Objects with more mass have more gravity. Gravity also gets weaker with distance. So, the closer objects are to each other, the stronger their gravitational pull is. Earth's gravity comes from all its mass.
Answer:
the moon or the sun
Explanation:
Worked with radium to learn about radioactive elements.
Answer:
WHat did u mean?
Consider the titration of a 20.0-mL sample of 0.105 M HC2H3O2 with 0.125 M NaOH. Determine each quantity. a. the initial pH b. the volume of added base required to reach the equivalence point c. the pH at 5.0 mL of added base d. the pH at one-half of the equivalence point e. the pH at the equivalence point f. the pH after adding 5.0 mL of base beyond the equivalence point
Answer:
Explanation:
Given that:
Concentration of [tex]HC_2H_3O_2 \ (M_1)[/tex] = 0.105 M
Volume of [tex]HC_2H_3O_2 \ (V_1)[/tex] = 20.0 mL
Concentration of [tex]NaOH (M_2)[/tex] = 0.125 M
The chemical reaction can be expressed as:
[tex]HC_2H_3O_2_{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O_{(l)}[/tex]
Using the ICE Table to determine the equilibrium concentrations.
[tex]HC_2 H_3 O_2 _{(aq)} + H_2O _{(l) } \to C_2 H_3O_2^- _{(aq)} + H_3O^+_{ (aq)}[/tex]
I 0.105 0 0
C -x +x +x
E 0.105 - x x x
[tex]K_a = \dfrac{[C_2H_5O^-_2][H_3O^+]}{[HC_2H_3O_2]}[/tex]
[tex]K_a = \dfrac{(x)(x)}{(0.105-x)}[/tex]
Recall that the ka for [tex]HC_2H_3O_2= 1.8 \times 10^{-5}[/tex]
Then;
[tex]1.8 \times 10^{-5} = \dfrac{(x)(x)}{(0.105 -x)}[/tex]
[tex]1.8 \times 10^{-5} = \dfrac{x^2}{(0.105 -x)}[/tex]
By solving the above mathematical expression;
x = 0.00137 M
[tex]H_3O^+ = x = 0.00137 \ M \\ \\ pH = - log [H_3O^+] \\ \\ pH = - log ( 0.00137 )[/tex]
pH = 2.86
Hence, the initial pH = 2.86
b) To determine the volume of the added base needed to reach the equivalence point by using the formula:
[tex]M_1 V_1 = M_2 V_2[/tex]
[tex]V_2= \dfrac{M_1V_1}{M_2}[/tex]
[tex]V_2= \dfrac{0.105 \ M \times 20.0 \ mL }{0.125 \ M}[/tex]
[tex]V_2 = 16.8 mL[/tex]
Thus, the volume of the added base needed to reach the equivalence point = 16.8 mL
c) when pH of 5.0 mL of the base is added.
The Initial moles of [tex]HC_2H_3O_2 =[/tex] molarity × volume
[tex]= 0.105 \ M \times 20.0 \times 10^{-3} \ L[/tex]
[tex]= 2.1 \times 10^{-3}[/tex]
number of moles of 5.0 NaOH = molarity × volume
number of moles of 5.0 NaOH = [tex]0.625 \times 10^{-3}[/tex]
After reacting with 5.0 mL NaOH, the number of moles is as follows:
[tex]HC_2 H_3 O_2 _{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O{ (l)}[/tex]
Initial moles [tex]2.1*10^{-3}[/tex] [tex]0.625 * 10^{-3}[/tex] 0 0
F(moles) [tex](2.1*10^{-3} - 0.625 \times 10^{-3})[/tex] 0 [tex]0.625 \times 10^{-3}[/tex] [tex]0.625 \times 10^{-3}[/tex]
The pH of the solution is then calculated as follows:
[tex]pH = pKa + log \dfrac{[base]} {[acid]}[/tex]
Recall that:
pKa for [tex]HC_2H_3O_2=4.74[/tex]
Then; we replace the concentration with the number of moles since the volume of acid and base are equal
∴
[tex]pH = 4.74 + log \dfrac{0.625 \times 10^{-3}}{1.475 \times 10^{-3}}[/tex]
pH = 4.37
Thus, the pH of the solution after the addition of 5.0 mL of NaOH = 4.37
d)
We need to understand that the pH at 1/2 of the equivalence point is equal to the concentration of the base and the acid.
Therefore;
pH = pKa = 4.74
e) pH at the equivalence point.
Here, the pH of the solution is the result of the reaction in the [tex](C_2H_3O^-_2)[/tex] with [tex]H_2O[/tex]
The total volume(V) of the solution = V(acid) + V(of the base added to reach equivalence point)
The total volume(V) of the solution = 20.0 mL + 16.8 mL
The total volume(V) of the solution = 36.8 mL
Concentration of [tex](C_2H_3O^-_2)[/tex] = moles/volume
= [tex]\dfrac{2.1 \times 10^{-3} \ moles}{0.0368 \ L}[/tex]
= 0.0571 M
Now, using the ICE table to determine the concentration of [tex]H_3O^+[/tex];
[tex]C_2H_5O^-_2 _{(aq)} + H_2O_{(l)} \to HC_2H_3O_2_{(aq)} + OH^-_{(aq)}[/tex]
I 0.0571 0 0
C -x +x +x
E 0.0571 - x x x
Recall that the Ka for [tex]HC_2H_3O_2[/tex] = [tex]1.8 \times 10^{-5}[/tex]
[tex]K_b = \dfrac{K_w}{K_a} = \dfrac{1.0\times 10^{-14}}{1.8 \times 10^{-5} } \\ \\ K_b = 5.6 \times 10^{-10}[/tex]
[tex]k_b = \dfrac{[ HC_2H_3O_2] [OH^-]}{[C_2H_3O^-_2]}[/tex]
[tex]5.6 \times 10^{-10} = \dfrac{x *x }{0.0571 -x}[/tex]
[tex]x = [OH^-] = 5.6 \times 10^{-6} \ M[/tex]
[tex][H_3O^+] = \dfrac{1.0 \times 10^{-14} }{5.6 \times 10^{-6} }[/tex]
[tex][H_3O^+] =1.77 \times 10^{-9}[/tex]
[tex]pH =-log [H_3O^+] \\ \\ pH =-log (1.77 \times 10^{-9}) \\ \\ \mathbf{pH = 8.75 }[/tex]
Hence, the pH of the solution at equivalence point = 8.75
f) The pH after 5.09 mL base is added beyond (E) point.
[tex]HC_2 H_3 O_2 _{(aq)} + NaOH _{(aq)} \to NaC_2H_3O_2_{(aq)} + H_2O{ (l)}[/tex]
Before 0.0021 0.002725 0
After 0 0.000625 0.0021
[tex][OH^-] = \dfrac{0.000625 \ moles}{(0.02 + 0.0218 ) \ L}[/tex]
[tex][OH^-] = \dfrac{0.000625 \ moles}{0.0418 \ L}[/tex]
[tex][OH^-] = 0.0149 \ M[/tex]
From above; we can determine the concentration of [tex]H_3O^+[/tex] by using the following method:
[tex][H_3O^+] = \dfrac{1.0 \times 10^{-14} }{0.0149}[/tex]
[tex][H_3O^+] = 6.7 \times 10^{-13}[/tex]
[tex]pH = - log [H_3O^+][/tex]
[tex]pH = -log (6.7 \times 10^{-13} )[/tex]
pH = 12.17
Finally, the pH of the solution after adding 5.0 mL of NaOH beyond (E) point = 12.17
Copper(II) chloride hydrate, also known as copper chloride hydrate, is the inorganic compound with the chemical formula CuCl2 . x(H2O), where x can range from 1 to 7. A 2.060 g sample of copper (II) chloride hydrate was dissolved in 50.0 mL of deionized water. The concentration of copper (II) ion in the solution was determined spectrophotometrically using the equation from the calibration curve, was 0.200 M. Determine the formula of the copper (II) chloride hydrate.
Answer:
CuCl₂·4H₂O
Explanation:
First we calculate the moles of copper (II) ion in the solution, using the given volume and concentration:
50.0 mL ⇒ 50.0/1000 = 0.05 L0.05 L * 0.200 M = 0.01 mol Cu⁺²For each Cu⁺² mol there's also one CuCl₂ mol.
We convert 0.01 CuCl₂ moles into grams, using its molar mass:
0.01 CuCl₂ mol * 134.45 g/mol = 1.344 gThat means that out of the 2.060 g of the sample, 1.344 g are of CuCl₂. This means that there are (2.060 - 1.344) 0.716 g of water.
We convert those 0.716 g of water to moles:
0.716 g ÷ 18 g/mol = 0.04 mol H₂OThere are four times as many H₂O moles as there are CuCl₂ moles. This means the formula is CuCl₂·4H₂O
In the desert, wind picks up and carries fine particles of sand and dirt. As 5 points
the wind blows against the rocks, the particles rub against the rocks and
wear them down in a process called: *
Weathering
Erosion
Deposition
Compaction/Cementation
What are the four Earth systems that contribute to the rock cycle?
C
It’s wrong I need points
The rock cycle includes the geosphere, hydrosphere, biosphere, and atmosphere. The wearing of the rock particles is called weathering. Thus, option a is correct.
What is weathering?Weathering is the process of sediment formation where the parent rocks and substances get disintegrated through natural biochemical and physical factors.
The parent rocks get deteriorated into smaller fine particles and sediments by the action of the strong wind and water. The movement causes the particles to dissolve the minerals on the surface.
The method of weathering, erosion, deposition, and compaction/ cementation is the part of the rock cycle that comprises the four major spheres including geosphere, hydrosphere, biosphere, and atmosphere.
Therefore, option a. in weathering the particles get disintegrated due to air and water.
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Many food chains together create a______
Science
What part of all organisms Is involved in the exchanging of gases
Answer:
Gas exchange occurs in microscopic dead-end air-filled sacs called alveoli, where a very thin membrane (called the blood-air barrier) separates the blood in the alveolar capillaries (in the walls of the alveoli) from the alveolar air in the sacs.
Explanation:
Calculate the relative formula mass of Zn(NO3)2. Round your answer to the nearest whole number?
Answer:
189
Explanation:
189
The relative formula mass of Zn(NO₃)₂ is 189.38g.
How do we calculate the mass of any compound?Molecular mass of any formula of compound will be calculated by adding the molar mass of each atoms present in the given compound.
Molecular mass of Zn(NO₃)₂ = Sum of the molar mass of Zinc, nitrogen and oxygen atoms.
Molecular mass of Zn(NO₃)₂ = 65.38g/mol + 2(14g/mol) + 6(16g/mol) = 189.38g
Hence the required mass of Zn(NO₃)₂ is 189.38g.
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Write everything that you know about atoms and how they relate to matter.
What mass of HBO2 is produced from the
combustion of 139.5 g of B2H6?
Answer in units of g.
Answer:
[tex]m_{HBO_2}=441.8gHBO_2[/tex]
Explanation:
Hello there!
In this case, since the combustion of B2H6 is:
[tex]B_2H_6+3O_2\rightarrow 2HBO_2+2H_2O[/tex]
Thus, since there is 1:2 mole ratio between the reactant and product, the produced grams of the latter is:
[tex]m_{HBO_2}=139.5gB_2H_6*\frac{1molB_2H_6}{27.67gB_2H_6} *\frac{2molHBO_2}{1molB_2H_6} *\frac{43.82gHBO_2}{1molHBO_2}[/tex]
[tex]m_{HBO_2}=441.8gHBO_2[/tex]
Best regards!
Hard water often contains dissolved Ca^2+ and Mg^2+ ions. One way to soften water is to add phosphates. The phosphate ion forms insoluble precipitates with calcium and magnesium ions, removing them from solution. A solution is 0.055 MM in calcium chloride and 0.075 MM in magnesium nitrate. What mass of sodium phosphate would you add to 1.0 LL of this solution to completely eliminate the hard water ions? Assume complete reaction.
Answer:
14.2g of sodium phosphate are required
Explanation:
To solve this question we need to find the moles of Ca²⁺ and Mg²⁺ ions. And based on the reactions:
3Ca²⁺ + 2PO₄³⁻ → Ca₃(PO₄)₂ (s)
3Mg²⁺ + 2PO₄³⁻ → Mg₃(PO₄)₂ (s)
we can find the moles of phosphate required to precipitate all these ions and its mass:
Moles Ca²⁺:
1.0L * (0.055mol / L) = 0.055mol
Moles Mg²⁺:
1.0L * (0.075mol / L) = 0.075mol
Total moles = 0.13 moles of ions
Moles of phosphate ion required:
0.13 moles * (2 moles PO₄³⁻ / 3 moles ions) = 0.0867 moles PO₄³⁻
The moles of sodium phosphate (Na₃PO₄) are = 0.0867 moles
The mass is -Molar mass Na₃PO₄: 164g/mol-:
0.0867 moles Na₃PO₄ * (164g / mol) =
14.2g of sodium phosphate are requiredGauging yourself against others is acceptable in competitive sports.
Answer:
Yup it is acceptable.
U comparing yourself will place u above and below some people for sure.
So you will know to where you have to develop and can get yourself satisfied as you will be above some people.
Gauging yourself against others is acceptable in competitive sports is acceptable.
What is Competitive sports?Faster, higher, stronger is the Olympic motto frequently used in competitive sports. The Olympic slogan "To be there is everything" causes confusion, although it is actually highly false and the complete reverse.
Competitive athletes receive a planned training program. To attain particular objectives, the quantity and quality of each individual training block are carefully calculated.
The scope, duration, number, and load of each individual training unit are adjusted according to the level of fitness and the proximity to the season's peak throughout the year.
Therefore, Gauging yourself against others is acceptable in competitive sports is acceptable.
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How do scientist prevent biases from affecting their data?
A. Scientist base their data off their personal feelings and options.
B. Scientist will ask their family members for their own options.
C. Scientist will ask the option of other scientists.
D. Scientist ignore their own personal feelings and interpret data objectively.
Answer:
Answer should be D. Scientists ignore their own person feelings and interpret data objectively.
What is the numerical value of the rate constant for a reaction in which [A] is reduced from 0.380 M to 0.215 M in a span of 26.3 s? Assume the units of the rate constant are s-1. Please enter your response to three of significant figures using E notation. For example, to report 1347.54 to three significant figures, type: 1.35E3
Answer:
k = 2.17E-2 s-1
Explanation:
Initial Concentration [A]o = 0.380 M
Final Concentration [A] = 0.215 M
time, t = 26.3 s
Unit of rate constant = s-1
Rate constant = ?
The units of the rate constant depends on the order of the reaction. This is a first order reaction due to the units.
The integral rate law for a first order reaction is;
ln[A] = ln[A]o - kt
ln(0.215) = ln(0.380) - k(26.3)
ln(0.215) - ln(0.380) = - k(26.3)
- k(26.3) = -0.57
k = 0.57 / 26.3 = 0.02167
Reporting to three significant figures using E notation;
k = 2.17E-2 s-1
6. What is the highest
labeled point on the
map?
7. What is the difference
in elevation between the
highest point on the map
and point W?
8. Which letter (W.XY
or Z) represents a
gentle slope?
9. What is the elevation
of point X?
Answer: I think 35
Explanation:
Which of the following variables has the least effect on the rate a substance dissolved in a container of water?
A. The force of the stirring
B. The size of the container
C. The temperature of the water
D. The surface area of the substance
give the result of the following expression with the correct number of significant figures
[tex]84 \frac{m}{s} \times 32.533s[/tex]
Determine whether each of the molecules below is polar or nonpolar. Tetrahedral C C l 4 CClX4 Nonpolar Tetrahedral C H 3 O H CHX3OH Polar Trigonal pyramidal N H 3 NHX3 Nonpolar Linear C S 2 CSX2 Nonpolar
Answer:
CCl4 - Nonpolar
CH3OH - polar
NH3 - polar
CS2 - Nonpolar
Explanation:
One important thing that we should know is that polarity has to do with the presence of a resultant dipole moment in a molecule.
Dipole moment is a vector quantity, This means that its direction is also taken into account when discussing the dipole moment of molecules.
Hence, symmetrical molecules such as CS2 and CCl4 are non-polar even though they have polar bonds because their dipoles cancel out(zero resultant dipole moment).
On the other hand, NH3 and CH3OH are non-symmetrical molecules hence they possess an overall dipole moment and are polar molecules.
What is the relationship between an object’s height above the ground and its gravitational potential energy?
Answer:
Explanation:
The formula for gravitational potential energy is the mass*gravity*height. Therefore, the greater the distance from the ground, the higher the gravitational potential energy.
Answer: The amount of gravitational potential energy an object has depends on mass of the object and height of the object above ground. Objects that are at large height above the ground have more potential energy. Similarly, objects that are at small height above the ground have less potential energy.
The function of this organelle is to create energy (ATP) through the process of cellular respiration.
Answer choices:
A. lysosome
B. endoplasmic reticulum
C. mitochondrion
D. golgi apparatus
Answer:
C
Explanation:
I hope this is correct and have a great day
Organelles______are specialized structures that carry out particular jobs and functions?
Given the formula of a compound
What is the molecular formula for this compound?
1.
CH
2.
CH2
3.
CH3
4.
C₃H6
Answer:
4
Explanation:
three carbon atoms combined with six hydrogen atoms
There are two types of chemical compound one is covalent compound and other is ionic compound, covalent compound formed by sharing of electron and ionic compound formed by complete transfer of electron. Therefore, the correct option is option D.
What is chemical Compound?Chemical Compound is a combination of molecule, Molecule forms by combination of element and element forms by combination of atoms in fixed proportion.
An ionic compound is a metal and nonmetal combined compound. Ionic compound are very hard. They have high melting and boiling point because of strong ion bond.
Covalent compounds are formed between elements whose electronegativity difference is not very high. Covalent compounds are soft, these compounds have low melting and boiling point. The given compound is C₃H6.
Therefore, the correct option is option D.
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Select all of the Earth Systems that contain carbon.
Oa Atmosphere
Ob Geosphere
Oc Biosphere
Od Hydrosphere
Answer:
a, c, d
Explanation:
biosphere atmosphere hydrosphere lithosphere
Choose all true statements about the water molecule: Choose all true statements about the water molecule: Bonding between the oxygen and hydrogen within the molecule happens due to hydrogen bonding. Water is a permanent electric dipole, having permanent charge separation. Water is not naturally polarized, and gets polarized only due to external electric forces.
Answer: Water is a permanent electric dipole, having permanent charge separation.
Explanation:
Hydrogen bonding is an intermolecular force having partial ionic-covalent character.
In [tex]H_2O[/tex], O is a highly electronegative atom attached to a H atom through a covalent bond. The oxygen atoms being more electronegative gets partial negative charge and H atom gets partial positive charge. Thus water is permanent electric dipole.
Hydrogen bonding takes place between a hydrogen atom (attached with an electronegative atom O) and an electronegative atom (O).
The true statement about water molecules are Bonding between the oxygen and hydrogen within the molecule happens due to hydrogen bonding and water is a permanent electric dipole, having permanent charge separation.
What are hydrogen bonds?Hydrogen bonds is a kind of attraction force which is present between the more electronegative atom and hydrogen atom.
In water molecule, 2 hydrogen atoms and one oxygen atom is present and between the more electronegative oxygen atom and hydrogen atom, hydrogen bond is present.And due to electronegative nature of oxygen atom, they withdraw all the electron density of the bond towards itself as a result of which it possesses permanent electric dipole. Because partial negative charge is present on oxygen atom and partial positive charge is present on the hydrogen atom.Hence options (1) and (2) are correct.
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Practically: Add 1.66 ml of my 0.3M lemonade to a 15 ml microcentrifuge tube. Add 3.33 ml of your diluent (water, in this case) to bring your volume up to 5 ml. Mix your solution either by vortexing or by pipetting up and down with your pipetteman. Let's make sure you got this concept by answering a question below. I have made 15 ml of 200 mM CaCl2 stock and need to make 40 ml of 50mM for my experiment. How much of my concentrated stock solution (in milliliters) and how much water do I need to mix to make the 40 ml of 50mM CaCl2
Answer:
We would need 10 mL of the concentrated CaCl₂ stock solution, and 30 mL of water.
Explanation:
To solve the question asked we can use the C₁V₁=C₂V₂ equation, where:
C₁ = 200 mMV₁ = ?C₂ = 50 mMV₂ = 40 mLWe solve for V₁:
V₁ = 10 mLWe would need 10 mL of the concentrated CaCl₂ stock solution, and (40-10) 30 mL of water.
What is it called when a plant bends in a response to light
An
In phototropism a plant bends or grows directionally in response to light. Shoots usually move towards the light; roots usually move away from it.
Explanation:
Hope This Helps
_______ is the measure of how much water vapor is in the air
Answer:
Humidity is the measure of how much water vapor is in the air.
Landon is investigating the coastal area near where he lives. He has found that one end of the coastal area without barrier islands is losing beach area, but the other end that is bordered with barrier islands has a beach area that has remained the same size. Why is the size of the beach decreasing on the end without barrier islands?
Answer:
Explanation:
Barrier Islands act just as the name states, they are barriers that protect the beaches. They exist to absorb the majority of the external energies that waves, hurricanes, storms, etc. Without it, the beaches begin to become absorbed by the ocean, due to the destructive energy these factors apply, as well as eroding away all rocks into the ocean. This is mainly why the beach with a barrier island is completely protected while the one without a barrier island is decreasing in size.
Island barriers grow near the continent protecting the coasts from erosive factors. The beach with no islands decreases in size because there are no physical limitations that protect the continent from erosion.
------------------------
Barrier islands are deposition of material -sand or any other substrate- that lay on a rocky surface. They get formed near the continent, parallel to the coasts. They play a significant role in avoiding the erosion process.
These islands receive the direct impact of storms, winds, and waves action. Their shape is very dynamic, being constantly modeled by these erosive factors.
These barriers protect the continent from winds, waves, tides, streams, storms, hurricanes, and any other meteorological event that might cause erosion and destruction.
They absorb the energy produced by erosive factors. They also provide a protected area behind them that allows the formation of estuaries and swamps.
A wide diversity of species inhabit these islands, becoming significant spots to protect their biodiversity.
The beach is decreasing on the end without the barrier islands because there is no physical limitations that can protect the continent from the action of waves, tides, and winds, among others. The coasts get eroded, and the beach gets smaller.
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What is the molar mass of C3N4? (Do NOT round this number.)
Answer:
92.06 g/mol
Explanation:
The current temperature in Atlanta, Georgia is 24°C. What is this temperature in Kelvin?
Answer:
297.15kelvin is the correct answer
Answer:297 k
Explanation:
Elements with the same number of electron shells are in the same
Answer:
Elements with the same number of electrons in their outermost shell show similar chemical properties. Example 1: Fluorine, chlorine, bromine, and iodine each have 7 electrons in their outermost shell. These so-called halogens are also quite similar in their chemical behavior.