PLEASE HELP WHAT IS THE RIGHT ANSWER

Answer:

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.32 ) = 6.32

Explanation:

Given 4.3 x 10⁻⁷M H₂CO₃ (Ka1 = 4.2 x 10⁻⁷ &  Ka2 = 4.8 x 10⁻¹¹)

Note: The Ka2 value for the 2nd ionization step is so small (Ka2 = 4.8 x 10⁻¹¹) It will be assumed all of the hydronium ions (H⁺) come from the 1st ionization step.  

1st Ionization step

                    H₂CO₃        ⇄   H⁺ + HCO₃⁻

C(initial)     4.3 x 10⁻⁷             0         0

ΔC                   -x                  +x        +x

C(final)      4.3 x 10⁻⁷ - x         x          x

Note: the 'x' value in this analysis can not be dropped as the Conc/Ka value is less than 10². In this case he C/Ka ratio* (4.3E-7/4.2E-7 ≈ 1)  is far below 10².

So, one sets up the equilibrium equation to be quadric and the x-value can be determined.

Ka1 = [H⁺][HSO⁻]/[H₂SO₃] = (x)(x)/(4.3 x 10⁻ - x) = x²/(4.3 x 10⁻⁷ - x) = 4.2 x 10⁻⁷

=>   x² = 4.2 x 10⁻⁷(4.3 x 10⁻⁷ - x)

=>   x² + 4.2 x 10⁻⁷x - 1.8 x 10⁻¹³ = 0              

      a = 1, b = 4.2 x 10⁻⁷, c = - 1.8 x 10⁻¹³

x = b² ± SqrRt(b² - 4(1)(-1.8 x 10⁻¹³ / 2(1) =  4.75 x 10⁻⁷

x = [H⁺] = 4.75 x 10⁻⁷

pH = -log[H⁺] = -log(4.75 x 10⁻⁷) = -(- 6.4 ) = 6.4

______________________

* The Concentration/Ka-value is the simplification test for quadratic equations used in Equilibrium studies. If the C/Ka > 100 then one can simplify the C(final) by dropping the 'x' if used in this type analysis. However, if the C/Ka value is < 100 then the x-value must be retained and the solution is determined using the quadratic equation formula.

for ax² + bx + c = 0

x = b² ± SqrRt(b² - 4ac) / 2a

Answer:

This is considered a hypothesis because it hasn't been confirmed. It is just a guess.

Explanation:

A hypothesis is a limited explanation of a phenomenon; a scientific theory is an in-depth explanation of the observed phenomenon. Law is a statement about an observed phenomenon or a unifying concept, according to Kennesaw State University. However, Newton's law doesn't explain what gravity is, or how it works.

Answer:

c

Explanation:

A. It is a statement of fact about how nature works instead of an explanation.

B. It provides an explanation for many observations and accepted hypotheses.

C. It describes how to test a possible explanation of one specific relationship.

D. It has not changed over time even though new technology has been developed.

Answer:

hydrogen is a non-metal and it has 1 valence electron

Explanation:

You can find the valence electrons on the bottom left of your periodic table, it is under the atomic number. Hydrogen is a non-metal because hydrogen conducts heat and electricity poorly.

Answer:

Glossopteris

Explanation:

Glossopteris is a fossil fern that helped support Wegener's hypothesis.

Hope this helps! Have a great day!

Answer:

291.7167

Explanation:

The molar mass of Fe₂(CO₃)₃ is 291.714 g/mol.

To calculate the molar mass of Fe₂(CO₃)₃, we need to consider the atomic masses of the individual elements present in the compound.

The molar mass of each element is as follows:

Fe (iron): 55.845 g/mol

C (carbon): 12.011 g/mol

O (oxygen): 15.999 g/mol

Now, let's calculate the molar mass of Fe₂(CO₃)₃:

Molar mass = (2 × atomic mass of Fe) + (3 × atomic mass of C) + (9 × atomic mass of O)

Molar mass = (2 × 55.845 g/mol) + (3 × 12.011 g/mol) + (9 × 15.999 g/mol)

Molar mass = 111.69 g/mol + 36.033 g/mol + 143.991 g/mol

Molar mass = 291.714 g/mol

Therefore, the molar mass of Fe₂(CO₃)₃ is approximately 291.714 g/mol.

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Answer: False

Explanation:

During Photosynethsis plants use sugar to make food.

Answer:

[tex]\boxed {\boxed {\sf B. \ -8.9 \ m/s^2}}[/tex]

Explanation:

Acceleration is found by dividing the change in velocity by the change in time.

[tex]a=\frac {v_f-v_i}{t}[/tex]

The parachute slows from 85 m/s to 45 m/s. Therefore, the final velocity is 45 meters per second and the initial velocity is 85 meters per second. The time is 4.5 seconds.

[tex]v_f= 45 \ m/s \\v_i= 85 \ m/s \\t= 4.5 \ s[/tex]

Substitute the values into the formula.

[tex]a= \frac {45 \ m/s- 85 \ m/s}{4.5 \ s}[/tex]

Solve the numerator and subtract.

[tex]a= \frac {-40 \ m/s}{4.5 \ s}[/tex]

Divide.

[tex]a=-8.888888889 \ m/s/s[/tex]

If we round this to the nearest tenth, the 8 in the hundredth place tells us to round the 8 up to a 9.

[tex]a \approx -8.9 \ m/s/s= -8.9 \ m/s^2[/tex]

The acceleration of the parachute is approximately -8.9 meters per square second. The value is negative because the parachute is slowing down.

Answer:

2.9x10⁻⁷L is the volume this amount of gas occupy

Explanation:

Assuming there are 7.8x10¹⁵ atoms

Based on the general gas law:

PV = nRT

Where P is pressure = 1atm

V is volume = Our incognite

n are moles of the gas:

7.8x10¹⁵ atoms * (1mol / 6.022x10²³ atoms) = 1.30x10⁻⁸ moles of gas

R is gas constant = 0.082atmL/molK

And T is absolute temperature = 273.15K at STP

Solving for Volume:

V = nRT/P

V = 1.30x10⁻⁸ moles*0.082atmL/molK*273.15K / 1atm

V = 2.9x10⁻⁷L is the volume this amount of gas occupy

Answer:

Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.

Answer:

The answer would be 15, letter D.

Explanation:

Since it has 5 electrons in its outermost shell, it will be located in group 15 in the periodic table.

The electron configuration of an atom of an element for the electrons in the s and p orbitals 15th group number of the element in the periodic table option D is correct.

Tha common electronic configuration of 15th group elements in ns2 np3, Group 15 elements in the modern periodic table are known as the pnictogens which means suffocation in Greek language.

This group consists of nitrogen (N), phosphorus (P), arsenic (As), antimony (Sb) and bismuth (Bi).

The group 15 elements consist of five valence electrons. Due to this the elements can either lose five electrons or gain three electrons in order to attain the stable configuration. The general electronic configuration of nitrogen family is ns 2 np 3.

therefore , because of ns2 np3 option D is correct.

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Answer:

i think the answer would be C

Explanation:

no matter what you do to the jar the mass will stay the same. unless you add more nails

Answer:

Neon

(if you want a thorough explanaion, just ask for one)

It is C! <3

The reason it's C because pt3 is Sugar science name get it?

Answer:

it can result in an increasing risk of the accumulation of decomposition products, self-heating (from the heat released by the slow decomposition reactions)

Magnesium can result in an increased risk of the accumulation of decomposition products, self-heating (from the heat released by the slow decomposition reactions)

Ammonium nitrate is used commonly in fertilizers; in pyrotechniques, herbicides, and insecticides; and in the manufacture of nitrous oxide.

When ammonium nitrate is heated, it decomposes exothermically into nitrous oxide and water.

Hence, Magnesium can result in an increased risk of the accumulation of decomposition products, self-heating (from the heat released by the slow decomposition reactions)

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Answer:

44.8 L

Explanation:

Ideal Gas Equation -

i.e.,

PV = nRT

where,

P = pressure

V = volume

n = moles

R = universal gas constant

T = temperature

Using the information given in the question, Volume of the gas can be calculated -

P = 101.3 kPa

V = ?

n = 2.00 moles

R = 8.31

T = 0 degree C = 273.15 K

Using the above data, and putting the data in the respective formula -

PV = nRT

101.3 kPa * V = 2.00 moles * 8.31 * 273.15 K

V = 44.8 L

Hence, the volume of the given gas = 44.8 L

Answer:

[tex]Fe_3PO_4+3Cs(CH_3COO)\rightarrow Cs_3PO_4+3Fr(CH_3COO)[/tex]

Explanation:

Hello there!

In this case, according to the given information, it is possible for us to illustrate the complete double displacement reaction between francium phosphate and cesium acetate as given on the question:

[tex]Fe_3PO_4+Cs(CH_3COO)\rightarrow Cs_3PO_4+Fr(CH_3COO)[/tex]

Which must the balanced due to the nonequal francium and cesium atoms:

[tex]Fe_3PO_4+3Cs(CH_3COO)\rightarrow Cs_3PO_4+3Fr(CH_3COO)[/tex]

Best regards!

Answer:

d. Mg²⁺

Explanation:

c. K⁺

d. Mg²⁺

Based on the Bohr's atomic model, the atom has electrons (Mass 0; Charge -1), protons (Mass 1; Charge +1) and neutrons (Mass 1; Charge 0).

The atomic number is equal to the number of protons. That means there are 10 protons. As the Neon is netural, the amount of electrons must be 10.

A neutral atom of Mg has 12 electrons, that means the Mg²⁺ has 10 electrons the same than Ne.

Right option is:

Answer:

option B,C and A are compound

Answer:

The ice cubes gain energy

Explanation:

The ice cubes are gaining energy from the water's carbon dioxide, or H2O. They then melt because they cannot hold that energy.

Answer:

option D

Explanation:

first quantum number of a 2s2

n = 2

second quantum number of a 2s2

l = 0 to n-1

l = 0, 1

For s orbital

l = 0

third quantum number of a 2s2

ml = - l to +l

ml = 0

fourth quantum number of a 2s2 electron be

?½ = spin down

½ = spin up

2s2 has 2 electrons 1 spin down and 1 spin up (starts with spin down)

ms = +1/2

Answer:

+1/2

Explanation:

Answer:

[tex]\color{Blue}\huge\boxed{Answer} [/tex]

The body regulates those levels in an example of homeostasis. When levels decrease, the parathyroid releases hormones. If calcium levels become too high, the thyroid helps out by fixing calcium in the bones and lowering blood calcium levels. The nervous system helps keep homeostasis in breathing patterns.

Answer:

scavenger or consumer

Explanation:

they collect and gather fruits, and different wild life

Answer:

359.3g of Na₂CO₃ are required

Explanation:

When sodium carbonate, Na₂CO₃ reacts with HCl, NaCl and H₂O are produced as follows:

Na₂CO₃ + 2HCl → 2NaCl + CO₂ + H₂O

Where 1 mole of sodium carbonate produce 2 moles of NaCl

To solve this question, we must find the moles of sodium carbonate required to produce the 6.78 moles of NaCl. With this mass and the molar mass we can find the mass of sodium carbonate as follows:

Moles Na₂CO₃:

6.78 moles NaCl * (1mol Na₂CO₃ / 2mol NaCl) = 3.39 moles Na₂CO₃

Mass Na₂CO₃ -Molar mass: 105.99g/mol:

3.39 moles Na₂CO₃ * (105.99g / mol) =

Answer:

V = 0.798 L

Explanation:

Hello there!

In this case, for this gas stoichiometry problem, we first need to compute the moles of carbon dioxide via stoichiometry and the molar mass of starting calcium carbonate:

[tex]3.56gCaCO_3*\frac{1molCaCO_3}{100gCaCO_3} *\frac{1molCO_2}{1molCaCO_3} =0.0356molCO_2[/tex]

Next, we use the ideal gas equation for computing the volume, by bearing to mind that the STP conditions stand for a pressure of 1 atm and a temperature of 273.15 K:

[tex]PV=nRT\\\\V=\frac{nRT}{P}\\\\V=\frac{0.0356mol*0.08206\frac{atm*L}{mol*K}*273.15K}{1atm} \\\\V=0.798L[/tex]

Best regards!

CaseAnswer:

-Mole of stearic acid used = 1.3*10^-3 mol

-Molecules of stearic acid there would be in 1 mole of stearic acid = 7.994*10^20 molecules

Explanation:

Know information from the problem are:

Mass concentration of C18H32O2 = 1.6x10^-4 g/ml, Molar mass of C18H32O2 = 284 g/mol.

Unit factor from drops to ml is 72 drops = 1ml. Therefore, for every drop, n, given, there would be n drops (1ml/ 72drops). The problem tells that stearic acid was added to hexane and that the addition process was done three-time with different amounts of drops. Think of this as releasing a substance from a burette during titration. If we convert the drops into millimeters, we would have 20 drops (1ml/72drops)= 0.28 ml, 21 drops (1ml/72drops)= 0.29 ml, and 16 drops (1ml/72drops)= 0.22 ml. [We need these volumes to determine the mass of stearic acid from mass concentration given.]

Unknown informations are:

V (volume in ml) =?

The mole of stearic acid used =?

Strategy

To calculate the mole of stearic acid used, we need the mass of stearic acid from the mass concentration. To get this we need a volume. Notice that those volumes (drops) are not the same ( it is safe to say that there is an error in the readings, as they were done independently). Therefore, we would find two or three values whose difference is smaller ( there is a little error). Subtract the smaller number from the larger number till you get a smaller difference ( do this for all three values).

The set of numbers with the smallest difference is 0.29 - 0.28=0.014, our concordant value.

Solutions

Now we us this set of numbers, 0.29-0.28, to determine an average volume :

V = (0.29-0.28)/2 (ml)

V= 0.285 ml

Now we can calculate the mass of stearic acid from the mass concentration:

m = C*V; m is the mass, C is the concentration in g/ ml, and V is the volume in ml.

m = (1.64*10^-4 g/ml)*(0.285 ml)

m = 4.674*10^-5 g

The mole of stearic acid used:

n = m/MM l; n is the mole of stearic acid, m is the mass of stearic acid, and MM is the molar mass of stearic acid.

n = 4.674*10^-5 g (284 g/mol)

n = 1.3274*10^-3

How many molecules of stearic acid would there be if it was 1 mol of stearic acid?

1 mol = 6.02214*10^23 molecule

Therefore, a conversion fraction would be:

6.02214*10^23 molecule/ 1 mol

Solution

Molecules of stearic acid in 1 mol =

1.3274*10^-3 mol (6.02214*10^23 molecule/ 1 mol)

= 7.994*10^20 molecules in 1 mol of C18H16O2

Answer:  16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.

The balanced chemical equation is:

[tex]3H_2+N_2\rightarrow 2NH_3[/tex]

According to stoichiometry :

[tex]3\times 22.4=67.2L[/tex] of [tex]H_2[/tex]  produce = [tex]2\times 22.4=44.8L[/tex] of [tex]NH_3[/tex] at STP

Thus 24.5 L of [tex]H_2[/tex]  will produce= [tex]\frac{44.8}{67.2}\times 24.5=16.3L[/tex] of [tex]NH_3[/tex] at STP

Thus 16.3 L of ammonia gas can be formed from 24.5 L of hydrogen gas at STP

Answer:

Caustic Base

Explanation:

"Barium hydroxide forms a strong caustic base in aqueous solution. It has many uses, e.g., as a test for sulphides; in pesticides; in the manufacture of alkali and glass. Use of barium hydroxide lime rather than soda lime, high sevoflurane concentration, high absorbent temperature, and fresh absorbent use."

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Hope I Helped, Feel free to ask any questions to clarify :)

Have a great day!

More Love, More Peace, Less Hate.

    -Aadi x

Answer:

what did you end up guessing

Explanation:

Answer:double displacement

Explanation:I just did it