Consider the balanced chemical equation below.

2 A ⟶ C + 4 D

How many moles of D would be produced if 6 moles of A were used?

Answer:

The correct option is D (KBr)

Explanation:

Potassium bromide (KBr) is a typical example of an IONIC CRYSTAL. Positive and negative ions are arranged in a regular pattern to give a giant crystal lattice in an ionic solid.

Ionic crystals are hard and have high melting points because the electrostatic forces holding the ions are strong. In the solid state, ionic compounds are poor conductors of electricity because the ions are held rigidly in place and so cannot moves about.

When melted or when dissolved in water, the ions are free to move about and the ionic substances become good conductors of electricity.

Ionic crystals are also BRITTLE. When struck, they tend to shatter because as planes of ions slip by one another, they pass from a condition of mutual attraction to one of mutual repulsion.

Answer:

NH3 Ammonia

Explanation:

Ammonia has 4 regions of electron density around the central nitrogen atom (3 bonds and one lone pair). These are arranged in a tetrahedral shape. The resulting molecular shape is trigonal pyramidal with H-N-H angles of 106.7°.

Answer:

HCN, weak acid

H⁺, Br⁻, strong acid

Explanation:

Hydrocyanic acid is a weak acid, according to the following equation.

HCN(aq) ⇄ H⁺(aq) + CN⁻(aq)

Thus, it should be written in the undissociated form (HCN).

Hydrobromic acid is a strong acid, according to the following equation.

HBr(aq) ⇒ H⁺(aq) + Br⁻(aq)

Thus, it should be written in the ionic form (H⁺, Br⁻).

Answer:

About redox reaction which of the given statements are true?

Explanation:

Redox reaction is the one in which both oxidation and reduction reactions take place simultaneously.

For example:

[tex]C(s)+O_2(g)->CO_2(g)[/tex]

In this reaction, carbon undergoes oxidation and oxygen undergoes reduction simultaneously.

During this reaction, mutual exchange of electrosn take place between the oxidant and the reductant.

Among the given options,

Option B. electrons are transferred

and

option C.They include both oxidation and reduction takes place are the correct answers.

Answer:

2.75M

Explanation:

Density = mass/volume

Density of glycerol (C3H8O3) at 15°C is given as 1.2656 g/mL.

Volume of glycerol at this same temperature before dissolving in water = 50mL

Hence, using Density = mass/volume

1.2656 = mass/50

mass = 1.2656g/mL × 50mL

mass = 63.28g

Molarity of solution = number of moles (n) ÷ volume (V)

Volume of glycerol dissolved in water = 250mL = 0.250L

number of moles = mass/molar mass

Molar mass of C3H8O3 = 12(3) + 1(8) + 16(3)

= 36 + 8 + 48

= 44 + 48

= 92g/mol

n = 63.28g ÷ 92g/mol

n = 0.688mol

* Molarity = n/V

Molarity = 0.688/0.250

Molarity = 2.75M

Answer:

Equlibrium concentration for each species ae as follows:

[CO] = 0.043 mol/L

[Br₂] = 0.043 mol/L

[COBr₂] = 0.01 mol/L

Explanation:

Let take a look at the chemical equation taking place at equilibrium

COBr2(g) ⇄ CO(g) + Br2(g)

The concentration of COBr2 i.e.

[COBr2] = no of moles/volume

= 0.50 mol/9.50 L

[COBr2] = 0.0530 mol/L

At standard conditions

Kc for COBr2 = 0.190

Now, the ICE table for the above reaction can be computed as follows:

                       COBr2(g)              ⇄       CO(g)         +           Br2(g)

Initial               0.053                                   0                           0

Change             -x                                       +x                          +x

Equilibrium     (0.053 - x)                              x                           x

[tex]\mathsf{K_c = \dfrac{[CO][Br_2]}{[COBr_2]}}[/tex]

[tex]K_c = \dfrac{(x) (x)}{(0,053 -x)}[/tex]

[tex]0.190= \dfrac{x^2}{(0.053 -x)}[/tex]

x² = 0.190(0.053 - x)

x² = 0.01007 - 0.190x

x² + 0.190x - 0.01007 = 0

Using quadratic formula:

x ≅ 0.043 mol/L

SInce: x = [CO][Br₂] = 0.043 mol/L

[COBr₂] = 0.053 - x

[COBr₂] = 0.053 - 0.043 mol/L

[COBr₂] = 0.01 mol/L

Answer:

qualatatiev is fs-hj_jakakak

Explanation:

Saturated fats are defined as the fat where fatty acid chains contain only single bonds.

For example, stearic acid, palmitic acid etc.

Unsaturated fats are defined as the fat where fatty acids contain one or more number of double bonds on the carbon atoms.

For example, oleic acid, palmitoleic acid etc.

Answer:

Endothermic

Explanation:

Endothermic reaction is one in which the enthalpy increases. What this implies is that, it is a closed system which absorbs heat from its surroundings and thus after reaction become cooler than prior to the reaction.

In this case, the mixture of the two liquids feel colder to touch. Thus, it is an endothermic reaction from the definition earlier given.

Answer:

a) Attached below

b)  The presence of racemic mixture found as product in both  cases shows that   products are identical ( i.e. they have same configuration

Explanation:

Diagrams of the products obtained from hydroboration-oxidation of cis-2-butene , hydroboration-oxidation of trans-2-butene.

attached below

The presence of racemic mixture found as product in both  cases shows that   products are identical ( i.e. they have same configuration )

Answer:

Methane is present in solid, liquid and gaseous form.

Explanation:

Methane hydrate is present in solid state when the hydrogen-bonded water and methane gas come into contact at high pressures and low temperatures in the deep oceans while on the other hand, methane which is present inside the earth surface in gaseous form due to non-availability of water that can combine with methane. Methane is also found in liquid form when it is cool with high pressure and low temperature.

Answer:

oshfjidgshsjdh

Explanation:

918474828

Answer:

The correct answer is "-268.667°C".

Explanation:

Given:

Temperature,

= 4.483 K (below)

Now,

The formula of temperature conversion will be:

⇒ [tex]T(^{\circ} C)=T(K)-273.15[/tex]

By putting the values, we get

⇒            [tex]=4.483-273.15[/tex]

⇒            [tex]=-268.667^{\circ} C[/tex]

Thus the above is the correct answer.

Answer:

[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]

Explanation:

For a hydrogen-like atom, the spectral line wavelength can be computed by using the formula:

[tex]\bar v = Z^2 R_H \Big(\dfrac{1}{n_f^2}-\dfrac{1}{n_i^2}\Big)[/tex]

where:

emitted radiation of the wavenumber  [tex]\bar v[/tex] = ???

atomic no of helium Z = 2

Rydberg's constant [tex]R_H = 1.097*10^7 \ m^{-1}[/tex]

the initial energy of  the principal quantum [tex]n_1[/tex] = 2

the initial energy of  the principal quantum [tex]n_1[/tex] = 2

Now, the emitted radiation of the wavenumber can be computed as:

[tex]\bar v = (2)^2 (1.097*10^7 \ m^{-1} ) \Big(\dfrac{1}{1^2}-\dfrac{1}{2^2}\Big)[/tex]

[tex]\bar v = 3.291 \times 10^ 7/m[/tex]

Now, the wavelength for the transition can be computed by using the relation between the wavelength λ and the emitted radiation of the wavenumber  [tex]\bar v[/tex], which is:

[tex]\bar v = \dfrac{1}{\lambda}[/tex]

[tex]\lambda = \dfrac{1}{\bar v}[/tex]

[tex]\lambda = \dfrac{1}{3.291 \times 10^{7}}\times \dfrac{m}{1}[/tex]

[tex]\mathbf{\lambda =3.03859 \times 10^{-8} \ m}[/tex]

[tex]\mathbf{\lambda \simeq 3.039 \times 10^{-8} \ m}[/tex]

Answer:

True

Explanation:

The length of covalent bond depends upon the size of atoms and the bond order.

Answer:

Explanation:

The mechanism of the reaction is shown in the diagram below. From the reaction, when (2S,3S)-2-Bromo-3-phenylbutane undergoes a reaction with sodium ethoxide (ETONa), the E2 elimination reaction is put into place. Here, the H and the leaving group are antiperiplanar to one another and the reaction mechanism proceeds to form an isomeric (E)-2-phenyl-2butane as the major product.

Answer:

The material properties of nanostructures are different from the bulk due to the high surface area over volume ratio and possible appearance of quantum effects at the nanoscale. ... Yu; they found that the structural distortions on the quantum dots depend both on the kind of dopant and on the size of the dots.

Explanation:

hope it helps

Answer:

90grams

Explanation:

The reaction given in this question is as follows:

2H2 + O2 → 2H20

Based on this equation, 1 mole of oxygen gas (O2) produces 2 moles of water (H2O)

Hence, 2.50moles of oxygen gas will react with excess hydrogen gas to produce (2.5 × 2) = 5.0moles of water.

Using mole = mass/molar mass

Molar mass of water (H2O) = 1(2) + 16

= 18g/mol

5 = mass/18

mass = 18 × 5

mass of H2O = 90grams

Answer:

Pressure increases

Explanation:

Boyle's law states that; '' the volume of a given mass of ideal gas is inversely proportional to its pressure at constant temperature.

Hence, when the volume of a given mass of ideal gas is decreased, the molecules of the gas come closer together so they collide with each other and the walls of the container more frequently.

This implies that the pressure of the gas increases as volume decreases in accordance with Boyle's law.

Answer:

The kinds of intermolecular forces that are present in each element Kr-Kr.

Explanation:

Since Kr is an inert gas and in atomic form only it is highly stable.

So, Kr gas does not form molecules.

Between the atoms of inert gas, there exist London dispersion forces.

Hence, the intermolecular forces that are present between Kr-Kr atoms is London dispersion forces.

Answer:

B

Explanation:

It's the same substance but in different states.

HETEROGENEOUS mixtures contain substances that are

not uniform in composition. The parts in the mixture can be separated by physical means.

Answer:

H2CO

Explanation:

Becuase it has 2 sigma bonds plus one pi bond and one sigma bond that consitute the double bond between C and O.

Answer:

B. H2CO

Explanation:

Answer:

The amount of NO formed s 2.78 moles or 83.4 grams

The amount of H2O formed is 4.17 moles or 75.1 grams

Explanation:

Step 1: Data given

Ammonia = NH3

Oxygen = O2

nitrogen monoxide = NO

water = H2O

Number of moles NH3 = 2.78 moles

Number of O2 = 5.19 moles

Step 2: The balanced reaction

4NH3 + 5O2 → 4NO + 6H2O

Step 3: Calculate moles of products

For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O

NH3 is the limiting reactant

All the NH3 will react. There will be 0 moles of NH3 left

For 4 moles NH3 we need 5 moles O2

For 2.78 moles NH3 we need 5/4 * 2.78 = 3.475 moles

There will be left 5.19 - 3.475 = 1.715 moles O2

For 4 moles NH3 we need 5 moles O2 to produce 4 moles NO and 6 moles H2O

For 2.78 moles NH3 we'll have 2.78 moles NO and 6/4 * 2.78 = 4.17 moles H2O

Step 4: Calculate mass of NO and H2O

Mass = moles * molar mass

Mass NO = 2.78 moles * 30.01 g/mol

Mass NO = 83.43 grams

Mass H2O = 4.17 moles * 18.02 g/mol

Mass H2O = 75.14 grams

The amount of NO formed s 2.78 moles or 83.4 grams

The amount of H2O formed is 4.17 moles or 75.1 grams

Explanation:

here are the answers. Note that because the pressure is constant, you can use Gay Lussac's formula

Answer:

[tex] a = \frac {2A - bh}{h} [/tex]

Explanation:

Given the following mathematical expression;

A = ½(a + b)h

To make a the subject of formula (express a in terms of A, b and h);

First of all, we would cross-multiply;

2A = (a + b)h

Opening the bracket, we have;

2A = ah + bh

Rearranging the mathematical expression, we have;

ah = 2A - bh

[tex] a = \frac {2A - bh}{h} [/tex]

Answer:

Close to the calculated endpoint of a titration - Partially open

At the beginning of a titration - Completely open

Filling the buret with titrant - Completely closed

Conditioning the buret with the titrant - Completely closed

Explanation:

'Titration' is depicted as the process under which the concentration of some substances in a solution is determined by adding measured amounts of some other substance until a rection is displayed to be complete.

As per the question, the stopcock would remain completely open when the process of titration starts. After the buret is successfully placed, the titrant is carefully put through the buret in the stopcock which is entirely closed. Thereafter, when the titrant and the buret are conditioned, the stopcock must remain closed for correct results. Then, when the process is near the estimated end-point and the solution begins to turn its color, the stopcock would be slightly open before the reading of the endpoint for adding the drops of titrant for final observation.

Answer:

1.40x10^24 atoms of H

Explanation: