Please help me, it’s my last try

Answer:

c. NO2

b. NH3

d. SO4 ^2 -

a. HPO4 ^ 2 -

Explanation:

Acid is a compound which ionizes to produce hydrogen ions. The Ph value for acid is below 7. Base is a compound which ionizes to produce hydroxide ions.  The Ph value for base is above 7. The Conjugate base accepts a proton or releases a hydrogen ion.

Solution :

The equation is :

[tex]$HA (aq) + NaOH(aq) \rightleftharpoons NaA(aq) + H_2O(l)$[/tex]

The number of the moles of HA os 0.00285, and the volume is 25 mL.

15 mL of the 0.0950 M NaOH is added.

The total volume of a solution is V = 25 mL + 15  mL = 40 mL

The pH of the solution is 6.50

Calculating the [tex]K_a[/tex] of HA

[tex]$HA(aq) \rightleftharpoons A^-(aq)+H^+$[/tex]

[tex]K_a=\frac{[A^-].[H^+]}{[HA]}[/tex]

Let s calculate the concentration of HA and NaOH

[tex]$[HA] = \frac{^nH_A}{V}$[/tex]

        [tex]$=\frac{0.00285 \ mol}{0.04 \ L}$[/tex]

       = 0.07125 M

[tex]$[NaOH]= \frac{0.015L \times 0.0950 M}{V}$[/tex]

            [tex]$=\frac{0.001425 mol}{0.04L}$[/tex]

           = 0.0356 M

                                      [tex]$HA(aq) \ \ + \ \ NaOH(aq) \ \ \rightleftharpoons NaA(aq) \\ + \ \ H_2O(aq)$[/tex]

Initial conc. (M)            0.07125 M       0.0356 M            0 M

Change in conc. (M)   -0.0356 M       -0.0356 M        + 0.0356 M

Equilibrium conc. (M)   0.03565 M        0 M                0.0356 M

Therefore, the concentration of HA and the NaA at the equilibrium are [HA] = 0.03565 M and [NaA]= 0.0356 M

0.0356 M of NaA dissociates completely into 0.0356 M [tex]Na^+[/tex] and 0.0356 M [tex]A^-[/tex]

Now for [tex][H^+][/tex]

[tex]$[H^+] = 10^{-pH}$[/tex]

       [tex]$=10^{-6.5}$[/tex]

       [tex]$=3.16 \times 10^{-7}$[/tex]

Calculating the value of [tex]K_a[/tex],

[tex]K_a=\frac{[A^-].[H^+]}{[HA]}[/tex]

     [tex]$=\frac{0.0356 \times 3.16 \times 10^{-7}}{0.03565}$[/tex]

     [tex]$=3.16\times 10^{-7}$[/tex]

Therefore the the value of [tex]K_a[/tex] for the unknown acid is [tex]$3.16\times 10^{-7}$[/tex].

Answer: Rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] >  [tex]CBr_{3}COOH[/tex] >  [tex]CH_{3}COOH[/tex].

Explanation:

More readily a substance is able to donate a hydrogen ion more will be its acidic strength. Hence, stronger will be the acid.

More is the electronegativity of atoms attached to the acid more easily it will donate a proton. Hence, more will be its acidic strength.

Chlorine is more electronegative in nature as compared to bromine. So,

[tex]CCl_{3}COOH[/tex] is more acidic than [tex]CBr_{3}COOH[/tex].

Since there is no electronegative group attached to [tex]CH_{3}COOH[/tex] so it is least acidic than [tex]CCl_{3}COOH[/tex] and [tex]CBr_{3}COOH[/tex].

Thus, we can conclude that rank in order the strongest to the weakest acid is [tex]CCl_{3}COOH[/tex] >  [tex]CBr_{3}COOH[/tex] >  [tex]CH_{3}COOH[/tex].

Answer:

Y = 92.5 %

Explanation:

Hello there!

In this case, since the reaction between lead (II) nitrate and potassium bromide is:

[tex]Pb(NO_3)_2+2KBr\rightarrow PbBr_2+2KNO_3[/tex]

Exhibits a 1:2 mole ratio of the former to the later, we can calculate the moles of lead (II) bromide product to figure out the limiting reactant:

[tex]0.125L*0.150\frac{molPb(NO_3)_2}{L} *\frac{1molPbBr_2}{1molPb(NO_3)_2} =0.01875molPbBr_2\\\\0.145L*0.200\frac{molKBr}{L} *\frac{1molPbBr_2}{2molKBr} =0.0145molPbBr_2[/tex]

Thus, the limiting reactant is the KBr as it yields the fewest moles of PbBr2 product. Afterwards, we calculate the mass of product by using its molar mass:

[tex]0.0145molPbBr_2*\frac{367.01gPbBr_2}{1molPbBr_2} =5.32gPbBr_2[/tex]

And the resulting percent yield:

[tex]Y=\frac{4.92g}{5.32g} *100\%\\\\Y=92.5\%[/tex]

Regards!

Answer:

B porque si :) y eso Jsksjs

Answer:A

Because it's an amino acid and all amino acids are key to any part of your body.

Answer:

A functional group in organic chemistry is an atom or group of atoms that is responsible for the specific properties of an organic compound. Some examples of functional groups include alcohols, alkyl halides, ethers, aldehydes, ketones, amines, carboxylic acids, and esters.

Functional groups also play an important part in organic compound nomenclature; combining the names of the functional groups with the names of the parent organic compounds provides a way to distinguish compounds.

The atoms of a functional group are linked together and to the rest of the compound by covalent bonds. The first carbon atom that attaches to the functional group is referred to as the alpha carbon; the second, the beta carbon; the third, the gamma carbon, etc. Similarly, a functional group can be referred to as primary, secondary, or tertiary, depending on if it is attached to one, two, or three carbon atoms.  

Answer: The instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]

Explanation:

From the graph,

Initial rate of the [tex]Br_2[/tex] = 1.0 M

Time when the concentration of [tex]Br_2[/tex] is 0.5 M (half the concentration ) = 60 sec

For first order reaction:

Calculating rate constant for first order reaction using half life:

[tex]t_{1/2}=\frac{0.693}{k}[/tex] .....(1)

[tex]t_{1/2}[/tex] = half life period = 60 s

k = rate constant = ?

Putting values in equation 1:

[tex]k=\frac{0.693}{60s}\\\\k=0.01155s^{-1}[/tex]

For the given chemical reaction:

[tex]H_2(g)+Br_2(g)\rightarrow 2HBr(g)[/tex]

Rate of the reaction = [tex]-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]

Negative sign represents the disappearance of the reactants

From the above expression:

[tex]k[Br_2]=-\frac{\Delta [Br_2]}{\Delta t}=\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}[/tex]

At 50 seconds, [tex][Br_2]=0.6 M[/tex]

Plugging values in above expression, we get:

[tex]\frac{1}{2}\frac{\Delta [HBr]}{\Delta t}=0.01155\times 0.6\\\\\frac{\Delta [HBr]}{\Delta t}=2\times 0.01155\times 0.6=0.01386=1.4\times 10^{-2}M/s[/tex]

Hence, the instantaneous rate of formation of HBr at 50 s is [tex]1.4\times 10^{-2}M/s[/tex]

Answer:

D

Explanation:

because product are at the top and reactant are at the bottom also it to the power of the moles in front e.g 2NO it will be to the power of 2 in this case.

hope it make sense :)

Answer:

I think A should be the answer because oxygen is the chemical change of carbon.

Answer:

17.48

Explanation:

mass=density×volume

= 0.713g/ml × 24.5 ml

= 17.4685

≈ 17.47

Answer

• Silver

• copper

3

And then for Fe it should be 4 and for the products it should be 2!!

Answer:

NH3 is the base and NH4Cl is the salt.

Explanation:

Hello there!

In this case, according to the given information, it is possible for us to rewrite the chemical equation and thus obtain:

[tex]NH_3+HCl\rightarrow NH_4Cl[/tex]

Whereas it is possible to notice that ammonia, NH3, received the hydrogen ions from HCl to form NH4 ions and Cl ions; in such a way, we infer that NH3 is the base and NH4Cl is the salt.

Regards!

Answer:

NH3 is the base and NH4Cl is the salt

Explanation:

Answer:

See explanation

Explanation:

Number of moles of Copper sulphate = 0.18 M × 6.5/1000= 1.17 × 10^-3 moles of CuSO4

From;

number of moles = mass/molar mass

Molar mass of copper II sulphate = 160g/mol

1.17 × 10^-3 moles = mass/160g/mol

Mass = 1.17 × 10^-3 moles ×160

Mass = 0.187 g

If 1 mole contains 6.02 × 10^23 molecules

1.17 × 10^-3 moles contains 1.17 × 10^-3 moles × 6.02 × 10^23/1 = 7 × 10^20 molecules

From;

C1 V1=C2 V2

0.18 × 6.5 =C2 × 10.5

C2 = 0.18 × 6.5/10.5

C2=0.11 M

CuSO4(aq) + 2NaOH(aq) ----> Cu(OH)2(s) + Na2SO4(aq)

1 mole of CuSO4 yields 1 mole of Cu(OH)2

1.17 × 10^-3 moles of CuSO4 yields 1.17 × 10^-3 moles of Cu(OH)2

Mass of Cu(OH)2 = 1.17 × 10^-3 moles × 98g/mol= 0.11g of Cu(OH)2

Answer: This is the hue of mercury if you're looking for it. Mercury reacts with sulphur to generate a crimson hue. In the past, they always used a thermometer.

Explanation:  However, due of its toxicity, individuals have switched to using alcohol in glass thermometers, which work similarly to mercury thermometers.

hope this helped best of luck mate! :) if this helped make sure to mark me Brainliest!

Answer:

Mass of mercury produced = 2.00 g

Explanation:

At room temperature and pressure, the temperature T = 25° C or 298.15 K while the pressure = 1 atmosphere or 760 mmHg.

Mass of oxide of mercury decomposed at room temperature and pressure = 2.16 g

Volume of oxygen produced = 120 cm³ or 0.12 dm³

One mole of any gas has a volume of 24 dm³ at room temperature and pressure.

Therefore, number of moles of oxygen produced = 0.12 dm³ / 24 dm³/mol = 0.005 moles

Mass of oxygen produced = number of moles × molar mass

Molar mass of oxygen = 32 g/mol

Mass of oxygen produced = 0.005 moles × 32 g/mol = 0.16 g

Thus, mass of mercury produced = mass of mercury oxide decomposed - mass of oxygen produced

Mass of mercury produced = 2.16 g - 0.16 g

Mass of mercury produced = 2.00 g

Answer:

The concentration of the acid, HCl is 0.013 M

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

2HCl + Ca(OH)₂ —> CaCl₂ + 2H₂O

From the balanced equation above,

The mole ratio of the acid, HCl (nₐ) = 2

The mole ratio of base, Ca(OH)₂ (n₆) = 1

Finally, we shall determine the molarity of the HCl. This can be obtained as follow:

Volume of acid, HCl (Vₐ) = 250 mL

Molarity of base, Ca(OH)₂ (M₆) = 0.118 M

Volume of base, Ca(OH)₂ (V₆) = 13.7 mL

Molarity of acid, HCl (Mₐ) =?

MₐVₐ / M₆V₆ = nₐ/n₆

Mₐ × 250 / 0.118 × 13.7 = 2/1

Mₐ × 250 / 1.6166 = 2

Cross multiply

Mₐ × 250 = 1.6166 × 2

Mₐ × 250 = 3.2332

Divide both side by side 250

Mₐ = 3.2332 / 250

Mₐ = 0.013 M

Thus, the concentration of the acid, HCl is 0.013 M

Answer:

There isn't enough information to answer you're question.

Explanation:

Have a great day!!!

Answer:

It determines how difficult it is to start the reaction.

Explanation:

The more finely divided the solid is, the faster the reaction happens. A powdered solid will normally produce faster reaction than if the same mass is present as a single lump. The powdered solid has a greater surface than the single lump

Explanation:

Mark as brainlist

Answer:

% yield =  82.5%

Explanation:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

Our reactants are:

Our products are:

We do not have information about moles of reactants, but we do know the theoretical yield and the grams of product, in this case Cl₂O, we have produced.

Percent yield = (Yield produced / Theoretical yield) . 100

Theoretical yield is the mass of product which is produced by sufficent reactant. We replace data:

% yield = (0.71 g/0.86g) . 100 = 82.5%

The percent % yield =  82.5%

The balanced chemical equation will be:

HgO + 2Cl₂ →  HgCl₂ +  Cl₂O

The reactants participating in this reaction are: HgO and Cl₂

The products so formed are: HgCl₂ +  Cl₂O

[tex]\text{ Percent yield} = \frac{\text{Yield produced}}{\text{Theoretical yield}} *100[/tex]

The theoretical yield is the maximum possible mass of a product that can be made in a chemical reaction.

[tex]\text{Percent yield}= \frac{0.71 g}{0.86g} * 100 \\\\\text{Percent yield}= 82.5\%[/tex]

Thus, the percent yield is 82.5%.

Learn more:

brainly.com/question/25996347

Answer:

36g

Explanation:

you need to know the equation mass=moles*mr (in this case mr of carbon which is 12)

so 3*12=36g

hope this helps :)

Answer:

18%.0

Explanation:

hipe it helps

pa brainlist

Answer:

-1.6 × 10⁻⁹ z

Explanation:

To attempt this type of question, we need to first divide each charge present in the question with the smallest one.

i.e.

[tex]A = \dfrac{-4.8 \times 10^{-9}}{-4.8 \times 10^{-9}}= 1[/tex]

[tex]B = \dfrac{-9.6 \times 10^{-9}}{-4.8 \times 10^{-9}}= 2[/tex]

[tex]C= \dfrac{-6.4 \times 10^{-9}}{-4.8 \times 10^{-9}}= 1.33[/tex]

[tex]D= \dfrac{-12.8 \times 10^{-9}}{-4.8 \times 10^{-9}}= 2.67 \simeq 3[/tex]

The next thing to do is to multiply each obtained value with the highest integer

A = 1 × 3 = 3

B = 2 × 3 = 6

C = 1.33 × 3 = 3.99

D = 3 × 3 = 9

Finally, we divide each charge by the result from above.

[tex]A = \dfrac{-4.8 \times 10^{-9}}{3}= -1.6 \times 10^{-9}[/tex]

[tex]B = \dfrac{-9.6 \times 10^{-9}}{6}= -1.6\times 10^{-9}[/tex]

[tex]C= \dfrac{-6.4 \times 10^{-9}}{3.99}= -1.6\times 10^{-9}[/tex]

Thus, we can therefore easily conclude that the charge in zorgs (z) is:

-1.6 × 10⁻⁹ z

Answer:

be is the answer to your question

Answer:

CuCl2 (aq) + 2 KOH (aq) → Cu(OH)2 (s) + 2 KCl (aq)

Explanation:

I did it.

Answer:

CuCl2 + 2KOH------------------>Cu(OH)2 + 2KCl

Explanation:

this is the right solution of equation

Answer:

D) doubles the rate

Explanation:

The given reaction is :

[tex]$CH_3Br + OH^- \rightarrow CH_3OH+Br^-$[/tex]

For the [tex]SN^2[/tex] reaction, the rate of reaction depends upon the concentration of both the [tex]$\text{alkyl halide}$[/tex] as well as the [tex]\text{nucleophile.}[/tex]

That is the rate = [tex]$k[CH_3Br][OH^-]$[/tex]

Now if the [tex]$[CH_3Br]$[/tex] becomes [tex]$2[CH_3Br]$[/tex], then the rate becomes double.

So the rate' is :

= [tex]$2k[CH_3Br][OH^-]$[/tex]

= 2 x rate

Therefore, the answer is (D) doubles the rate.

Answer:

The correct answer is - hard water reacts to form the calcium or magnesium salt of the organic acid of the soap.

Explanation:

Soaps are made up of fatty acids or oils by treating with strong alkali and are salts of sodium and potassium. Hard water, on the other hand, has a high concentration of minerals in comparison to soft water. When hard water and soap are mixed together the salts of the minerals like Ca2+ and Mg2+ ions present in hard water react with fatty acids of the soap.

The sodium salts are changed to the salts of calcium and magnesium which are precipitated to an insoluble substance. The insoluble salts of the calcium or magnesium dirt stick on the clothes thus cleaning ability of soap is reduced.