3. Which of the following can be physically separated?

Answer:

-713 kJ

Explanation:

Step 1: Write the balaned thermochemical equation

4 NH₃(g) + 3 O₂(g) → 2 N₂(g) + 6 H₂O(g)  ΔΗ = -1267 kJ

Step 2: Calculate the moles corresponding to 38.4 g of NH₃

The molar mass of NH₃ is 17.03 g/mol.

38.4 g × 1 mol/17.03 g = 2.25 mol

Step 3: Calculate the  enthalpy change to burn 2.25 mol of ammonia

According to the thermochemical equation, 1267 kJ are released per 4 moles of ammonia that react.

2.25 mol × (-1267 kJ/4 mol) = -713 kJ

Answer:

The Cell Wall

Explanation:

Answer:

What's the equation?

Answer:

14.5 g

Explanation:

its true

Answer:

ee = 96%

Explanation:

Enantiomeric excess, ee, is a way to express a mixture that is not enantiomerically pure. It is defined as 100 times the ratio between the  differences of amounts of enantiomers and the total amunt. that is:

ee = |A-B|/ A+B * 100

ee = |98%-2%| / 98+2 * 100

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:

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:

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.

Answer:

See explanation

Explanation:

Let us look at the reaction again;

Cr2O7 2- (aq) + H2O(l)⇄ 2CrO4 2-(aq) + 2H^+(aq)

When we add sodium hydroxide to the system as shown, the hydroxide ion removes the hydrogen ion thereby leaving a large concentration CrO4^2-(aq) in the system this causes the solution to turn green(equilibrium position shifts to the right).

The net ionic equation is;

OH^-(aq) + H^+(aq) ----> H2O(l)

The reaction;

OH^-(aq) + H^+(aq) ----> H2O(l) is exothermic hence, if the temperature of the system is increased, the equilibrium position will shift towards the left hand side and the solution turns orange.

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:

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:

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.

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

Learn more about symbol:

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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.

Learn more about density at: https://brainly.com/question/406690

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:

cornea,Jens and pupil

tma Po yan

answer is 2546 h

mark me as Branliest

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:

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.

Answer:

59.3g

Explanation:

Mole = no. Molecules/6.02×10^23

Mole = (8.12×10^23)/(6.02×10^23)

Mole = 1.35mole

Molar mass of CO2 = 12+ 2(16)

Molar mass= 12 + 32= 44g/mol

Mole = mass/molar mass

Mass = Mole × molar mass

Mass = 1.35× 44

Mass= 59.35g

Answer:

[tex]pH = - log(7.6 \times {10}^{ - 5} ) \\ pH = 4.12[/tex]

Answer:

Research that releases a poisonous gas into the air.

Explanation:

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

Answer:

128.4 g

Explanation:

Step 1: Given data

Step 2: Determine the total mass of the sample

The mass percent of element X in X(NO₃)₂ is 52.55%, that is, there are 52.55 g of X every 100 g of X(NO₃)₂. Then, the mass of X(NO₃)₂ that contains 67.50 g of X is:

67.50 g X × 100 g X(NO₃)₂/52.55 g X = 128.4 g X(NO₃)₂

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:

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:

True

Explanation:

hope this helps mate