difference between elimination and substitution​

Answer:

3.6 x 10²²molecules

Explanation:

Given parameters:

Mass of ethane gas  = 1.8g

Unknown:

number of molecules of ethane gas = ?

Solution:

To solve this problem, we first find the number of moles of ethane gas.

  Molar mass of ethane, C₂H₆  = 2(12) + 6(1) = 30g/mol

 Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

Insert the parameters and solve;

  Number of moles  = [tex]\frac{1.8}{30}[/tex]   = 0.06mole

 1 mole of a substance contains 6.02 x 10²³ molecules

 0.06mole of ethane will contain 0.06 x 6.02 x 10²³  = 3.6 x 10²²molecules

Answer:

it is a chemical change

Explanation:

Common physical changes include melting, change of size, volume, color, density, and crystal form. The classic baking soda and vinegar reaction provides evidence of a chemical change due to the formation of a gas and a temperature change.

Answer:

1.47 x 10⁻¹⁹J

Explanation:

Given parameters;

Frequency of wave  = 2.22 x 10¹⁴/s

Unknown:

Energy of the photon = ?

Solution:

The energy of a photon can be mathematically derived using the expression below;

        E = hf

  E is the energy

 h is the Planck's constant = 6.63 x 10⁻³⁴m²kg/s

 f is the frequency  

Insert the parameters and solve;

 E = 6.63 x 10⁻³⁴m²kg/s x  2.22 x 10¹⁴/s  

 E = 14.7 x 10⁻²⁰J or 1.47 x 10⁻¹⁹J

Given that :

Reaction equation ; [tex]HB_{r} + KOH ---> KBr + H_{2}O[/tex]

A) and B)  Determine the Initial pH before addition of titrant

First step : compute the value of pOH

pOH = - log ( [OH⁻])

        = -log ( 0.320 ) = 0.50

∴ Initial pH before the titrant is added = 14 - pOH

                                                               = 14 - 0.5 = 13.5

C ) Determine the pH of solution after 5 mL titrant is added

First step : determine the reacting moles of each substance

n kOH = 0.025 mL * 0.320 mol/L = 0.00800 mol

n HBr = 0.005 * 0.750 mol/L = 0.00375 mol

next step : compute the value of the concentration of OH⁻ in final solution

n kOH ( remaining ) = 0.00800 - 0.00375 = 0.00425 mol

final solution = 25.00 mL + 5.00 mL = 30.00 mL

∴ The value of the concentration of [ OH⁻] in 30.00 mL

  = [ OH⁻] = ( 0.0042 mol / 0.0300 mL )

                = 0.142 M

 hence pOH = - log (0.142) = 0.849

Final step; The pH of the solution after 5 mL of titrant is added

= 14 - pOH

= 14 - 0.849 = 13.15

Hence we can conclude that the initial pH before titrant was added is 13.50 and the pH after is as listed above.

Learn more : https://brainly.com/question/23313870

Answer:

The solubility of calcium phosphate is

2.21x10−4g/L.

Explanation:

Answer:

Volume of methanol present in solution = less than 3 ml

Explanation:

Given:

Volume of solution = 750 ml

Find:

Volume of methanol present in solution

Computation:

Volume of methanol present in solution = Volume of solution x 0.4%

Volume of methanol present in solution = 750 ml x 0.4%

Volume of methanol present in solution = 3 ml

Volume of methanol present in solution = less than 3 ml

The amount of methanol present in the 750 mL solution is 3 mL

From the question given above, the following data were obtained:

Percentage of methanol = 0.4%

Volume of solution = 750 mL

The volume of methanol present in the 750 mL of solution can be obtained as follow:

Volume = Percent × Volume of solution

Volume of methanol = 0.4% × 750

Volume of methanol = 0.004 × 750

Thus, the amount of methanol present in the 750 mL solution is 3 mL

Learn more: https://brainly.com/question/639233

Explanation:

The Brønsted–Lowry theory is an acid–base reaction theory which was proposed independently by Johannes Nicolaus Brønsted and Thomas Martin Lowry in 1923

Answer:

try a dude ummm yes ok yeah

Answer:

B, Gas B.

Explanation:

Answer:

pOH = 4

Explanation:

NaOH is a strong base which means that it dissociates completely in water. It will break apart into Na⁺ and OH⁻ ions.

NaOH ⇒ Na⁺ + OH⁻

Because NaOH dissociates completely into its respective ions in water, the moles of NaOH is equal to the moles of hydroxide ions. So, [OH⁻] = 0.0001 M.

Now to find the pOH, use the formula pOH = -log[OH⁻].

pOH = -log[OH⁻]

= -log(0.0001)

= 4

The pOH of the solution is 4.

Hope that helps.

Answer:

Elements

Explanation:

I did a quiz I'm 11 hope it helps\

Answer:

Explanation:

The new volume can be found by using the formula for Boyle's law which is

[tex]P_1V_1 = P_2V_2[/tex]

Since we are finding the new volume

[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]

From the question we have

[tex]V_2 = \frac{5 \times 633}{920} = \frac{3165}{920} \\ = 3.440217...[/tex]

We have the final answer as

Hope this helps you

Answer:

7.79 × 10³ L

Explanation:

Step 1: Calculate the total number of moles of carbon dioxide released

50 moles of carbon dioxide are released per hour. The moles released in a six-hour period is:

6 h × 50 mol/1 h = 300 mol

Step 2: Convert the temperature to the Kelvin scale

When working with gases, we need to consider the absolute temperature. We can convert from Celsius to Kelvin using the following expression.

K = °C + 273.15

K = 35 °C + 273.15 = 308 K

Step 3: Convert the pressure to atm

We will use the conversion factor 1 atm = 760 Torr.

740 Torr × 1 atm/760 Torr = 0.974 atm

Step 4: Calculate the volume of the gas

We will use the ideal gas equation.

P × V = n × R × T

V = n × R × T / P

V = 300 mol × (0.0821 atm.L/mol.K) × 308 K / 0.974 atm

V = 7.79 × 10³ L

The empirical formula for a compound : ZnO

The empirical formula is the smallest comparison of atoms of compound =mole ratio of the components

The principle of determining empirical formula

Determine the mass ratio of the constituent elements of the compound.  

Determine the mole ratio by by dividing the percentage by the atomic mass

Percentage Oxygen :

100\%-80.2%=19.8\%

mol ratio for Zn : O =

[tex]\tt \dfrac{80.2}{65.38}\div \dfrac{19.8}{16}\\\\1.227\div 1.238\rightarrow divide~by~smallest(1.227)\\\\1\div 1[/tex]

Explanation:

that u know right .........................

Answer:

all for it 8) !! i have several friends that are trans in fact.

Explanation:

ppl that don't support trans peeps are going to get punted into the sun with no mercy

im nonbinary, but also identify as trans too (the white stripe on the transgender flag is actually "for those who are transitioning or consider themselves having a neutral or undefined gender," according to Monica Helms, who made the most commonly seen trans flag. :]  they don't all identify as trans but can if they want to.

also, a common misconception is that all nonbinary people have to/use they/them pronouns, which is not true. they can use whatever they want because pronouns do not equal gender in most cases. also because they don't have to be put into a strict box of what you can and can't use.

Answer:

inertia

Explanation:

Answer: 90

Explanation: Sugar dissolves faster in hot water than it does in cold water because hot water has more energy than cold water. When water is heated, the molecules gain energy and, thus, move faster. As they move faster, they come into contact with the sugar more often, causing it to dissolve faster.

Answer:

90 c

Explanation:

The sugar dissolve in the hottest bc of the heat it will melt in with the water i an pretty sure

Answer:

* [tex]HI (aq) +NaOH (aq) \rightarrow NaI(aq)+H_2O(l)[/tex]

* [tex]H_2CO_3 (aq) + Sr(OH)_2\rightarrow SrCO_3(s)+2H_2O(l)[/tex]

* [tex]Ca(OH)_2 (s) +H_2SO_4 (aq)\rightarrow CaSO_4(aq)+2H_2O(l)[/tex]

Explanation:

Hello!

In this case, since neutralization chemical reactions are carried out when an acid and a base react to produce a salt and water, for the first reaction, HI (aq) and NaOH (aq), we can write:

[tex]HI (aq) +NaOH (aq) \rightarrow NaI(aq)+H_2O(l)[/tex]

Whereas the salt, sodium iodide remains aqueous and water liquid. Next, when carbonic acid and strontium hydroxide react, strontium carbonate as the salt precipitates out and water is also produced:

[tex]H_2CO_3 (aq) + Sr(OH)_2\rightarrow SrCO_3(s)+2H_2O(l)[/tex]

Finally, when calcium hydroxide and sulfuric acid react, the compound calcium sulfate as the salt and water are produced as shown below:

[tex]Ca(OH)_2 (s) +H_2SO_4 (aq)\rightarrow CaSO_4(aq)+2H_2O(l)[/tex]

Best regards!

Answer:

Explanation:

2N₂O(g) → 2N₂(g) + O₂(g)

molecular weight of N₂O = 44

∆Hº = –166.7 kJ/mol

44 g of N₂O decomposes to give 166.7 kJ of heat

2.25 g of N₂O decomposes to give 166.7 x 2.25 / 44 kJ of heat

= 8.51 kJ of heat .

Answer:

The uncertainty of inventiveness and futuristic ideas usually deal with science and technology. ... This is usually linked to futuristic ideas, which may not fit in today's society, but which impose improvements, or not, for societies in the future.

Answer:

24.5g

Explanation:

Given parameters:

Mass of oxygen gas = 21.8g

Unknown:

Mass of water  = ?

Solution:

This problem deals with the decomposition of water;

    Reaction equation;

                  2H₂O →  2H₂  +  O₂

2 mole of water will produce 1 mole of oxygen gas

First find the number of mole of the oxygen gas given;

          Number of moles  = [tex]\frac{mass}{molar mass}[/tex]

    molar mass of O₂   = 2(16) = 32g/mol

  Number of moles of O₂  = [tex]\frac{21.8}{32}[/tex]   = 0.68moles

    1 mole of oxygen gas will be produced from 2 mole of water

     0.68moles of oxygen gas will be produce from  0.68 x 2 moles of water;   = 1.36moles of water

Mass of water = number of moles x molar mass

  Molar mass of water = 2(1) + 16  = 18g/mol

Mass of water  = 1.36 x 18  = 24.5g

Given :

The pressure of 50.0 mL of oxygen gas at 100 ºC increases from 735 mm Hg to 925 mm Hg.

Temperature remains constant.

To Find :

The final volume.

Solution :

735 mm Hg = 0.967 atm

935 mm Hg = 1.230 atm

We know, at constant temperature :

[tex]P_iV_i=P_fV_f\\\\V_f=\dfrac{P_iV_i}{P_f}\\\\V_f=\dfrac{0.967\times 50}{1.230}\\\\V_f=39.31 \ mL[/tex]

Therefore, final volume is 39.31 ml.

Hence, this is the required solution.

Answer:

C. Speed

Explanation:

Density differences in different materials are able to change the speed of a wave.

Answer:

Speed

Explanation:

The speed or mass of something can totally change the direction of the wave

protons

there aint rlly an explanation tbh

Answer:

Nucleons

The mass number of a nucleus is the number of protons and neutrons called the nucleons! Nucleons are the sum of protons and neutrons present in the nucleus of an atom.

Answer:

a. K = [H+][NO2-]/[HNO2]

Explanation:

The computation of the expression of the equilibrium constant is shown below:

Given that the weak acid is HNO_2 that exist in the solution that aqueous

The dissociation equation of [tex]HNO_2[/tex]

[tex]HNO_2(aq) \rightarrow NO_{2}^{-} (aq) + H^{+}(aq)[/tex]

Now

Acidionization constant i.e.

[tex]k_a = \frac{[NO_{2}^{-}][H^{+}]}{HNO_{2}}[/tex]

Therefore the correct option is a.

Hence, the same is to be considered

Answer:

A) species

Explanation:

Of the Linnaeus's groupings, organisms at the species level are the most closely related to one another.

The species level is the lowest level of classification in the Linnaean system of classification.

Answer:

Ammonia is a weak electrolyte, weak base.

Option e.

Explanation:

Ammonia can take a proton from water to make ammonium.

It is a base, because it takes proton.

When a compound can take protons, we know that is base, according to Bronsted Lowry theory.

We can't describe ammonia as a base, according to Arrhenius, but we know it is base according to Lewis, because the N from the ammonia can be a donor of its electron pair.

It is weak because an small amount of ammonia, can react to produce ammonium, between the protons of water. This is the equilibrium, where the ammonia is considered as the conjugate strong acid of ammonia.

NH₃ +  H₂O  ⇄  NH₄⁺  +  OH⁻     Kb

All the amines are considered as weak bases, because they look like ammonia, where the H of NH₃ are replaced by others chains.

------NH₂

-----NH-----

The element you are looking for is Scandium, the 4th element in the third group.

Answer:

2.938 mol Pb(NO₃)₄

Explanation:

Step 1: Given data

Step 2: Write the balanced equation

4 (NH₄)₃PO₄ + 3 Pb(NO₃)₄ = Pb₃(PO₄)₄ + 12 NH₄NO₃

Step 3: Calculate the number of moles of Pb(NO₃)₄required to produce 11.75 moles of NH₄NO₃

The molar ratio of Pb(NO₃)₄ to NH₄NO₃ is 3:12.

11.75 mol NH₄NO₃ × (3 mol Pb(NO₃)₄/12 mol NH₄NO₃) = 2.938 mol Pb(NO₃)₄