese to make two sandwiches
luch-meat for one sandwich is: 3 pieces
Cheese for two sandwiches is: 2 pieces
does the reaction Fe + CuNO3 occur
Answer:
yes
Explanation:
Please answers only , 100 pts and brainliest, wrong answers will be reported.
What is the molarity of 9.8 gram Sulfuric Acid in 500 mL of water?
Answer:
.2mol/L
Explanation:
Answer:
2mol/l
Explanation:
.The pH is 3. What is [H+]? *
1 point
0.001
0.01
100
1000
Answer:
0.001 M
Explanation:
The pH scale is used to determine the acidity or basicity of a solution.
If pH < 7, the solution is acid.If pH = 7, the solution is neutral.If pH > 7, the solution is basic.The pH is related to the concentration of hydrogen ions through the following expression.
pH = -log [H⁺]
[H⁺] = antilog -pH = antilog - 3 = 0.001 M
if a sample of gas at 25.2 c has a volume of 536mL at 637 torr, what will its volume be if the pressure is increased to 712 torr?
PLEASE HELP!!!! How many moles of helium are needed to fill a balloon to a volume of 4.9 at 296°K and 0.78 atm?
Answer:
THE NUMBER OF MOLES OF HELIUM NEEDED TO FILL A BALLOON AT A VOLUME OF 4.9 L AT 296 K AND 0.78 atm IS 0.00338 moles.
Explanation:
The number of moles is calculated using
PV = nRT
P = Pressure = 0.78 atm
V = volume = 4.9 L
R = gas constant = 0.082 Latm/molK
T = temperature = 296 K
n= number of moles
Substituting theses values and sloving for n, we obtain;
n = PV / RT
n = 0.78 * 4.9 / 0.082 * 296
n = 3.822 / 24.272
n = 0.00338 moles.
So therefore, the number of moles is 0.00338 moles.
Answer:
The number of moles of helium needed is 0.157 moles helium
Explanation:
Step 1: Data given
Volume of the balloon = 4.9 L
Temperature= 296 K
Pressure = 0.78 atm
Step 2: Calculate moles of helium gas
p*V = n*R*T
⇒with p = the pressure = 0.78 atm
⇒with V = the volume = 4.9 L
⇒with n = the number of moles of the helium gas = TO BE DETERMINED
⇒with R = the gas constant = 0.08206 L*atm/mol* K
with T = the temperature = 296 K
n = (p*V) / (R*T)
n = (0.78 atm* 4.9 L) / (0.08206 L*atm/mol*K * 296 K)
n = 0.157 moles of helium
The number of moles of helium needed is 0.157 moles helium
A solution is prepared by mixing 525 mL of ethanol with 597 mL of water. The molarity of ethanol in the resulting solution is 8.35 M. The density of ethanol at this temperature is 0.7893 g/mL. Calculate the difference in volume between the total volume of water and ethanol that were mixed to prepare the solution and the actual volume of the solution. g
Answer:
[tex]\Delta V = 234.736\,mL[/tex]
Explanation:
The quantity of moles of ethanol in the solution is:
[tex]n_{C_{2}H_{5}OH} = \left(\frac{597\,mL}{1000\,mL} \right)\cdot \left(8.35\,\frac{mol}{L} \right)[/tex]
[tex]n_{C_{2}H_{5}OH} = 4.985\,mol[/tex]
The mass and volume of ethanol in the solution are, respectively:
[tex]m_{C_{2}H_{5}OH} = (4.985\,mol)\cdot \left(46.07\,\frac{g}{mol} \right)[/tex]
[tex]m_{C_{2}H_{5}OH} = 229.658\,g[/tex]
[tex]V_{C_{2}H_{5}OH} = \frac{229.658\,g}{0.7893\,\frac{g}{mL} }[/tex]
[tex]V_{C_{2}H_{5}OH} = 290.964\,mL[/tex]
The difference between the total volume of water and ethanol mixed to prepare the solution and the actual volume of solution is:
[tex]\Delta V = (525\,mL+597\,mL) - (597\,mL + 290.964\,mL)[/tex]
[tex]\Delta V = 234.736\,mL[/tex]
The difference in volume between the total volume of water and ethanol is ΔV =234.736 mL.
Calculation for moles of ethanol:The quantity of moles of ethanol in the solution is:
[tex]nC_2H_5OH=\frac{597mL}{1000mL} *8.35mol/L\\\\nC_2H_5OH=4.985 moles[/tex]
The mass and volume of ethanol in the solution are, respectively:
[tex]mC_2H_5OH=4.985moles*46.07g/mol\\\\mC_2H_5OH=229.685g[/tex]
[tex]VC_2H_5OH=\frac{229.685g}{0.7893g/mL} \\\\VC_2H_5OH=290.964mL[/tex]
The difference between the total volume of water and ethanol mixed to prepare the solution and the actual volume of solution is:
ΔV= (525mL+597mL)- (597mL + 290.964 mL)
ΔV= 234.736mL
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What is the name for s2o7
Answer:
Disulfate Ion {2-} Name: Disulfate Ion {2-} Formula: S2O7.
Explanation:
HOPE THIS HELPED :)
Answer:
Pyrosulfate
In chemistry, disulfate or pyrosulfate is the anion with the molecular formula S₂O²⁻₇. Disulfate is the IUPAC name. It has a dichromate-like structure and can be visualised as two corner-sharing SO₄ tetrahedra, with a bridging oxygen atom. In this anion, sulfur has an oxidation state of +6. Disulfate is the conjugate base of the hydrogen disulfate ion HS₂O⁻₇, which in turn is the conjugate base of disulfuric acid.
Explanation:
In chemistry, disulfate or pyrosulfate is the anion with the molecular formula S 2O2− 7. Disulfate is the IUPAC name. It has a dichromate -like structure and can be visualised as two corner-sharing SO 4 tetrahedra, with a bridging oxygen atom. In this anion, sulfur has an oxidation state of +6.
Salt in crude oil must be removed before the oil undergoes processing in a refinery. The
crude oil is fed to a washing unit where freshwater fed to the unit mixes with the oil and
dissolves a portion of the salt contained in the oil. The oil (containing some salt but no
water), being less dense than the water, can be removed at the top of the washer. If the
“spent” wash water contains 15% salt and the crude oil contains 5% salt, determine the
concentration of salt in the “washed” oil product if the ratio of crud oil (with salt) to
water used is 4:1.
Answer:
[tex]\large \boxed{0.64 \, \%}[/tex]
Explanation:
Assume you are using 1 L of water.
Then you are washing 4 L of salty oil.
1. Calculate the mass of the salty oil
Assume the oil has a density of 0.86 g/mL.
[tex]\text{Mass of oil} = \text{4000 mL} \times \dfrac{\text{0.86 g}}{\text{1 mL}} = \text{3440 g}[/tex]
2. Calculate the mass of salt in the salty oil
[tex]\text{Mass of salt} = \text{3440 g} \times \dfrac{\text{5 g salt}}{\text{100 g oil}} = \text{172 g salt}[/tex]
3. Calculate the mass of salt in the spent water
[tex]\text{Mass of salt} = \text{1000 g water} \times \dfrac{\text{15 g salt}}{\text{100 g water}} = \text{150 g salt}[/tex]
4. Mass of salt remaining in washed oil
Mass = 172 g - 150 g = 22 g
5. Concentration of salt in washed oil
[tex]\text{Concentration} = \dfrac{\text{22 g}}{\text{3440 g}} \times 100 \, \% = \mathbf{0.64 \, \%}\\\\\text{The concentration of salt in the washed oil is $\large \boxed{\mathbf{0.64 \, \%}}$}[/tex]
If you start with 64g of a radioactive element how many half-lives would occur before 8g remain?
Answer:
3 half-lives
Explanation:
The half-life is the time that it takes to a radioactive element to decay to half of its initial amount.
Let's suppose we start with 64 g of the radioactive element.
After 1 half-life, the mass of the element will be 32 g.After 2 half-lives, the mass of the element will be 16 g.After 3 half-lives, the mass of the element will be 8 g.Question 13: Consider the strength of the Hβ absorption line in the spectra of stars of various surface temperatures. This is the amount of light that is missing from the spectra because Hydrogen electrons have absorbed the photons and jumped from level 2 to level 4. How do you think the strength of Hβ absorption varies with stellar surface temperature?
Answer:
The absorption and strength of the H-beta lines change with the temperature of the stellar surface, and because of this, one can find the temperature of the star from their absorption lines and strength. To better comprehend, let us look into the concept of the atom's atomic structure.
Atoms possess distinct energy levels and these levels of energy are constant, that is, the temperature has no influence on it. However, temperature possesses an influence on the electron numbers found within these levels of energy. Therefore, to generate an absorption line of hydrogen in the electromagnetic spectrum's visible band, the electrons are required to be present in the second energy level, that is when it captivates a photon.
Therefore, after captivating the photons the electrons jump from level 2 to level 4, which shows that there is an increase in the stellar surface temperature and at the same time one can witness a decline in the strength of the H-beta lines. In case, if the temperature of the surface increases too much, then one will witness no attachment of electron with the hydrogen atom and thus no H lines, and if the temperature of the surface becomes too low, then the electrons will stay in the ground state and no formation of H lines will take place in that condition too.
Hence, to generate a very robust H line, after captivating photons the majority of the electrons are required to stay in the second energy level.
What is the total amount of energy needed to heat 22.6 g of titanium from 1420oC to 1590oC in joules?
Answer:
[tex]Q=2091J=2.091kJ[/tex]
Explanation:
Hello,
In this case, the formula we use to compute the heat Q by increasing the temperature, in terms of the mass and the heat capacity is:
[tex]Q=mCp(T_2-T_1)[/tex]
Titanium's heat capacity is 0.544284 J/g°C, thus, the for such temperature increase, the heat results positive as shown below:
[tex]Q=22.6g*0.544284\frac{J}{g^oC}*(1590^oC-1420^oC) \\\\Q=2091J=2.091kJ[/tex]
Best regards.
is the normal resting position of an object.
Answer:
being stationary relative to a particular frame of reference or another object; when the position of a body with respect to its surroundings does not change with time it is said to be at rest
Explanation:
Been stationary is the normal resting position of an object
When an object is at rest ( normal resting position ) it is stationary ( i.e. the position of the object does not change with time in relation to its environment or another object/reference )
When an object is at rest it posses its' highest potential energy and its least kinetic energy. therefore been stationary is the normal resting position of an object.
Hence we can conclude that Been stationary is the normal resting position of an object.
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What is the binding energy of a mole of nuclei with a mass defect of 0.00084 kg/mol?
Answer:
The binding energy of a mole of the nuclei is 252KJ
Explanation:
The binding energy is the amount of energy required to separate an atom into its nuclei.
From Einstein's relations,
E = Δm[tex]c^{2}[/tex]
where E is the energy, Δm is the mass defect and c is the speed.
The mole of nuclei moves with the speed of light, so that;
c = 3.0 × [tex]10^{8}[/tex] m/s
Given that Δm = 0.00084Kg/mol, the binding energy is calculated as;
E = 0.00084 × 3.0 × [tex]10^{8}[/tex]
= 252000
= 252KJ
The binding energy of a mole of the nuclei is 252KJ.
Answer:
7.55×10^10 KJmol-1
Explanation:
The actual mass of a nucleus is usually less than the sum of the masses of the constituent neutrons and protons that make up the nucleus. This difference is called the mass defect.
The mass defect is related to the binding energy holding the neutrons and protons together in the nucleus. Since energy and mass are related by Einstein's equation;
E=∆mc^2 where;
E = binding energy of the nucleus
∆m= mass defect of the nucleus
c= speed of light
The larger the mass defect, the larger the binding energy of the nucleus and the more stable the nucleus.
From the data provided;
Mass defect= 0.00084 kg/mol or 0.84g/mol
Since 1 g/mol= 1 amu
0.84g/mol= 0.84 amu
The conversion factor from atomic mass units to MeV is 931
Binding energy = 0.84 × 931= 782.04 MeV
Since 1eV= 96.49KJmol-1
782.04×10^6eV= 7.55×10^10 KJmol-1
Helium occupies a volume of 3.8 L at –45°C. What was its initial temperature when it occupied 8.3 L?
Answer:
98.3 gradius Celsius
Explanation:
This problem is solved using the Ideal Gas Equation
pV = nRT
...
Please see the step-by-step solution in the picture attached below.
Hope this answer can help you. Have a nice day!
What is science? Answer for brainilest
Answer:
The importance of learning is that it helps the individual to acquire the necessary skills through learning and knowledge so that he can achieve his set goals. An important fact about learning is that it is a means to improve knowledge and gain skills that will help in reaching specific goals
Explanation:
The importance of learning is that it helps the individual to acquire the necessary skills through learning and knowledge so that he can achieve his set goals. An important fact about learning is that it is a means to improve knowledge and gain skills that will help in reaching specific goals
Write and balance the double replacement reaction between barium sulfate and titanium (II) oxide.
Answer:
BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)
Explanation
The equation for the reaction between barium sulfate and titanium (II) oxide is given below:
BaSO4 + TiO —>
In solution, the reactants will dissociates as follow:
BaSO4(aq) —> Ba^2+(aq) + SO4^2-(aq)
TiO(aq) —> Ti^2+(aq) + O^2-(aq)
The double displacement reaction will occur as follow:
Ba^2+(aq) + SO4^2-(aq) + Ti^2+(aq) + O^2-(aq) —> Ba^2+O^2-(aq) + Ti^2+SO4^2-(aq)
We can see that a double displacement reaction occurred as there is a double exchange of ions in the solution. The elemental equation is given below:
BaSO4(aq) + TiO(aq) —> BaO(aq) + TiSO4(aq)
Nikolas, the fire extinguisher, and the skateboard have a combined mass of 50 kg. What force would the fire extinguisher have to produce to propel nikolas if he wanted to accelerate at a rate of 1.2 m/s squared
Answer:
Force used by fire extinguisher = 60 N
Explanation:
Given:
Mass of skateboard with fire extinguisher = 50 kg
Acceleration of fire extinguisher = 1.2 m/s²
Find:
Force used by fire extinguisher = ?
Computation:
⇒ Force = Mass × Acceleration
⇒ Force used by fire extinguisher = Mass of skateboard with fire extinguisher × Acceleration of fire extinguisher
⇒ Force used by fire extinguisher = 50 kg × 1.2 m/s²
⇒ Force used by fire extinguisher = 60 N
Answer:
Force=60 N
Hope this helps ya'll!
PbCl2+ AgNO3------>Pb(NO3)2+ AgCl
Decomposition
Synthesis
Double displacement
Exothermic
Answer:
Option C
Explanation:
A double displacement reaction is the one in which two chemical compounds having a cation and anion in each exchange their positive and negative ions thereby forming new compounds or products.
Here,
The first compound [tex]PbCl_2[/tex] has a positive ion [tex]Pb[/tex] and negative ion [tex]Cl^-[/tex]
Like wise the second compound [tex]Ag(NO_3)[/tex] has a positive ion [tex]Ag[/tex] and negative ion [tex]NO_3[/tex]
The new compounds will be formed when cation of one compound attaches with the anion of other compound. Hence the new compounds are
[tex]Pb(NO_3)_2[/tex]
[tex]AgCl[/tex]
This is example of double displacement reaction.
Option C is correct
A gas in a piston–cylinder assembly undergoes a compression process for which the relation between pressure and volume is given by p = AV2 + BV-2 (p is in bar and V is in m3). The initial volume is 0.1 m3, and the initial pressure is 1 bar. The final volume is 0.04 m3, and the final pressure is 2 bar. Determine:
Answer:
1.
[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]
2. [tex]W=-8.2kPa[/tex]
Explanation:
Hello,
1. In this case, for the given p-V equation, one could use the two states to form a 2x2 linear system of equations in terms of A and B:
[tex]\left \{ {{0.1^2A+0.1^{-2}B=1} \atop {0.04^2A+0.04^{-2}B=2}} \right.[/tex]
[tex]\left \{ {{0.01A+100B=1} \atop {0.0016A+625B=2}} \right[/tex]
Whose solution by any method for solving 2x2 linear system of equations (elimination, reduction or substitution) is:
[tex]A=69.8\frac{bar}{m^6}\\\\ B=0.00302bar*m^6[/tex]
2. Now, for us to compute the work, we must first compute n, as the power relating the pressure and volume for this process:
[tex]P_1V_1^n=P_2V_2^n\\\\\frac{P_1}{P_2}=(\frac{V_2}{V_1} )^n\\\\\frac{1bar}{2bar}= (\frac{0.04m^3}{0.1m^3} )^n\\\\0.5=0.4^n\\\\n=\frac{ln(0.5)}{ln(0.4)} =0.7565[/tex]
Now, we compute the work:
[tex]W=\frac{P_2V_2-P_1V_1}{1-n} =\frac{2bar*0.04m^3-1bar*0.1m^3}{1-0.7565} \\\\W=-0.082bar*m^3*\frac{1x10^2kPa}{1bar}\\ \\W=-8.2kPa[/tex]
Regards.
If I add 50 mls of water to 300 mls of 0.6M KNO3 solution, what will be the molarity of the diluted solution?
Answer:
[tex]M_2=0.51M[/tex]
Explanation:
Hello,
In this case, for this dilution process, we understand that the moles of the solute (potassium nitrate) remain unchanged upon the addition of diluting water. However, the resulting or final volume includes the added water as shown below:
[tex]V_2=300mL+50mL=350mL[/tex]
In such a way, we are able to relate the solution before and after the dilution by:
[tex]V_1M_1=V_2M_2[/tex]
Hence, we solve for the final molarity as:
[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.6M*300mL}{350mL}[/tex]
Best regards.
[tex]M_2=0.51M[/tex]
How do you calculate the number of protons, neutrons, and electrons in an element?
Answer:
The first thing you will need to do is find some information about your element. Go to the Periodic Table of Elements and click on your element. If it makes things easier, you can select your element from an alphabetical listing.
Number of Protons = Atomic Number
Number of Electrons = Number of Protons = Atomic Number
Number of Neutrons = Mass Number - Atomic Number
For krypton:
Number of Protons = Atomic Number = 36
Number of Electrons = Number of Protons = Atomic Number = 36
Number of Neutrons = Mass Number - Atomic Number = 84 - 36 = 48
Explanation:
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3. Infer A forgotten ice pop lies melting on a deck on a hot summer day. What is the direction of heat flow as the ice pop melts?
Is the process endothermic or exothermic? Explain.
Answer:
Endothermic. The energy is flowing into the molecules causing them to break apart and the ice pop change state.
Answer:
Yes, an autumn day isn’t cold enough to keep an ice pop at freezing temperatures.
The glass of a lit 75-watt incandescent bulb is hotter to the touch than the glass of a 25-watt compact fluorescent (CFL) bulb that emits the same amount of light. What could be a reason for this
What are the three components of the cell theory?
Answer:
IN the description
Explanation:
The generally accepted parts of modern cell theory include:
All known living things are made up of one or more cells. All living cells arise from pre-existing cells by division. The cell is the fundamental unit of structure and function in all living organisms.
Answer:
Sample Response: The first component of the cell theory says that all living things are made of cells. The second component of the cell theory states that cells are the basic structure and function of living things. The last component of the cell theory says that cells come from other cells.
I'll give you 100 points
Which are evidence of seafloor spreading? Select three options. A.molten material B.magnetic stripes C.continent material D.drilled core samples E.ocean water samples
How many moles
are equal to
4.11x1023
molecules of
CO2?
Explanation:
6.02×1023 culture atoms have a mass of 63.5g. 12.0g. c +23.0g O2__44.0g CO2.(12.0+16.0+16.0=44.0g).1 mol 1 mol. 1 mol number molecules weight
The number of molecules in one mole of carbon dioxide is 6.02 × 10²³. Therefore, the number of moles of carbon dioxide which contains 4.11 × 10²³ molecules is 0.68.
What is Avogadro number ?The number of atoms that constitutes one mole of a substance is called Avogadro number. It is equal to 6.02 × 10²³. Thus, one mole of every elements contains Avogadro number of atoms.
Similarly, one mole of a compound contains 6.02 × 10²³ number of molecules. Thus, one mole of carbon dioxide contains these much molecules.
Given the number of molecules of carbon dioxide = 4.11 × 10²³
Then, no.of moles = number of molecules/ Avogadro number.
no.of moles = 4.11 × 10²³ /6.022 × 10²³ = 0.68.
Therefore, the number of moles of CO₂ that contains 4.11 × 10²³ molecules is 0.68.
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At constant pressure, what generally happens to the solubility of solids and gases when the temperature of a solution is increased?
A. The solubility of solids and gases increases.
B. The solubility of solids and gases decreases.
C. The solubility of solids increases, and the solubility of gases decreases.
D. The solubility of solids decreases, and the solubility of gases increases.
Answer:
C)
Explanation:
JUST DID IT
Answer:
A D E
Explanation:
just did it