Use the observations about each chemical reaction in the table below to decide the sign (positive or negative) of the reaction enthalpy AH and reaction entropy
AS.
Note: if you have not been given enough information to decide a sign, select the "unknown" option.

Answer:

The density of water is about 1.0 g/mL at room temperature.

Briefly explain how the density of an aqueous solution at room temperature can be significantly less than 1.0 g/mL.

Give an example of such a solution.

Explanation:

That means 1.0mL of water weighs ---- 1.0g

If any other aqueous solution which has mass less than 1.0g will have density less than 1.0g.

For example aqueous solution of sulfuric acid has density 0.98g/mL.

That means 1mL of sulfuric acid has mass 0.98g.

Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water, for example, sulfuric acid which has a density 0.98g/mL.

The density of a substance is the ratio of the mass to the volume of that substance.

Density measures compactness.

More compact substances are more dense.

The density of water is about 1.0 g/mL at room temperature.

This means that 1.0mL of water weighs 1.0g

1.0 mL of an aqueous solution whose mass is less than 1.0g will have density less than that of water.

Dissolving gases or liquids in water whose density are less than that of water will result in an aqueous solution whose density is less than that of water.

An example of an aqueous solution whose density is less than that of water is sulfuric acid which has a density 0.98g/mL.

Sulfuric acid is prepared by dissolving sulphur (vi) oxide, a gas, in water.

This means 1mL of sulfuric acid has mass 0.98g.

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Answer:

68.97g of milk must be added

Explanation:

To solve this problem we need to use the equation:

Q = C*m*ΔT -Coffee cup calorimeter equation-

This equation relates mass and change in temperature with heat of solution, Q.

The energy that decreases in the milk is the same that increases in the milk. That is:

Q(milk) = Q(tea)

Using the equation:

4.184J/molK* Mass milk * (65.0°C - 7.00°C) = 4.184J /molK * 200g (Tea) * (85.0°C - 65.0°C)

Mass milk * 58.0°C = 200g * 20.0°C

Mass milk = 4000g°C / 58.0°C

Mass milk =

68.97g of milk must be added

Answer:

Examples. Glucose (C6H12O6), ribose (C5H10O5), Acetic acid (C2H4O2), and formaldehyde (CH2O) all have different molecular formulas but the same empirical formula: CH2O.

Explanation:In chemistry, the empirical formula of a chemical compound is the simplest positive integer ratio of atoms present in a compound.

Answer:

Decrease temperature or reduce pressure

Answer:

4.7 g

Explanation:

The reaction that takes place is:

First we convert 4.8 g of CaCl₂ into moles, using its molar mass:

Then we convert CaCl₂ moles into Na₃PO₄ moles, using the stochiometric coefficients of the balanced reaction:

Finally we convert 0.0288 moles of Na₃PO₄ into grams, using its molar mass:

Answer:

Explanation:

The molar mass of a given substance corresponds and pertains to the unit mole of the mass substance which is stated in g/mol

no of moles of H = mass of H/molar mass of H

= 2 kg/ 2 g/mol

= 2000 g/ 2 g/mol

= 1000 moles

moles of O2 = mass (O2)/ molar mass (O2)

= 2 kg/ 32 g/mol

= 2000 g / 32 g/mol

= 62.5 moles

Total moles present = (1000 + 62.5) moles

= 1062.5 moles

= 1.063 kmol

Total mass = 2kg + 2kg

= 4 kg

no of moles = mass/molar mass

molar mass = mass/ no of moles

molar mass = 4 kg/ 1.063 kmol

molar mass = 3.763 kg/kmol

The specific volume of the final mixture can be determined by the relation:

[tex]v_{mixture}=\dfrac{ V}{m}[/tex]

where;

V = 3 m³

m = 4 kg

[tex]v_{mixture}=\dfrac{ 3 \ m^3}{4 \ kg}[/tex]

= 0.75 m³/ kg

For the final volume, The molar specific volume is:

[tex]v_M = M_{mixture} *v_{mixture}[/tex]

where;

[tex]M_{mixture} = 3.763[/tex]

[tex]v_{mixture} = 0.75 \ m^3/ kg[/tex]

∴

[tex]v_M = 3.763 \ kg/mol \times 0.75 \ m^3/kg[/tex]

[tex]\mathbf{v_M = 2.82 \ m^3/kmol}[/tex]

Answer:

Ph level 0-7 is a acid

ph level 7-14 is base

bases turn paper blue

acids dissolve metal

acids contain hydrogen ions

Explanation:

I dont know the last one all I know that they become neutral when acids and bases are mixed.

Answer:

The correct answer is - A. ammonia blue.

Explanation:

It is given that there is a mixture of ammonium chloride and sodium hydroxide and if we heat the  Mixture of NH4Cl and NaOH then, the following reaction will take place-

NH4Cl (aq)+ NaOH (aq)==> NaCl (aq) + NH3 (g)+ H2O (l)

In this reaction, there is a release of NH3 gas which is absorbed on litmus paper. We know that NH3 gas is basic in nature and so it will turn litmus paper blue.

Thus, the correct answer would be - NH3 (ammonia ) and Blue

Answer:

Phenols do not exhibit the same pka values as other alcohols;

They are generally more acidic.

Using the knowledge that hydrogen acidity is directly related to the stability of the anion formed, explain why phenol is more acidic than cyclohexane.

Explanation:

According to Bromsted=Lowry acid-base theory,

an acid is a substance that can release [tex]H^{+}[/tex] ions when dissolved in water.

So, acid is a proton donor.

If the conjugate base of an acid is more stable then, that acid is a strong acid.

In the case of phenol,

the phenoxide ion formed is stabilized by resonance.

[tex]C_6H_5OH -> C_6H_5O^- +H^+[/tex]

The resonance in phenoxide ion is shown below:

Whereas in the case of cyclohexanol resonance is not possible.

So, cyclohexanol is a weak acid compared to phenol.

Answer:

The Cell Wall

Explanation:

Answer:

See explanation.

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to realize that the NaCl solution must react with an aluminum-containing substance, say the hydroxide or any other salt, so that the following equation will take place:

[tex]3NaCl(aq)+Al^{3+}\rightarrow 3Na^+(aq)+AlCl_3(s)[/tex]

In such a way, given the volume of the NaCl solution, it must be necessary to know its concentration, in order to get moles of this salt, further use the 3:1 mole ratio of NaCl to AlCl3 and the molar mass of the latter (133.34 g/mol) in order to solve an stoichiometric setup like the following:

[tex]m_{AlCl_3}=V_{NaCl}*M_{NaCl}*\frac{1molAlCl_3}{3molNaCl} *\frac{133.34gAlCl_3}{1molAlCl_3}[/tex]

Besides, you must make sure the volume is in liters.

Best regards!

Answer:

4.3 is your answer because it's matches

Answer:

the 2nd and 5th

Explanation:

they are both correct

Answer:

b and d | Glucose is a reactant in both photosynthesis and cellular respiration. | Carbon dioxide is a product of both photosynthesis and cellular respiration.

Explanation:

hope this helps.

Answer:

NBr3 - Trigonal pyramidal

SO2- Bent

SBr42+- Tetrahedral

SO42- Tetrahedral

CF3Cl - Tetrahedral

Explanation:

The shape of a molecule depends on the number of electron pairs on the valence shell of the central atom in the molecule. This is well captured in the valence shell electron poair repulsion theory.

The number of electron pairs on the outermost shell of the central atom in a molecule are called regions of electron density. According to this theory, these regions of electron density must be positioned as far apart from each other as possible to minimize repulsions between electron pairs.

This theory is the basis of the shapes of molecules shown in the answer. If a molecule has four regions of electron density, it could be trigonal pyramidal or tetrahedral in shape such as NBr3 and CF3Cl.

Note that, when deciding on the three dimensional geometry of a molecule, only the covalent bonds present are considered.

The average potential energy of water molecules is greatest in in  steam at 100 °C. Potential energy is indeed a characteristic of a system.

Potential energy is stored energy that is affected by the relative location of various components in a system. When a spring is squeezed or extended, its potential energy increases.

Potential energy is indeed a characteristic of a system, not an individual substance or particle; for example, the system made of Earth and the elevated ball has greater potential energy as even the two are separated. Potential energy exists in systems having pieces that exert forces on one another of varying magnitudes based on their configuration, or relative location. The average potential energy of water molecules is greatest in steam at 100 °C.

Therefore, the average potential energy of water molecules is greatest in  steam at 100 °C.

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Answer:

The options are

A) n = 1 → n = 6

B) n = 6 → n = 1

C) n = 6 → n = 3

D) n = 3 → n = 6

E) n = 1 → n = 4

The answer is A) n = 1 → n = 6

The transition results in the absorption of the highest-energy photon. This is because absorption typically involves the movement from a lower energy state to a higher level.

The answer here is B as a result of it being the option which moves from a lower state to a higher state with a bigger margin than the rest.

Answer:

CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl

Explanation:

Alkanes react with halogens in the presence of light to yield alkyl halides. The degree of substitution increases as the reaction progresses. The reaction occurs by free radical mechanism.

The reaction between butane and chlorine molecule to yields a monosubstitution product occurs as follows;

CH3CH2CH2CH3 + Cl2 --------> CH3CH2CH2CH2Cl + HCl

Answer:

Research that releases a poisonous gas into the air.

Explanation:

Since I don't know the options I will guess it is ^

The symbol of the element in which it's ion has 38 protons, 36 electrons, and 40 neutrons is ⁷⁸₃₈Sr

To obtain the symbol of the element, we shall obtain the mass number of the element. This is shown below:

Mass number = Proton + Neutron

Mass number = 38 + 40

Mass number = 78

Finally, we shall determine the symbol of the element. Details below:

From the periodic table, the element with atomic number of 38 is Strontium.

Thus, the symbol of the element will be ⁷⁸₃₈Sr

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Answer:

Ca(ClO3)2

Explanation:

The chemical formula of calcium chlorate is Ca(ClO3)2, which means in this molecule, Ca2+ ion is bonded to two ClO3- ions. So the formula can be expended to O3Cl-Ca-ClO3, or CaCl2O6 (basically times the numbers of the elements inside the bracket by the number outside the bracket.

Solution :

A cell that is concentrated is constructed by the same half reaction for the anode as well as he cathode.

We know,

In a standard cell,

the reduction half cell reaction is :

[tex]$Ag^+(aq)+e^- \rightarrow Ag(s) E^0 = -0.80 \ V$[/tex]

The oxidation half ell reaction :

[tex]$Ag(s) \rightarrow Ag^+(aq) + e^- \ E^0= +0.80 \ V$[/tex]

Thus the complete reaction of the cell is :

[tex]$Ag^+(aq)+ Ag(s) \rightarrow Ag^+(aq)+Ag(s)$[/tex]

[tex]$E^0 $[/tex] cell = [tex]$E_R - E_L = 0.00 \ \text{volts}$[/tex]

Answer:

Explanation:

Both extraction and wash are technical materials separation processes. Both seek to carry out a separation of liquid-liquid, through the relationship between solvent and solute present in this solution. Both use a separation funnel and are very similar processes where the main difference is the purpose that each one seeks to exercise. The extraction causes the dissolution of the material that the researcher wants to leave behind. this process leaves impurities in the initial solution layer and moves the researcher's desired compound to the second layer of solution. A chemical reaction can take place during this process.

A wash, on the other hand, dissolves all impurities from the solution and extracts the compound desired by the researcher. Therefore, we can conclude that during this process the impurities are moved from one layer to another in the solution until it is discarded from the funnel, leaving the desired compound in the initial layer.

Answer:

it will be no. A that is thereis hydrogen bonding H2 molecules and between H2O molecules

Answer:

Electronegativity (EN): A measure of an atom's ability to attract electrons (or electron density) toward itself.

Atomic Radius(R) is defined as one-half the distance between the nuclei of identical atoms that are bonded together.

Ionization Energy is the minimum amount of energy required to remove the most loosely bound electron of an isolated neutral gaseous atom or molecule.

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Answer:

V1 = 8.3 mL

Explanation:

Step 1: Given data

Initial volume (V1): ?

Initial concentration (M1): 6.0 M

Final volume (V2): 50.0 mL

Final concentration (M2): 1.0 M

Step 2: Calculate the volume of the initial solution

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

M1 × V1 = M2 × V2

V1 = M2 × V2 / M1

V1 = 1.0 M × 50.0 mL / 6.0 M = 8.3 mL

We will take 8.3 mL of the 6.0 M solution and add water until we have 50.0 mL.

Answer:

6.33×10¯²² g

Explanation:

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

Number of atoms = 6 atoms

Mass of copper (Cu) =?

From Avogadro's hypothesis, we understood that:

6.02×10²³ atoms = 1 mole of Cu

But 1 mole of Cu = 63.5 g

Thus,

6.02×10²³ atoms = 63.5 g of Cu

Finally, we shall determine the mass of 6 atoms of copper. This can be obtained as illustrated below:

6.02×10²³ atoms = 63.5 g of Cu

Therefore,

6 atoms = (6 × 63.5) / 6.02×10²³

6 atoms = 6.33×10¯²² g of Cu

Therefore, the mass of 6 atoms of copper is 6.33×10¯²² g.

Answer:

1 Spinal fluid

2 Milk

3 Saliva

4 Urine

5 Gastric content

Explanation:

Hello there!

In this case, according to the given information, it turns out firstly necessary for us to calculate the pH of both gastric content and spinal fluid by using the following equations and works:

[tex]pH_{gastric}=-log(10^{-2})=2.0\\\\pH_{spinal}=14+log(10^{-6.6})=7.4[/tex]

Thus, we rank them as follows:

1 Spinal fluid

2 Milk

3 Saliva

4 Urine

5 Gastric content

Regards!

Answer:

True

Explanation:

hope this helps mate