I’m stuck on this can I get a little help please

Answer:

7

Explanation:

You divide the 14m/s by 2 and get the answer of the acceleration of 7

Answer:

D H2PO4– + HPO42–

Explanation:

The acid dissociation constant for [tex]\mathbf{H_3PO_4 , H_2PO^{-}_4 , HPO_4^{2-}}[/tex] are [tex]\mathbf{7\times 10^{-3}, \ \ 8\times 10^{-8} ,\ \ 5\times 10^{-13}}[/tex] respectively.

[tex]\mathbf{pka (H_3PO_4) = -log (7\times 10^{-3} )=2.2}[/tex]

[tex]\mathbf{pka (H_2PO_4^-) = -log (8\times 10^{-8} )=7.1}[/tex]

[tex]\mathbf{pka (HPO_4^{2-}) = -log (5\times 10^{-13} )=12.3}[/tex]

The reason while option D is the best answer is that, the value of pKa for both

[tex]\mathbf{H_2PO^{-}_4 ,\ \& \ HPO_4^{2-}}[/tex] lies on either side of the desired pH of the buffer. This implies that one is slightly over and the other is slightly under.

Using Henderson-Hasselbach equation:

[tex]\mathbf{pH = pKa + log \Big( \dfrac{HPO_4^{2-}}{H_2PO_4^-} \Big)}[/tex]

The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex]. Thus, option D is correct.

The buffers are the solutions of acids and base of appropriate pH, that are able to limit the change in pH in the reaction mixture.

The buffer pH is adjusted with the compounds that has been able to add base or acid to the solution.

For the formulation of buffer of specific pH, the acid and base solutions are required.

The compounds that are used for the formulation of the pH 9 buffer are [tex]\rm H_2PO_4^-\;and\;HPO_4^+[/tex], as they are able to provide acid and base to the solution.

Thus, option D is correct.

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Answer:

Bacteria are a type of biological cell. They constitute a large domain of prokaryotic microorganisms

some are good some are bad

Explanation:

Answer:

symbiotic

Explanation:

There like a close friendship

Answer:

Explanation:

2HNO₃ + Ba( OH)₂ = Ba( NO₃ )₂ + 2H₂O .

2 mole      1 mole

13.9 mL of .174M barium hydroxide contains .0139 x .174 moles

= 2.42 x 10⁻³ moles .

1 mole of barium hydroxide reacts with 2 moles of nitric acid

2.42 x 10⁻³ moles of barium hydroxide will react with 2 x 2.42 x 10⁻³ moles of nitric acid

= 4.84 x 10⁻³ moles

4.84 x 10⁻³ moles of nitric acid is contained in 28.7 mL

molarity of nitric acid = 4.84 x 10⁻³ / 28.7 x 10⁻³

= .169 M .

Answer:

Explanation:

From the information given:

[tex]CaF_2 \to Ca^{2+} + 2F^-[/tex]

[tex]Ksp = 3.2 \times 10^{-11}[/tex]

no of moles of [tex]Ca^{2+}[/tex] = 0.01 L × 0.0010 mol/L

no of moles of [tex]Ca^{2+}[/tex] = [tex]1 \times 10^{-5} \ mol[/tex]

no of moles of [tex]F^-[/tex] = 0.01 L × 0.00010 mol/L

no of moles of [tex]F^-[/tex] = [tex]1 \times 10^{-6}\ mol[/tex]

Total volume = 0.02 L

[tex][Ca^{2+}}] = \dfrac{1\times10^{-5} \ mol}{0.02 \ L} \\ \\ \\ \[[Ca^{2+}}] = 0.0005 \ mol/L[/tex]

[tex][F^{-}] = \dfrac{(1\times 10^{-6} \ mol)}{0.02 \ L}[/tex]

[tex][F^{-}] = 5 \times 10^{-5} \ mol/L[/tex]

[tex]Q = [Ca^{2+}][F^-]^2 \\ \\ Q = 0.0005 \times (5\times 10^{-5})^2 \\ \\ Q = 1.25 \times 10^{-12}[/tex]

Since Q<ksp, then there will no be any precipitation of CaF2

Answer:

a) the number-average molecular weight is 32,400 g/mol

b) the weight-average molecular weight is 36,320 g/mol

c) the degree of polymerization is 770

Explanation:

Given the data in the question;

Molecular                  Mean        Number      Weight      Number        Weight

weight                                                                             average         average

(g/mol)                    Mi(g/mol)         xi                wi          xiMi                  wiMi

8,000-16,000            12,000        0.07           0.03         840                360

16,000-24,000          20,000       0.15           0.09         3000              1800

24,000-32,000         28,000       0.26           0.21          7280              5880

32,000-40,000         36,000       0.27           0.27         9720               9720

40,000-48,000         44,000       0.18            0.28         7920              12320

48,000-56,000         52,000       0.07           0.12          3640              6240

∑                                                                                Mn=32,400     Mw=36,320

so;

a)  the number-average molecular weight

Mn = ∑Mixi

so from the table above; summation of Row Mixi

Mn = ∑Mixi = 32,400

Therefore, the number-average molecular weight is 32,400 g/mol

b) the weight-average molecular weight

Mw = ∑Miwi

so from the table above; summation of Row Miwi

Mw = ∑Miwi = 36,320

Therefore, the weight-average molecular weight is 36,320 g/mol

c) the degree of polymerization

the degree of polymerization of polypropylene can be determined using number-average molecular and repeat unit molecular weight.

now, for polypropylene { CH₂ = CH - CH₃ }

the repeat unit consist of 3 carbon atoms and 6 hydrogen atoms

given that;

Atomic weight of Carbon mC = 12.01 g/mol and

Atomic weight of  Hydrogen mH = 1.008 g/mol

now we find the repeat unit molecular weight of polypropylene

m = nCmC + nHmH

where n is the number of repeat of atoms

so we substitute

m = ( 3 × 12.01) + ( 6 × 1.008)

m = 36.03 + 6.048

m = 42.078 g/mol

now we calculate the degree of polymerization;

DP = Mn / m

so we substitute

DP = 32,400 / 42.078

DP = 769.9985 ≈ 770

Therefore,  the degree of polymerization is 770

Answer:

1. Wind speed

2. Wind change

3. Wind elevation

4. Wind direction

Answer:

For k12 its::

Explanation:

wind direction

wind speed

wind fetch

wind duration

Yw guys! ^^

the water will be increased

Answer:

It’s is a simple

Explanation:the prokaryotic cell involves a simple process which intern involves one chromosom

Answer:

Explanation:

Atoms are the building blocks of matter.

They are the smallest particles of an element that still have the element's properties.

All atoms are very small, but atoms of different elements vary in size.

Three main types of particles that make up all atoms are protons, neutrons, and electrons.

Answer:

The algae lose their ability to photosynthesize.

Explanation:

Because the algae turn the energy from the sunlight into chemicals.

Hoped this helped!

Answer: Silver (I) fluoride molecule · AgF

Classification: Inorganic compound (Could be salt)

Ionic compound (Silver is a metal)

Valence of F (F must form an octet): 7

Valence of Ag: 11

Total valence electrons: 18

Molar mass: 126.87 g/mol

Explanation:

Answer:

Differences between Orbit and Orbitals

Orbit

An orbit is the simple planar representation of an electron.

It can be simply defined as the path that gets established in a circular motion by revolving the electron around the nucleus

The shape of molecules cannot be explained by an orbit as they are non-directional by nature.

An orbit that is well-defined goes against the Heisenberg principle.

Orbital

An orbital refers to the dimensional motion of an electron around the nucleus in a three-dimensional motion.

An orbital can simply be defined as the space or the region where the electron is likely to be found the most.

The shapes of the molecules can be found out as they are directional by nature.

An ideal orbital agrees with the theory of Heisenberg’s Principles.

Answer:4m/s

Explanation:The reason why that the answer is because I am Smart.

Answer:

I2(g)/I^-(aq)//H2 (g)/H^+(aq)

Explanation:

Let us remember that in every redox reaction, a specie is oxidized and a specie is reduced.

This means that one specie looses electrons while the other species gains electrons.

Considering the overall reaction; H2 + I2 = 2 HI

Oxidation half equation;

H2 (g) ------> 2H^+(aq) + 2e

Reduction half equation;

I2(g) + 2e ------> 2I^-(aq)

Line notation;

I2(g)/I^-(aq)//H2 (g)/H^+(aq)

Answer:

The average speed must be 30mph so this means the car traveled for 2hrs 60/30

The full question is shown in the image attached to this answer

Answer:

6.2 * 10^-3

Explanation:

The reaction at equilibrium is as follows;

TiCl4(l) → Ti(s)+ 2Cl2(g)

We have to obtain the concentration of chlorine gas as follows;

[Cl2] = 1.08/70.91 g/mol × 5.2 L

[Cl2] = 0.079 M

Kc = [Cl2]^2

Kc = [ 0.079]^2

Kc = 6.2 * 10^-3

Answer:

100. mL

Explanation:

The computation of the volume in mL is shown below:

The balance equation of the double displacement reaction is

[tex]CaCl_{2} + Na_{2}CO_{3} \rightarrow 2 NaCl + CaCO_{3}[/tex]

Now determine the moles that corresponding to 1.00 g of CaCO₃

As,

The molar mass of CaCO₃ is 100.09 g/mol.

So,

= 1.00 g × 1 mol/100.09 g

= 0.0100 mol

Now

the moles of CaCl₂ needed to generate 0.0100 moles of CaCO₃

As we know that

The molar ratio of CaCl₂ to CaCO₃ is 1:1.

So, The moles of CaCl₂ needed is

=  1 ÷ 1 × 0.0100 mol

= 0.0100 mol.

Now volume of 0.100 M CaCl₂ that contains 0.0100 mol is  

= 0.0100 mol × 1 L/0.100 mol × 1000 mL/1 L

= 100. mL

Answer:

NaHCo3+Na2So4---Nna2So4+H2O+CO2

Answer:

sodium two sulphate+Carbondioxed gas +water

Answer:

Both empirical and molecular are C₈H₈O₃.

Explanation:

Hello!

In this case, according the attached picture, it is possible to figure out the molecular formula of the mandelic acid by counting each carbon, hydrogen and oxygen in the molecule.

In such a way, we can see the presence of eight carbon atoms, eight hydrogen atoms and three carbon atoms; thus, the molecular formula is:

C₈H₈O₃

Furthermore, since the empirical formula is the smallest representation of the molecular formula when we are able to simplify it, we evidence no simplification is possible, consequently, the empirical formula equals the molecular one.

Best regards!

Answer:

The percent composition for nitrogen in chromium(III) nitrate is 6%.

Explanation:

The mass percent of nitrogen in chromium(III) nitrate is 17.655%.

Calculation,

Molar mass of one oxygen = 16 g

molar mass of nine oxygen = 9 × 16 g = 144 g

molar mass of one nitrogen atom = 14 g

molar mass of three nitrogen atom = 3 × 14 g = 42 g

molar mass of one chromium atom = 51.99 g

molar mass of chromium (III) nitrate molecule = 144 g + 42 g + 51.99 g = 237.99 g

Mass percent of nitrogen = mass of three nitrogen atom× 100 /mass of chromium(III)nitrate

Mass percent of nitrogen = 42 g/237.99 g × 100 = 17.655%

The percentage of the mass of the element or solute divided by the mass of the compound or solute is called mass percentage

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Answer: A chemical compound can be described as substance composed of atoms from more than one element held together by chemical bonds in a fixed stoichiometric proportion. A compound has different physical and chemical properties from its constituent elements.

For example : compound water is made up of H and O bonded together and it has different properties from O and H.

Thus, among the given options, the one coreectly describing a compound is

a) The atoms are bonded together, and the compound has different physical and chemical properties than the individual elements.

Answer:

8.45 × 10⁻²⁰ g

Explanation:

Step 1: Given data

Step 2: Calculate the mass, in grams, of 1 atom of Fe

We will use Avogadro's number: there are 6.02 × 10²³ atoms of Fe in 1 mole of Fe.

55.85 g/mol × 1 mol/6.02 × 10²³ atom = 9.27 × 10⁻²³ g/atom

Step 3: Calculate the mass corresponding to 912 atoms

9.27 × 10⁻²³ g/atom × 912 atom = 8.45 × 10⁻²⁰ g

Answer: The final concentration of [tex]Cl_2[/tex] at equilibrium is 0.36 M

Explanation:

Moles of  [tex]PCl_5[/tex] = 0.64 mole  

Volume of solution = 1.0 L

Initial concentration of [tex]PCl_5[/tex] = [tex]\frac{moles}{Volume}=\frac{0.64mol}{1.0L}=0.64 M[/tex]

The given balanced equilibrium reaction is,

                     [tex]PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)[/tex]

Initial conc.       0.64 M         0M        0M  

At eqm. conc.     (0.64-x) M   (x) M      (x) M

The expression for equilibrium constant for this reaction will be,

[tex]K_c=\frac{[Cl_2]\times [PCl_3]}{[PCl_5]}[/tex]  

Now put all the given values in this expression, we get

[tex]0.47=\frac{(x)\times (x)}{(0.64-x)}[/tex]

By solving the term 'x', we get :

x = 0.36

Thus, the final concentration of [tex]Cl_2[/tex] at equilibrium is x = 0.36 M

The concentration of Cl2 is 0.36M.

Number of moles of PCl5 = 0.64 mol

Volume =  1.0 L

Concentration of PCl5 = 0.64 mol/1.0 L  = 0.64  M

The equation of the reaction is;

          PCl5 (g)→ PCl3 (aq) + Cl2 (g)

I         0.64            0                0

C       -x                 +x               +x

E     0.64 - x           x                  x

Kc = [PCl3] [Cl2]/[PCl5]

0.47 = x^2/0.64 - x

0.47(0.64 - x) =  x^2

0.3 - 0.47x =x^2

x^2 +  0.47x - 0.3 = 0

x = 0.36 M

The concentration of Cl2 is 0.36M.

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Answer:

FALSE

Explanation:

false. kinematics equations are used for many purposes.it is used to drive equations and to find the motion of an object. but it is used more in physics rather than maths.

Explanation: solids are frozen like if you freeze tea it becomes a solid , liquids is like tea and gases is like when you boil water and it becomes a gas

Answer:

thermal

Explanation:

a p e x

Answer:

[tex]Y=12.2 \frac{gpm}{ft}[/tex]

Explanation:

Hello!

In this case, since we can find that the well produces 280 gpm, and the given drawdown is 23 ft, we need to divide 280 by 23 to obtain the yield in gmp/ft as shown below:

[tex]Y=\frac{280gpm}{23ft} \\\\Y=12.2 \frac{gpm}{ft}[/tex]

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