Sofia goes on a hike on a trail that is 10 km long. She starts at 2:00pm and ends at
5:00pm. The end of the trail is 300m north of the beginning of the trail. What is
Sofia's average velocity?
(Velocity= displacement/time)
100 m/hr S
30 m/hrs
0.01 m/hrs
3.3 m/hr s

Answer:

C

Explanation:

I hope this is correct and have a great day

Answer:

b. upper mantle

Explanation:

low velocity zone of the upper mantle

Answer:

WHat did u mean?

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.

Answer:

297.15kelvin is the correct answer

Answer:297 k

Explanation:

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

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

Answer:

92.06 g/mol

Explanation:

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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Answer:

a, c, d

Explanation:

biosphere atmosphere hydrosphere lithosphere

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

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:

We solve for V₁:

We would need 10 mL of the concentrated CaCl₂ stock solution, and (40-10) 30 mL of water.

Answer:

6.5

Explanation:

half of 5 is 2.5, half of 8 is 4. 2.5+4=6.5

:)

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.

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.

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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Answer:

The average reaction rate is how quickly the reaction proceeds at a specific time. An instantaneous reaction rate is how quickly the reaction proceeds over time.

Explanation:

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.

Hydrogen bonds is a kind of attraction force which is present between the more electronegative atom and hydrogen atom.

Hence options (1) and (2) are correct.

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Answer:

Humidity is the measure of how much water vapor is in the air.

Answer:

X-rays, to check for broken bones in the body.

gamma rays kill cancerous cells

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.

Answer:

Answer should be D. Scientists ignore their own person feelings and interpret data objectively.

Answer:

The removal of one chlorine atom and addition of one fluorine atom.

Explanation:

When GeCl4 is transformed into GeCl3F by a substitution process, the main change that is occur in GeCl4 is the removal of one chlorine atom and addition of one fluorine atom. This process is known as substitution process in which two molecules exchange their atoms with each other when they comes in physically contact with each other.

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.

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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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) =

Answer:

CuCl₂·4H₂O

Explanation:

First we calculate the moles of copper (II) ion in the solution, using the given volume and concentration:

For each Cu⁺² mol there's also one CuCl₂ mol.

We convert 0.01 CuCl₂ moles into grams, using its molar mass:

That 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:

There are four times as many H₂O moles as there are CuCl₂ moles. This means the formula is CuCl₂·4H₂O

Answer:

Explanation:

In this case, we can do this by thinking a little.

Both ways use a grignard reagent, the difference between both ways is that one use an electrophile ketone with a low molecular mass, and the other has a high molecular mass.

The grignard reagent is commonly used to reduce carbonyle groups to alcohols. In the first step, a complex with the reagent is formed in the carbonile, and in the second step, the oxygen atom is hidrated in acid or basic medium and form the respective alcohol.

For the first way, we will use a high molecular mass ketone. In this case the 2-pentanone reacting with CH₃MgBr as a grignard reagent.

For the second way, we will use a low molecular mass ketone, in this case Acetone, reacting with CH₃CH₂CH₂MgBr. Both of them, will give the same product of 2 methyl-2-pentanol. See picture below for that

Hope this helps

Answer:

a rolling ball

Explanation:

kinetic energy is movement energy