What orbits around the nucleus

Answer:

The pH of the solution following the addition of 0.075 moles of NaOH is 5.7.

Explanation:

The equation of the buffer solution is the following:

C₄H₇O₂H(aq) + H₂O(l) ⇄ C₄H₇O₂⁻(aq) + H₃O⁺(aq)     (1)    

The pH of the buffer solution can be found using the Henderson-Hasselbalch equation:

[tex] pH = pKa + log(\frac{[NaC_{4}H_{7}O_{2}]}{[C_{4}H_{8}O_{2}]}) [/tex]   (2)

The NaOH added will react with butanoic acid tot produce sodium butanoate:

C₄H₇O₂H(aq) + OH⁻(aq) ⇄ C₄H₇O₂⁻(aq) + H₂O(l)  (3)          

[tex] n_{C_{4}H_{7}O_{2}H}_{i} = C*V = 0.107 M*1.30 L = 0.139 moles [/tex]

[tex] n_{C_{4}H_{7}O_{2}^{-}} = 0.345 M*1.30 L = 0.449 moles [/tex]

[tex] n_{NaOH} = 0.075 moles [/tex]

[tex] n_{C_{4}H_{7}O_{2}H} = 0.139 moles - 0.075 moles = 0.064 moles [/tex]

[tex] n_{C_{4}H_{7}O_{2}^{-}} = 0.449 moles + 0.075 moles = 0.524 moles [/tex]

[tex]C_{C_{4}H_{7}O_{2}H} = \frac{0.064 moles}{1.30 L} = 0.049 M[/tex]

[tex] C_{C_{4}H_{7}O_{2}^{-}} = \frac{0.524 moles}{1.30 L} = 0.403 M [/tex]

Now, from equation (1) we have:

C₄H₇O₂H(aq) + H₂O(l) ⇄ C₄H₇O₂⁻(aq) + H₃O⁺(aq)

0.049 - x                           0.403 + x            x  

[tex] Ka = \frac{[C_{4}H_{7}O_{2}^{-}][H_{3}O^{+}]}{C_{4}H_{7}O_{2}H} [/tex]

[tex]1.52 \cdot 10^{-5} = \frac{(0.403 + x)x}{0.049 - x}[/tex]

[tex]1.52 \cdot 10^{-5}*(0.049 - x) - (0.403 + x)x = 0[/tex]

By solving the above equation for x we have:            

x = 1.85x10⁻⁶ = [H₃O⁺]

So, the concentration of butanoic acid and sodium butanoate is:

[tex][C_{4}H_{7}O_{2}^{-}] = 0.345 + 1.85 \cdot 10^{-6} = 0.345 M[/tex]

[tex][C_{4}H_{7}O_{2}H] = 0.049 - 1.85 \cdot 10^{-6} = 0.049 M[/tex]

Finally, from equation (2) we have:

[tex] pH = pKa + log(\frac{[NaC_{4}H_{7}O_{2}]}{[C_{4}H_{8}O_{2}]}) [/tex]

[tex]pH = -log(1.52 \cdot 10^{-5}) + log(\frac{0.345}{0.049}) = 5.7[/tex]

Therefore, the pH of the solution following the addition of 0.075 moles of NaOH is 5.7.

I hope it helps you!

Answer:

Producer gas and water gas contain carbon monoxide and hydrogen.

The correct answer is D. The native species would not have to  compete for necessary resources

Explanation:

Invasive species, which include any living organism that is not native in an ecosystem, contribute to the extinction of native species as they compete for resources such as food, shelter, etc. with native species. For example, the  Asian Carp, which was introduced to lakes in the U.S. consumes plankton, which reduces the amount of plankton available for native fish. In this context, by removing invasive species native species would not have to compete for resources and their chances to extinct will fall.

Answer:

Alkalai B

Explanation:

B because its a weak alkali ie baking soda ph 8.3(sodium bicarbonate)which is used as a remeady of heartburns and stomach acids.

Answer:

D. A combustion reaction

Explanation:

Answer:

B. Neutral

Explanation:

When there is a ionic bond,  one element steals or takes away an electron from the other element.

An example is NaCl

In this compound, Chlorine atom steals an extra electron from Sodium to fill its outer shell. So, this is a Ionic bond. Since, the Sodium compound gives away an atom, it is positively charged. Since, Chlorine steals an atom, it is negatively charged. Opposite charges attract, so they become a compound.

When positive and negative mix, it becomes neutral.

Answer:

Scientific literacy and critical thinking skills will nullify the claims made in the advertisement.

Explanation:

The claims made in the advertisement contradict the scientific laws and the person who understands the scientific theories can easily understand that. Critical thinkers may derive rational insights from a collection of facts, and distinguish between relevant and less important reasons for problem-solving or decision making. Therefore on objectively evaluating scientific theories, we conclude to a rational decision, that is the claims are false.

Answer:

Chlorine has strong inter molecular forces than iodine

Explanation:

Answer:

Chlorine has strong inter molecular forces than iodine

Explanation:

I2 is a solid while Cl2 is a gas because Iodine molecules are larger and therefore experience stronger intermolecular forces.

HOPE IT HELPS :)

PLEASE MARK IT THE BRAINLIEST!

Answer:

it's option D

Answer:

The correct answer is 15.54 kJ per degree C.

Explanation:

The enthalpy change for one mole of a substance, which combines or burns with the oxygen under the standard conditions, that is, at 25 degree C and 1 bar pressure is known as the standard molar enthalpy of combustion. The amount of heat transferred can be calculated by using the formula, q = mcΔT -------------(i)

Here q is the amount of heat transferred, c is the specific heat, ΔT is the change in temperature, and m is the mass of the substance. As in case of bomb calorimeter, mass if considered constant, thus, for calorimeter the equation mentioned will become, q = cΔT ---- (ii)

The standard molar enthalpy of combustion for carbon is -393.5 kJ/mol, that is, -393.5 kJ per mole of heat is generated by burning one mole of carbon. The molecular mass of carbon is 12 gram per mole.  

Thus, the number of moles of carbon equivalent to 0.562 grams of carbon can be determined as,  

Number of moles of carbon = mass / molecular mas

= 0.562 grams / 12 gram per mole

= 0.047 mol

The heat generated by burning 0.562 grams or 0.047 mole will be,  

q = ΔH° × number of moles

= (-393.51 kJ/mol) × 0.047 mol

= -18.49 kJ, the negative sign shows that the heat is produced.  

To find heat capacity of calorimeter, put the value of q as -18.49 kJ, for ΔT as (27.93 °C - 26.74 °C) in the equation (ii)

18.49 kJ = c × (27.93 - 26.74)

c = 18.49 kJ/1.19 °C

c = 15.54 kJ/°C

Answer:

2N2 + 5O2 => 2N2O5

4Fe + 3O2 => 2 Fe2O3

H2 + Cl2 => 2 HCl

Answer

Explanation:

Answer:

The answer is "Option B"

Explanation:

From the query, the following knowledge is derived:  

Yield in percentage = 47%  

Performance of theory = 4860 g  

Actual yield Rate =?  

The percentage return is defined simply by the ratio between both the real return as well as the conceptual return multiplied by the 100. It's also represented as numerically:

[tex]Rate = \frac{Existing \ Rate} {Theoretical \ Rate} \times 100[/tex]

Now We can obtain the percent yield as followed using the above formula:  

[tex]\text{Yield in percentage}= \frac{Actual \ yield \ Rate} {Theorical \ Rate} \times 100[/tex]

[tex]47\% = \frac{Actual \ yield \ Rate}{4860}[/tex]

The value of the Actual yield Rate =[tex]47\% \times 4860[/tex]

                                                        [tex]= \frac{47}{100} \times 4860 \\\\ = 2284.2 g[/tex]

The Actual yield Rate= 2284.2 g.

Answer:

20 mL

Explanation:

The student should record 20 mL as the correct volume.

The curved surface of a liquid that is usually observed in a buret is referred to as the meniscus. This meniscus is created as a result of the surface tension of the liquid against the walls of the buret. Hence, in order to avoid errors due to parallax, the bottom of the meniscus should be read and not the top.

Therefore, the correct volume that the student should record is 20 mL.

Answer:

Virus is living due to reproduction and non-living due to crystal appearance.

Explanation:

Characteristics that viruses display is the ability of reproduction in which they increase in population which is a living character and have DNA or RNA which help them to make exact copies of itself. Virus is parasitic in nature because it causes harm to the living host such as humans, animals and plants. Some characteristics that viruses don't display are that they are not like living cells, have no membrane around them, no organelles such as mitochondria, golgi bodies, endoplasmic reticulum and lysosomes etc. Viruses are present in crystal form outside the cell.

Answer:

Explanation:

a )

Zn = Zn²⁺ + 2e   ( oxidation reaction )

Fe³⁺ + 3e = Fe( s ) ( reduction reaction )

b )

[ Zn = Zn²⁺ + 2e ] x 3

[ Fe³⁺ + 3e = Fe( s ) ] x 2

-------------------------------------------------------------------

3 Zn + 2 Fe³⁺ + 6e = 3 Zn²⁺ + 2 Fe ( s ) + 6e

3 Zn + 2 Fe³⁺  = 3 Zn²⁺ + 2 Fe ( s )

Answer:

I believe it's A) an array of positive ions in a sea of electrons

Answer:

The answer is 97.2g .

Explanation:

Given that 1 mL is equals to 1 cm². Then we have to apply Density formula :

[tex]density = \frac{mass}{volume} [/tex]

[tex]let \: density = 2.7 \: , \: volume = 36[/tex]

[tex]2.7 = \frac{mass}{36} [/tex]

[tex]mass = 2.7 \times 36[/tex]

[tex]mass = 97.2 \: grams[/tex]

Answer:

The answer is

555.94g

Explanation:

To find the mass of a substance given it's density and volume we use the formula

Making mass the subject we have

mass = Density × volume

From the question

Density = 7.7 g/cm³

Volume = 72.2 cm³

Substitute the values into the above formula

That's

mass = 7.7 g/cm³ × 72.2 cm³

We have the final answer as

Hope this helps you

Answer:

[tex]\huge\boxed{94.9\ grams}[/tex]

Explanation:

Relative formula mass of phosphate:

=> [tex]PO_{4}[/tex]  [Ignoring the charge on it]

Atomic mass of P = 31.0 grams, O = 15.9 grams

=>  30.97 + 4(15.9)

=> 30.97 + 63.9

=> 94.87

≈ 94.9 grams [To nearest tenth]

Answer:

[tex]\huge \boxed{\mathrm{D. \ 94.9 \ grams}}[/tex]

Explanation:

Phosphate chemical formula is given as,

[tex]\sf PO_4[/tex]

There is one phosphorus atom and four oxygen atoms.

Atomic mass of Phosphorus [tex]\sf P[/tex] = 30.974 grams

Atomic mass of Oxygen [tex]\sf O[/tex] = 15.999 grams

[tex]\Rightarrow 30.974 + 4(15.999)[/tex]

[tex]\Rightarrow 30.974+ 63.996[/tex]

[tex]\Rightarrow 94.97[/tex]

The relative formula mass of phosphate [tex]\sf PO_4[/tex] is 94.9 grams.

Answer:

The average mass of the gold coin reported to five significant figures, even though you  had to divide by "3" to obtain the average.

Explanation:

Given that,

The mass of a silver liberty was measured three times and each measurement was made  to five digits.

The mass values are,

[tex]m_{1}=12.519\ g[/tex]

[tex]m_{2}=12.521\ g[/tex]

[tex]m_{3}=12.496\ g[/tex]

The average mass of the gold  coin is 12.512 g.

We know that,

Significant figures :

Significant figures is explained the nonzero, leading zero and zeros between two nonzero digits.

For example,

The digits is 0.003405

In the digit, 345 = nonzero

0.00 = leading zero

The average mass of the gold coin reported to five significant figures because average mass is 12,512. All digits are nonzero.

Nonzero digit are significant.

Hence, The average mass of the gold coin reported to five significant figures, even though you  had to divide by "3" to obtain the average.

Answer:

Explanation:

given mass on earth =98 kg

gravitational pull on mars =3.711 m/s2

gravitational pull on venus =8.87 m/s2

weight of the body on mars =weight on earth/9.81 m/s2 *3.711 m/s2

W=98 kg*3.711 /9.81m/s2

W=37.07 kg

weight on the venus =weight on earth*8.87 m/s2 /9.81 m/s2

W= 98 kg*7.87 m/s2/9.81 m/s2

W=78.62 kg

Answer:

[tex]7.589\times 10^{2}[/tex]

Explanation:

The expression can be solved mathematically as follows:

1) [tex]8.310\times 10^{2}-7.210\times 10^{1}[/tex] Given

2) [tex]8.310\times 10^{1+1} - 7.210\times 10^{1}[/tex] Definition of sum

3) [tex](8.310\times 10^{1})\times 10^{1}-7.210\times 10^{1}[/tex] [tex]a^{m+n} = a^{m}\cdot a^{n}[/tex]/Associative property

4) [tex](8.310\times 10^{1}-7.210)\times 10^{1}[/tex] Distributive property

5) [tex](83.100-7.210)\times 10^{1}[/tex] Multiplication

6) [tex]75.89\times 10^{1}[/tex] Subtraction.

7) [tex](7.589\times 10^{1})\times 10^{1}[/tex] Multiplication/Associative property

8) [tex]7.589\times (10^{1}\times 10^{1})[/tex] Associative property

9) [tex]7.589\times 10^{2}[/tex] [tex]a^{m+n} = a^{m}\cdot a^{n}[/tex]/Result

Answer:

1: exothermic

2:hydrated iron (III) oxide

3:reactants

4:precipitate

5: hydrogen gas

Answer:1.exothermic

2.hydrated iron (III) oxide

3.reactants

4.precipitate

5. hydrogen gas

Answer:

hydrant flying with balloon, balloon has lithp letting air out, bee: really yum balloon

    =                           =                                 =                                   =

hydrogen              helium                     lithium                     beryllium

be bore on the balloon, balloon pops, hydrant drops and makes a car bomb

           =                                                                                                  =

    boron                                                                                              carbon

night row general gets hurt by car bomb nearby, that general gets off boat

        =                                

nitrogen

wearing oxygen mask, mask is full of fluride gel, then he got neon teeth

             =                                               =                                      =

         oxygen                                fluorine                                neon

(try making a story out of the elements, use your imagenation)

I will give u tips to learn whole periodic table

1. Break down the table into sections

2. Spread out the memorisation process

3. Learn the elements in a song

4. Make none sense words made from element symbols

5. Use colour to learn element groups

6. Use mnemonic device to help remember the order of elements

I am sure this will be helpful for uuu

Explanation:

Answer:

Below is the clarification of that same particular question.

Explanation:

For that kind of weak diprotic predictor, the standard economic statement can indeed be published as:

    ⇒  [tex]H_2In_(aq)\rightleftharpoons In^{2-} +2H^+[/tex]

Answer:

Total gram of Ca = 99.26 g

Explanation:

Given:

Mass of CaCl₂ = 277.45 g

Find:

Mass of Ca

Computation:

Ca = 40 g/mol

Cl₂ = 2 (35.5) g/mol = 71 g/mol

Total CaCl₂ = 111 g/mol

Total gram of Ca = [40 / 111] 277.45 g

Total gram of Ca = 99.26 g