Can anyone just give me the answers?

Answer:

0.29 J/g.°C

Explanation:

Step 1: Given data

Step 2: Calculate the temperature change (ΔT)

ΔT = 99.4 °C - 92.6 °C = 6.8 °C

Step 3: Calculate the specific heat of the substance (c)

We will use the following expression.

Q = c × m × ΔT

c = Q / m × ΔT

c = 49 J / 25.0 g × 6.8 °C = 0.29 J/g.°C

Answer:

The answer is "2%"

Explanation:

Equation:

[tex]HNO_2\ (aq) \leftrightharpoons H^{+} \ (aq) + NO_2^{-}\ (aq) \\\\\ K_a = 4.0\times \ 10^{-4}[/tex]

[tex]H^{+}=?[/tex]

Formula:

[tex]Ka = \frac{[H^{+}][NO_2^{-}]}{[HNO_2]}[/tex]

Let

[tex][H^{+}] = [NO_2^{-}] = x[/tex] at equilibrium

[tex]x^2 = (4.0\times 10^{-4})\times 1.0\\\\x = ((4.0\times 10^{-4})\times 1.0)^{0.5} = 2.0 \times 10^{-2} \ M\\\\[/tex]

therefore,

[tex][H^{+}] = 2.0\times 10^{-2} \ M = 0.02 \ M[/tex]

Calculating the % ionization:

[tex]= \frac{([H^{+}]}{[HNO_2])} \times 100 \\\\= \frac{0.02}{1}\times 100 \\\\= 2\%\\\\[/tex]

The approximate percent ionization of HNO₂ in a 1.0 M HNO₂ (aq) solution is 2%.

% ionization of any compound will be calculated as follow:

% ionization = ([ion]/[acid or base]) ₓ 100

Given chemical reaction with ICE table will be represented as:

                           HNO₂(aq) → H⁺(aq) + NO₂⁻(aq)

initial                          1                0             0

change                      -x               +x           +x

equilibrium              1-x                x             x

Equilibrium constant will be represented as:
Ka = [H⁺][NO₂⁻] / [HNO₂]

Acid dissociation constant for HNO₂ = 4×10⁻⁴

Putting all values in the above equation, we get

4×10⁻⁴ = x² / 1-x

Value of changeable quantity is very less, so we neglect from the concentration of HNO₂.

4×10⁻⁴ = x²

x = 2 × 10⁻²

So, the concentration of H⁺ ion = 2 × 10⁻²M

Now we put all these values in the % ionization equation, we get

% ionization = (0.02/1) × 100 = 2%

Hence , % ionization is 2%.

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Answer:

A

Explanation:

Answer:

C

Explanation:

Pretty sure!

Answer:

QED,  EDQ,  DQE,  EQD,  DEQ,  QDE

Explanation:

The structure of all possible peptides that contain the given amino acids are :

QED,  EDQ,  DQE,  EQD,  DEQ,  QDE

where : Asp is represented by the letter code D

             Glu is represented by the letter code E

             Gln is represented by the letter code Q

Note : when three amino acids combine they form what is known as tripeptide ( i.e. contains two peptide linkages ) while a peptide linkage is been formed by the combination of a carboxyl group of an amino acid and the amino group of different amino acid

Answer:

82.0 mL

Explanation:

Step 1: Given data

Step 2: Calculate the required volume of the concentrated acid

We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the concentrated acid using the dilution rule.

C₁ × V₁ = C₂ × V₂

V₁ = C₂ × V₂ / C₁

V₁ = 1.00 M × 1.00 L / 12.2 M = 0.0820 L = 82.0 mL

Answer:

1. CH₂Br > CH₂OH > CH₂NH₂ > CH₃

2. -F > -CHO > - CH₂OH > CH₃

Explanation:

The arrangement of the above atom is due to their atomicity and electronegativity of the given compounds.

From (1) we will realize that Bromine (Br) possesses the greatest priority because its atomic number is the highest. This is followed by oxygen (O) in CH₂OH since atomic no 8 is higher than that of Nitrogen N(7). Lastly, CH₃ has the only hydrogen attached to it with the atomic no of (1)

In the second part of the question>

The electronegativity of an element increases across the period and down the group. Fluorine is highly electronegative and contains the highest atomic number of oxygen in -CHO. The oxygen (O) in -CHO has a double bond which gives an edge over the (O) in CH₂OH. Lastly, CH₃ contains a substituted hydrogen atom

Answer:

78.07

Explanation:

them seperatly is

Calcium Ca 51.333%

Fluorine F 48.667%

Answer:

The kinetic molecular theory of matter states that: Matter is made up of particles that are constantly moving. All particles have energy, but the energy varies depending on the temperature the sample of matter is in. This in turn determines whether the substance exists in the solid, liquid, or gaseous state.

Explanation:

Kinetic molecular theory explains the properties of solids, liquids and gases. As per this theory, matter is made of particles.

What is kinetic theory?

Kinetic molecular theory explains the properties of different states of matter. According to this theory matter is made up of particles. But the theory is mostly applies for gases.

According to kinetic theory  of gases, gaseous substances consists of tiny spherical particles which are located apart from each other and hence no intermolecular force acts between them. They are in random motion and gains kinetic energy.

The kinetic energy of particles are temperature dependant and it increase as temperature rises. The collision between the particles and the particle and wall of the container in which they are will be elastic collision.

These concepts are  applicable only for ideal gases. An less applicable for other states of matter.

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Answer:

Explanation:

10 moles of oxygen atoms.\ \textbf{b)} 91.8 moles of oxygen at

[tex]pH = - log({H}^{ + } ) \\ pH = - log(1.0 \times {10}^{ - 8} ) \\ pH = 8[/tex]

pH is the measure of acidity and alkalinity of a solution. A pH value less than 7 means the solution is acidic. A pH value greater than 7 means the solution is basic. A pH value of 7 means the solutions is neutral.

Answer:

9 moles of NaNO3 is obtained

Explanation:

The balanced chemical reaction equation for the reaction is;

Al(NO3)3 + 3NaCl-------> 3NaNO3 + AlCl3

Now, we have to determine the limiting reactant. The limiting reactant yields the least amount of NaNO3.

1 mole of Al(NO3)3 yields 3 moles of NaNO3

4 moles of Al(NO3)3 yields 4 * 3/1 = 12 moles of NaNO3

Also,

3 moles of NaCl yields 3 moles of NaNO3

9 moles of NaCl yields 9 * 3/3 = 9 moles of NaNO3

Hence, NaCl  is the limiting reactant and 9 moles of NaNO3 is obtained.

9 moles of NaNO₃ is obtained.

[tex]Al(NO_3)_3 + 3NaCl-----> 3NaNO_3 + AlCl_3[/tex]

From the reaction, it is seen that the limiting reactant yields the least amount of NaNO₃.

1 mole of Al(NO₃)₃ yields 3 moles of NaNO₃

4 moles of Al(NO₃)₃ yields 4 * 3/1 = 12 moles of NaNO₃

Also,

3 moles of NaCl yields 3 moles of NaNO₃

9 moles of NaCl yields 9 * 3/3 = 9 moles of NaNO₃

Hence, NaCl  is the limiting reactant and 9 moles of NaNO₃ is obtained.

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Answer:

[tex]\frac{P_{solution}}{P_{solvent}^{vap}} =0.75[/tex]

Explanation:

Hello there!

In this case, since the solvation of a nonvolatile-nondissociating solute in a volatile solvent is modelled via the Raoult's law:

[tex]P_{solution}=x_{solvent}P_{solvent}^{vap}[/tex]

Thus, we can calculate the ratio of the vapor pressure of the solution to that of the pure solvent, mole fraction, as shown below:

[tex]x_{solvent}=\frac{P_{solution}}{P_{solvent}^{vap}} =\frac{n_{solvent}}{n_{solute}+n_{solvent}}[/tex]

Thus, we plug in the moles of solvent and solute to obtain:

[tex]\frac{P_{solution}}{P_{solvent}^{vap}} =\frac{3}{3+1}\\\\ \frac{P_{solution}}{P_{solvent}^{vap}} =0.75[/tex]

Regards!

Answer:

0.147

Explanation

PV/RT

Answer:

Option a. Benzenecarbonitrile

Explanation:

You are not providing the picture of the compound. However, I manage to find the picture of it, so I'm gonna answer this with the picture. Its attached here at the end.

As for the IUPAC name of this compound, it would be Benzenecarbonitrile, or simply, benzonitrile.

This compound has the molecular formula C₆H₅CN. It receives this name over the other ones, because this is a aromatic cyanide, and aromatic cyanide has nitriles behavior, (Strength of the nitrogen over the carbon), therefore, this group has priority over the whole molecule. As the principal chain is the benzene, the carbonitrile is the radical of the group, and when cyano groups are as radical and not as principal chains, it has a behavior of nitrile, and it's named as nitrile. therefore, option b, cannot be the name.

phenylcyanide is naming the phenyl as radical, but the benzene is the principal group in this compound, and the cyanide is the radical. It happens the same thing with cyanophenyl.

Hope this helps

Answer:

m = 7.29 grams

Explanation:

Given that,

Initial temperature, T₁ = 25ºC

Final temperature, T₂ = 31.5ºC

The specific heat of the metal is 0.89 J/gºC.

We know that the heat released due to the change in temperature is given by :

[tex]Q=mc\Delta T\\\\m=\dfrac{Q}{c\Delta T}\\\\m=\dfrac{42.2 }{0.89\times (31.5-25)}\\\\m=7.29\ g[/tex]

So, the mass of the piece is equal to 7.29 grams.

Answer:

Need to find moles NaCl.

526 grams NaCl (1 mole NaCl/58.44 grams)

= 9.0 moles NaCl

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

now,

Molarity = moles of solute/Liters of solution

or, for our purposes

Liters of solution = moles of solute/Molarity

Liters of solution = 9.0 moles NaCl/3.0 M

= 3.0 liters in volume

Answer:

Meaning, Advantages & Disadvantages of - Osmosis, Multiflash Distillatiob

Explanation:

Advantages - It assists equalising concentration of solute on two sides of membrane. Reverse Osmosis is used for efficient water softening, it is easy to maintain.

Disadvantages - It needs a lot of energy. A lot of pressure is required for deionisation. Water acidity level increases, as minerals get deionised.

Advantages - Its Cost efficient , distillation uses waste heat. It has High gain output ratio. Quality of feedwater is less significant, compared to reverse osmosis.

Disadvantages - It has high operating cost in case of waste heat unavailability. High temperature imply high corrosion & scale formation.

Answer:

C

Explanation:

NP

Answer:

Kp = 7.4727

Explanation:

Let's write the balanced equilibrium reaction:

2NH₃ <-------> N₂ + 3H₂     Kp = ??

Now, if we want to calculate the Kp, we need to write an ICE chart with this reaction, which is the following:

         2NH₃ <-------> N₂ + 3H₂  

I.         4,5                 0        0

C.       -2x                +x     +3x

E.        4,5-2x            x       3x

According to this chart, the Kp expression should be:

Kp = (PH₂)³ * (PN₂) / (PNH₃)²   (1)

The value of x, we already know it because the problem states that the amount of nitrogen gas is 1.1 atm, so replacing this value into (1) we have:

Kp = (3*1.1)³ * (1.1) / (4.5 - (2 * 1.1))²

Kp = 39.5307 / 5.29

Hope this helps

Answer:

The answer is B

Brainliest please!

Answer: 2.20 g Pb

They gave us the masses of two reactants and asked us to determine the mass of the product. We will need a chemical equation with masses and molar masses, so, let's gather all the information in one place.

Mᵣ:       239.27   32.00        207.2

           2PbS   +   3O₂   ⟶  2Pb   +   2SO₃

m/g:      2.54        1.88

Answer:

12 moles sodium= 275.87724000000003 grams

Explanation:

1 moles sodium = 0.043497607849056.

Answer:

[tex][H^+]=1.78x10^{-8}M[/tex]

Explanation:

Hello there!

In this case, according to the given information about the pH, it is firstly necessary for us to remember that the pH is defined as the potential of the hydrogen ions in the solution and the concentration of those ions represents how many of them are present in the solution; in such a way, it is possible for us use:

[tex]pH=-log([H^+])[/tex]

Whereas the concentration of hydrogen ions can be calculated as follows:

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

So we plug in the given pH to obtain:

[tex][H^+]=10^{-7.75}=1.78x10^{-8}M[/tex]

Regards!

Answer:

2.35x10²³ molecules of C2Cl4 are present

Explanation:

To solve this question we must convert, as first, the mass of C2Cl4 to moles using its molar mass (C2Cl4 = 165.83g/mol). Then, using Avogadro's number we can find the number of molecules:

Moles C2Cl4:

73.1g * (1mol / 165.83g) = 0.441 moles C2Cl4

Molecules:

0.441 moles C2Cl4 * (6.022x10²³molecules / 1mol) =

Answer:

What is

the volume of the balloon when the temperature is 310K?

Answer:

pH = 4.6

Explanation:

As hydrochloric acid (HCl) is a strong acid, the molar concentration of H⁺ species is the same as the molar concentration of the HCl solution. In other words:

With the information above in mind we can calculate the pH: