Am nevoie rapid de aceste exercitii

Am Nevoie Rapid De Aceste Exercitii

Answers

Answer 1

Answer:

I will find the answer for you

Explanation:

Just a minute


Related Questions

1. Can you please put the following chromatography solvents in order of polarity as a chromatography solvent: acetone, n-propanol,
water, hexane, diethyl ether, methanol and explain
2. chromatography with a mixture of n-propanol and water. Would it make sense to add hexane to this mixture to try and make it work better? why?
3. The basic food colors you can buy are red, blue, green, and yellow. Think about what you know about colors
and predict which of these might be a single colored compound and which ones might contain more than one.
Write down your prediction. If you have the colors listed and want a purple color, what would you do?

Answers

The order of increasing polarity of the solvents is; hexane< diethyl ether < acetone < n-propanol < methanol  < water

What is chromatography?

Chromatography literarily means "color writing". It provides a means of separating the components of a mixture based on its components.

The solvent in chromatography is the mobile phase while the adsorbent is the stationary phase. The order of increasing polarity of the solvents is; hexane< diethyl ether < acetone < n-propanol < methanol  < water

If we have a mixture of n-propanol and water, it would be good to add hexane to the mixture for the sake of the elution of non-polar solutes.

The secondary color green may be composed of more than one color while red, blue and yellow are single colors.

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Procedure for Lab: Enthalpy ?

I have a lab on Edge that's about Enthalpy. The assignment is called " Lab: Enthalpy". If someone could help me with the procedure of the lab, that would be nice. (I don't need the data table, just the procedure.)

Answers

The enthalpy refers to the thermodynamic characteristics that have chemical systems associated with their internal energy.

What is enthalpy?

The enthalpy refers to the thermodynamic features of the chemical systems associated with the energy of such systems.

Enthalpy is used to estimate the ability of the system to perform work and release energy in the form of heat.

It is well known that different types of chemical reactions may exhibit different enthalpies, which can be estimated by the internal energy, pressure of the system and volume.

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Answer:

Here you are <3

Explanation:

I attached the one I just submitted

Amphetamine (C9H13N) is a weak base with a pKb of 4.2.

Calculate the pH of a solution containing an amphetamine concentration of 215 mg/L .
Express your answer to two decimal places.

Answers

Weak base: [OH⁻] = √Kb.C

pKb = 4.2

[tex]\tt Kb=10^{-4.2}[/tex]

c = concentration

MM Amphetamine (C9H13N) = 135.21 g/mol

c = 215 mg/L = (0.215 g : 135,21 g/mol) / L = 0.00159 mol/L = 1.59  x 10⁻³ mol/L

[tex]\tt [OH^-]=\sqrt{10^{-4.2}\times 1.59\times 10^{-3}}=3.17\times 10^{-4}[/tex]

pOH = 4 - log 3.17

pH = 14 - (4 - log 3.17)

pH = 10 + log 3.17 = 10.50

At 4.5 atm of pressure, the solubility of a gas is 9.5 g/L.
How much gas, in grams, will dissolve in 1 L if the pres.
sure is reduced by 3.5 atm?

Answers

For a gas at 4.5 atm of pressure, the solubility of a gas is 9.5 g/L.

How much gas, in grams, is mathematically given as

s2=8.3782grams

What is the amount of gas in grams?

Generally, the equation for the   is mathematically given as

Si /S2 √P1/√P2

Therefore

[tex]s2=9.5*\sqrt{3.5}/\sqrt{4.5}[/tex]

s2=8.3782g

In conclusion. The solubility is

s2=8.3782g

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What temperature creates hail

Answers

Answer:

32 °F

Formation. Hail forms in strong thunderstorm clouds, particularly those with intense updrafts, high liquid water content, great vertical extent, large water droplets, and where a good portion of the cloud layer is below freezing 0 °C (32 °F).

Explanation:

brainlist me and that's all I know and we have the same module I guess

23.4 grams of Al2(SO3)3 is yielded through a chemical reaction. How many moles is this?

Answers

Answer:

.0796  mole

Explanation:

Al2 (SO3)3      add the molecular weights

2 * Al = 2 * 26.982  +  

 3 * S  = 3 * 32.06   +

   9 * O  = 6 * 15.999      = 294.135  gm   per mole

Now... you have   23.4 grams of this substance

  23.4/294.135 = .0796 mole

EDITED !

Determine the difference between archaea and bacteria. (1 point)

All bacteria are unicellular organisms, while some archaea are multicellular.


Archaea live in extreme environments, while bacteria can be found in most places on Earth.

Bacteria and archaea have different shapes.


Archaea is the domain of life that includes the plant and animal kingdoms, while the bacteria domain includes fungi and protists.

Answers

Answer:

I have this work and I'm in 5th grade

Explanation:

Answer:

Archaea live in extreme environments, while bacteria can be found in most places on Earth.

Explanation:

Doing a the test now and this is the answer.

1) Identify two different mineral nutrients present in the fertilizer
that helped the plant recover. Then, describe how each nutrient
benefits the plant.

Answers

The two different mineral elements that a fertilizer can contain are:

Phosphorus - build up of nucleic acid and ATPNitrogen- synthesis of proteins

What are fertilizers?

Fertilizers are chemical substances added to the soil in order to improve crop growth and development.

Fertilizers are artificially made to contain mineral elements that are needed by the plants. Some of the mineral elements are as follows:

PhosphorusNitrogenPottasium

Phosphorus helps in the build up of nucleic acids and ATP for energy. Nitrogen is useful in the synthesis of proteins.

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Answer:

is the answer above right? im literally struggling rn

Explanation:

1) A solution is prepared with 0.55 M HNO2 and 0.75 M KNO2. Fill in the ICE Table with the appropriate values

2) The Ka for this solution of HNO2 is 6.8x10^-4. Based on the ICE table, set up the expression for Ka.

3) Based on your ICE table, determine the pH of the buffer solution

Answers

Based on the calculations through the ICE table, the pH of the buffer solution is equal to 3.30.

Given the following data:

Concentration of [tex]HNO_2[/tex] = 0.55 M.Concentration of [tex]KNO_2[/tex] = 0.75 M.Rate constant = [tex]6.8 \times 10^{-4}[/tex]

How to determine the pH of the buffer solution.

First of all, we would write the properly balanced chemical equation for this chemical reaction:

                                     [tex]HNO_2(aq)\rightleftharpoons H^{2+} (aq)+ KNO_2^{-}(aq)[/tex]

Initial cond.                       0.55M              0          0.75M

    [tex]\Delta C[/tex]                                   -x                   x               x

At equib.                           0.55M - x         0 + x      0.75M + x

From the ICE table, the Ka for this chemical reaction is given by:

[tex]K_{a}=\frac{[H^+][NO_2^+]}{HNO_2} \\\\H^+ = K_{a}\frac{[HNO_2]}{[NO_2^+]} \\\\H^+ = 6.8 \times 10^{-4} \times \frac{0.55}{0.75} \\\\H^+ = 6.8 \times 10^{-4} \times 0.733\\\\H^+ = 4.98 \times 10^{-4} \;M[/tex]

Now, we can calculate the pH of the buffer solution:

[tex]pH=-log[H^+]\\\\pH=-log[4.98 \times 10^{-4}]\\\\pH=-(-3.30)[/tex]

pH = 3.30.

Alternatively, you can calculate the pH of this buffer solution by applying Henderson-Hasselbalch equation:

[tex]pH =pka+ log_{10} \frac{A^-}{HA}[/tex]

Where:

HA is acetic acid.[tex]A^-[/tex]  is acetate ion.

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What type of molecule is cis-2-pentene?
O A. Alkane
B. Alkyne
C. Branched alkane
D. Alkene

Answers

The given molecule, cis-2-pentene, is an Alkene. The correct option is D. Alkene

Saturated & Unsaturated Hydrocarbons

Alkanes, Alkenes, and Alkynes are examples of simple hydrocarbons.

Alkanes are the simplest organic compounds. They have only single bonds between carbon atoms and are called saturated hydrocarbons. Their nomenclature usually ends in -ane.

Alkenes on the other hand have at least one carbon-carbon double bond. Their nomenclature usually ends in -ene.

Alkynes have one or more carbon-carbon triple bonds.Their nomenclature usually ends in -yne. Alkenes and alkynes are called as unsaturated hydrocarbons.

The given molecule is cis-2-pentene

Since the name of the molecule ends in "ene", the molecule is an Alkene.

Hence, the given molecule, cis-2-pentene, is an Alkene. The correct option is D. Alkene

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Answer: Alkene

Explanation: just took tha test

the pH of an acidic solution is 2.47. what is the [H+]

Answers

[tex]pH=-\log[H^{+}]\\\\\implies [H^{+}] =10^{-pH}=10^{-2.47}=0.0034~M[/tex]


Calculate the % by mass concentration for each of the following solutions. Match the answers.
1.25g NaCl in 100.0g of solution = [a]%
ce
2.50g K2Cr2O7 in 96.0g of solution = [b]%
nts
10.0g CaCl2 in 250.0g of solution = [c]%
ns
20.0g Kl in 100.Ogof solution = [d]%


Answers

The percentage by mass of each of the compounds would be 40%, 2.6%, 4%, and 20% respectively

Percentage by mass

The percentage by mass of a substance is given by:

Percent by mass = mass of substance/mass of solution x 100%.

For NaCl: Percent by mass = 25/100 = 40%For K2Cr2O7: Percent by mass = 2.50/96 = 2.6%For CaCl2: Percentage by mass = 10/250 = 4%For KI: Percent by mass = 20/100 = 20%

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Oxidation Number of Carbon in C6H12O6​

Answers

Correct option is C)

C

6

H

12

O

6

6x+12−12=0

C has oxidation number = 0

Sorry if my answers wrong.

Determine whether aqueous solutions of the following salts are acidic, basic, or neutral: (a) Al(NO3)3 (b) RbI (c) KHCO2 (d) CH3NH3Br

Answers

The aqueous solution and their respective properties include the following:

Al(NO3)3 - acidicRbI - neutralKHCO2 - basic CH3NH3Br - acidic

What is pH?

This is defined as the degree of acidity or alkalinity of a substance and pH from 1.0 - 6.9 is acidic, 7 is neutral while 7.1 - 14.0 is basic.

The aqueous solutions and their appropriate pH can be seen above which is the right choice.

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According to the given equation, how many moles of O, are required to react with 4.71 moles of C4H10?
2C4H10 + 1302 —8CO2 + 10 H

Answers

According to the given equation, 2C4H10 + 1302 — 8CO2 + 10H, 2 moles of O are required to react with 4.71 moles of C4H10.

How to calculate number of moles?

The number of moles of a compound can be calculated stoichiometrically as follows:

The balanced chemical equation is given as follows:

2C4H10 + 1302 — 8CO2 + 10H

Based on the above equation, 2 moles of C4H10 reacts with 13 moles of O

Therefore; 4.71 moles of C4H10 will react with 4.71 × 6.5 = 30.62 moles of O

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Answer: 30.6

Explanation:

What is The fmu (grams/mole) for disulfur hexachloride *the formula for it is S2Cl6*

Answers

Hexasulfur Dichloride

Name: Hexasulfur Dichloride

Formula: S2Cl6

Molar Mass:276.848

Example Reactions:

• S2Cl6 + 4H2O = 2SO2 + 6HCl + H2

As a chemical energy is converted into heat energy during a reaction the total energy of the system

Answers

When a chemical energy is converted to hear during a chemical reaction, the total energy of the system remain constant.

Law of conservation of Energy?

Law of conservation of energy state that the today energy interacting with bodies in a isolated system remain constant

the Law of Conservation state that the total energy in a system remain unchanged, and that oftentimes a chemical reaction will absorb or release energy in the form of heat, light, or both.

Therefore, The total energy of the system remain constant.

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How many kJ of heat do you need to raise the temperature of 200 g of Aluminum from 80 °C to 100 °C?

Remember to convert your answer to kJ. Round your answer to two decimal places.

Answers

Answer:

0.01

Explanation:

100 -80=20

200/20=10/1000=0.01kj

what is the volume of
NH4 NO3(s) — N2O(g) + 2H2O(g)

Answers

Answer:

Explanation:

NH4NO3(s) N2O(g) + 2H2O(g) What is the total volume of gases produced at 546 K and 1.00 atm pressure when 240 g of ammonium nitrate undergoes the above decomposition reaction? A) 9 × 22.4 L B) 3 × 22.4 L C) 12 × 22.4 L D) 18 × 22.4 L E) 6 × 22.4 L

Between a water molecule and an anion, like Cl-, a _____A_____ occurs between a _____B_____ of the water molecule and the anion.

Answers

Between a water molecule and an anion, like Cl-, a hydrogen bon occurs between hydrogen atom of the water molecule and the anion.

What is hydrogen bond?

Hydrogen bond is a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other. Hydrogen atom in water molecule attract anion due to presence of hydrogen bond.

So we can conclude that hydrogen bond occurs between hydrogen atom of the water molecule and the anion.

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Answer:

Explanation:88766

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How many moles of HCl are in 57 mL of 0.17 M HCl ?

Answers

[tex]\text{Given that,}\\ \\\text{Volume,}~V= 57 mL = 0.057 L\\\\\text{Molar concentration,}~ S = 0.17 ~mol/L\\\\\text{Number of moles,} ~ n=?\\\\S = \dfrac{n}{V} \\\\\implies n = SV = 0.17\times 0.057 =0.00969 ~mol ~ HCl[/tex]

How many moles of carbon are present in 1.50mole of aspirin , C_{9}*H_{8} * O_{4}

Answers

Given the molecular formula of aspirin, C₉H₈O₄, in 1.50 moles of aspirin there are 13.5 moles of carbon.

What is a mole?

The mole is the SI base unit for the amount of matter. 1 mole of particles contains a number of Avogadro's particles.

We have 1.50 moles of aspirin, C₉H₈O₄. According to the molecular formula, the molar ratio of C₉H₈O₄ to C is 1:9.

1.50 mol C₉H₈O₄ × (9 mol C/1 mol C₉H₈O₄) = 13.5 mol C

Given the molecular formula of aspirin, C₉H₈O₄, in 1.50 moles of aspirin there are 13.5 moles of carbon.

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Find the acceleration of the 2 kg block in the following diagram. ( Hint find the net force!)​

Answers

Answer:
2m/s^2
Explanation:
Fnet = F2-F1
ma = 8-4
2a = 4
Dividing both sides by 2
a = 2
Therefore (a) thus acceleration is 2m/s^2

The acceleration of the block will be -2 m/s² in the backward direction.

What is force?

Force is defined as the product of mass of the body and the acceleration with which it is moving. Mathematically -

F = ma

It is a vector quantity. In the three dimensional coordinate system, the force vector can be resolved as -

[F] = F[x] a[x] + F[y] a[y] + F[z] a[z]

Given is a diagram in which two forces are acting on a block.

We can write -

Force 1 on block [F1] = 4 a[x]

Force 2 on block [F2] = 8 (- a[x]) = - 8 a[x]

Resultant of forces [F] = [F1] + [F2] = 4 a[x] + ( - 8 a[x]) = - 4 a[x]

Now, we know that -

F = MA

A = F/M

In vector form, acceleration will be -

[A] = - 1/m × (4 a[x])

[A] = -1/2 × (4 a[x])

[A] = - 2 a[x]

Therefore, the acceleration of the block will be -2 m/s² in the backward direction.

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b. How many grams of H20 is needed to react with 20.0 grams of P4010
P4010 + 6H20 -----> 4H3PO4

Answers

20

12 3.2

12bw

7. A certain music box ha the shape of a cube. Ea

cm long. What is the surface area of the box?

8. Find the amount of tin needed to make a milk to

cm and a height of 5cm.

9. Angelo is wrapping a present. The box he is using is

of 10 cm, a width of 7 cm and a height of 5 cm. Find

gift wrapper he needs to wrap the entire box?

10.

The side of the a cube measures 12 cm. Sc

a

help me this is due soon

Answers

Answer:

Hot magma change climate continents drift block sunlight folded mountains form rock deposits

Explanation:

brainliest now

What is the difference between metallic and non metallic oxides?​

Answers

Answer:

Metal oxides are compounds composed of metal ions and oxide ions. Nonmetal oxides are compounds composed of nonmetal atoms and oxygen atoms. The main difference between metal oxides and non metal oxides is that metal oxides are basic compounds whereas nonmetal oxides are acidic compounds.

Explanation:

have a great day ahead

tC

Answer:

Metals react with oxygen to form metallic oxide while Nonmetals react with oxygen to form non-metallic oxide. metallic oxides are basic in nature while Nonmetallic oxides are acidic in nature.


Metal oxides are compounds composed of metal ions and oxide ions. Nonmetal oxides are compounds composed of nonmetal atoms and oxygen atoms. The main difference between metal oxides and non-metal oxides is that metal oxides are basic compounds whereas nonmetal oxides are acidic compounds.



METALS:

Metals usually do not combine with hydrogen. Only a few reactive metals combine with hydrogen to form ionic metal hydrides.

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

NON-METALS:
Non-metals react with hydrogen to form stable, covalent hydrides.







Explanation:

Have a great rest of your day
#TheWizzer

why is it necessary to standardize a secondary standard before use?

Answers

Answer:

As the name implies, a secondary standard is used by standard laboratories, which include companies involved in the preparation of reagents and kits, as well as laboratories responsible to produce quality control material for use by other laboratories. They use the primary standard as the primary calibrator or primary reference material, and they calibrate their instruments against it. Smaller labs use secondary standards to calibrate control material for analysis of unknown concentrations. For smaller labs, secondary standard serves as an external quality control. As a result, it is essential that the secondary standard be standardized against the primary standard before it can be applied.

I hope this helps you

:)

In cells, __________ are proteins that are needed to lower the amount of energy required to start chemical reactions

Answers

Answer: I think it’s enzymes

Explanation:

What are valence electrons?

A electrons in the outermost level of each atom
B electrons found in the s or p orbitals of atoms
C electrons in the innermost level of each atom
D electrons produced by the radioactive decay of the nucleus of an atom

Answers

A electrons in the outermost level of each atom

Which of the following represents the velocity of a moving object?
Select one:

40 m north.

40.

40 m/s north.

40 m/s.

Answers

Answer:

The correct answer would be 40 m/s

Explanation:

The reason 40 m/s is the correct answer is because m/s stands for meters per second.

Hope this helps you with what you're working on! :D

Answer:

40 m/s north

Explanation:

Velocity is a vector quantity, so it have both direction and magnitude.

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