How many grams of Br are in 445 g CaBr2 ?

Answer:

0.0002949 moles

Explanation:

Concentration = 2.02×10−2 M

Volume = 14.6 mL = 0.0146 L (Upon converting to litres)

Number of moles = ?

These variables are related by the fllowing equation;

Concentration = Number of moles / Volume

Number of moles = Concentration * Volume

Number of moles = 2.02×10−2 * 0.0146 = 0.0002949 moles

Answer:

A divergent plate boundary  

Explanation:

At a divergent boundary, the plates pull away from each other and generate new crust.

Answer:

Because the ocean becomes larger, this is a divergent plate boundary. Divergent plates cause the ocean floor to expand, making the ocean larger.

Explanation:

PLATO ANSWER

Answer:

16G = 1 mole ; then 4G = how many moles? 4/16 = 0.25 mole; That means 4 grams of oxygen is 0.25 moles.

Explanation:

A mole of water molecules contains 2 moles of hydrogen atoms and 1 mole of oxygen atoms.

Answer:

True

Explanation:

The percentage by mass of a substance in a solution can be calculated by dividing the mass of the substance dissolved in the solution by the total mass of the solution. This can be expressed mathematically as:

Percentage by mass = mass of substance in solution/mass of solution x 100

In this case;

mass of KBr = 4.34 grams

mass of water = 17.4 grams

mass of solution = mass of KBr + mass of water = 4.34 + 17.4 = 21.74

Percentage by mass of KBr = 4.34/21.74 x 100

                                              = 19.96 %

19.96 is approximately 20%.

Hence, the statement is true.

Answer:

Number of mole in Oxygen = 2.24 mol

Explanation:

Given:

Amount of carbon dioxide (CO₂) = 49.2 gram

Find:

Number of moles in Oxygen

Computation:

Molecular weight of CO₂ = 44 gram (Approx)

Number of mole in CO₂ = 49.2 / 44

Number of mole in CO₂ = 1.11818182 mol

CO₂ has 2 mole of Oxygen,

So,

Number of mole in Oxygen = 2 × 1.11818182

Number of mole in Oxygen = 2.23636364

Number of mole in Oxygen = 2.24 mol

Answer:

All of the above

Explanation:

Proteins contain a long chain of amino acids which are a chain of oxygen, nitrogen, carbon, hydrogen or sulfur.

HOPE THIS HELPED

Answer:

there are 37,8541 liters in 10 gallons

Answer:

It will react with water

Explanation:

I know this is an older question, but I just wanted to provide the correct answer.

Since we are dealing with a weak base, and the acid is somewhat stronger, it will react with the water molecules to produce hydronium, which will affect the pH of the solution.

The conjugate base of a weak acid affect pH because it will react with hydronium ion.

A weak acid is an acid that does not dissociate completely in water. On the other hand, a strong acid achieves almost 100% dissociation in water.

Acids dissociate in water to yield the hydronium ion and a conjugate base. For instance, the weak acid, acetic acid is dissociated as follows;

CH3COOH(aq) + H2O(l) ⇄ CH3COO-(aq) + H3O+(aq)

We can see that the conjugate base( CH3COO-) could react with the hydronium ions thereby moving the equilibrium position to the left hand side and affecting the pH by decreasing the hydronium ion concentration.

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Missing parts;

Why will the conjugate base of a weak acid affect pH? Select the correct answer below: O it will react with hydroxide O it will react with water O it will react with hydronium O none of the above

The correct answer is C. square planar

According to the Valence Shell Electron Pair Repulsion Theory(VSEPR), The shape of a molecule depends on the number of electron pairs in the molecule.

VSEPR theory was first coined by Gillespie  and Nyhlom in 1957 as an improvement over the Sidgwick - Powell theory.

According to this theory, the shape of a molecule is determined by the number of electron pairs that surround the valence shell of the central atom in the molecule.  The electron pairs are positioned as far apart in space as possible to minimize repulsion of electron pairs.

However, the presence of lone pairs distorts the shape anticipated for the molecule on the basis of VSEPR.

For a molecule having six electron pairs, an octahedral geometry is expected(electron domain geometry). However, the presence of two lone pairs which are positioned at opposite side of the four single bonds leads to an observed square planar molecular geometry.

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Answer:

square planar

Explanation:

Answer:

d. condensation of water on a wind shield of a car

Explanation:

Condensation involves the conversion of moist air into liquid.

Gas has a higher energy compared to liquid. This is why Gas particles move at random motion and faster in relation to solid and liquid particles due to the high energy content.

The conversion of the gas to liquid means that there was loss or release of energy which validates the answer.

Answer:

Eªcell > 0; n = 2

Explanation:

The reaction:

I2 (s) + Pb (s) → 2 I- (aq) + Pb2+ (aq)

Is product favored.

A reaction that is product favored has ΔG < 0 (Spontaneous)

K > 1 (Because concentration of products is >>>> concentration reactants).

Eªcell > 0 Because reaction is spontaneous.

And n = 2 electrons because Pb(s) is oxidizing to Pb2+ and I₂ is reducing to I⁻ (2 electrons). Statements that are true are:

Answer:

Animals whose certain organs closely match those of humans or have similar genetic makeup are used in vaccine tests because the results can closely resemble those same results on humans.

Explanation:

Answer:

they use them to test the effectiveness of the vaccine.

Explanation:

Answer:

Reaction of Chlorine with Hydrogen Chlorine and Hydrogen mixed together explodes when exposed to sunlight, which produces Hydrogen Chloride. In the dark away from sunlight, no reaction occurs, so light energy is required for a reaction. Cl2 + H2 = 2 HCl Reaction of Chlorine with Non-Metals Chlorine directly combines with most non-metals.

Explanation:

I hope this helps bro

Answer:

Bakelite is a polymer made up of the monomers phenol and formaldehyde. This phenol-formaldehyde resin is a thermosetting polymer.

Answer: The monomers of bakelite are formaldehyde and phenol

Explanation:

#c

[tex]\\ \rm\hookrightarrow H_2PO_4^-+OH-\longrightarrow HPO_4^{2-}+H_2O[/tex]

#2

[tex]\\ \rm\hookrightarrow C_5H_5N+C_2H_4O_2\longrightarrow C_6H_6N^++C_2H_3O_2^-[/tex]

The given question is incomplete, the complete question is:

An atom of 122In has a mass of 121.910280 amu. Calculate the binding energy in MeV per atom. Use the masses: mass of 1H atom = 1.007825 amu mass of a neutron = 1.008665 amu 1 amu = 931.5 MeV

Answer:

The correct answer is 1029.95 MeV.

Explanation:

Based on the given information,  

The mass of proton is 1.007825, the mass of neutron is 1.008665.  

The atomic number of Indium is 49, therefore, the number of neutrons will be, 122-49 = 73.  

Now the calculated mass will be,  

= 49 * 1.007825 + 73 * 1.008665

= 49.383425 + 73.632545

= 123.01597

The mass defect is calculated by subtracting the actual mas from calculated mass,  

Mass defect = Actual mass - Calculated mass

= 121.910280 - 123.01597

= -1.10569 amu

Now the binding energy will be,  

Binding energy = 1.10569 * 931.5 MeV

= 1029.95 MeV

Answer:

(D) The reaction cannot take place in a single elementary step

Explanation:

Statements are:

(A) The time it takes for [CH3I] to decrease to 0.005 M is independent of [N3-], as long as [N3] >> [CH3I].

B) If the initial concentrations of azide and CH3I are equal, then it takes half as long for [CH3I] to decrease to 0.005 M as it does for it to decrease from 0.005 M to 0.0025 M.

(C) The reaction rate is significantly smaller if excess I- is added to the solution.

(D) The reaction cannot take place in a single elementary step.

The rate of the reaction is:

rate = k[CH3I][N3–].

That means rate depends of concentration of CH₃I as much as N₃⁻ concentration

(A) The time it takes for [CH3I] to decrease to 0.005 M is independent of [N3-], as long as [N3] >> [CH3I]. FALSE. The reaction rate depends of N₃⁻ as much as CH₃I

B) If the initial concentrations of azide and CH3I are equal, then it takes half as long for [CH3I] to decrease to 0.005 M as it does for it to decrease from 0.005 M to 0.0025 M. FALSE. Reaction is second-order. Half-life is 1/K[A]₀. If initial concentration is 0.1M, to a concentration of 0.005M it takes:

1/K*0.1. If initial concentration is 0.005M it takes 1/K*0.005. That means it takes half to decrease from 0.005M to 0.0025 as it does for it to decrease from 0.01M to 0.005M.

(C) The reaction rate is significantly smaller if excess I- is added to the solution. FALSE. Reaction rate is independent of I⁻

(D) The reaction cannot take place in a single elementary step. TRUE. As this reaction is a single-replacement reaction implies the formation  of 1 C-N bond. But also the rupture of the C-I bond is impossible to explain this kind of reaction in a single elementary step.

Answer:

Writing a balanced Equation for the reaction

Br₂ + 3Cl₂ ==> 2BrCl₃

Kc = [BrCl₃]² / [Br₂][Cl₂]³

Each Concentration (n) = moles/volume of container.

(nBrCl₃)= 1/6 = 0.167moldm-³

(nBr₂) = 2/6 = 0.333moldm-³

(nCl₂) = 6/6 = 1moldm-³

Kc = (0.167)² / (0.333)(1)³

Kc = 0.0838.

Answer:

0.500 moles of oxygen

Explanation:

Full question says: "Calculate the moles of oxygen needed to produce 0.500 moles of acetic acid.

The reaction of ethanol (C₂H₅OH) with oxygen (O₂) is:

C₂H₅OH + O₂ → CH₃COOH + H₂O

Where 1 mole of ethanol reacts per mole of oxygen to produce 1 mole of acetic acid (CH₃COOH) and 1 mole of water

Based on the chemical equation (1 mole of oxygen produce 1 mole of acetic acid; Ratio 1:1). Thus, if you want to produce 0.500 moles of acetic acid you will need:

Answer:

Explanation:

This is a bit of a trick question.

Usually an exothermic reaction is written as

A + B - heat = C + D

The meaning of this equation is that when the bonds of the reactants break, heat has to be given away to the environment. On the left, exothermic means that heat has to be given.

The wording on this question means that heat is a product

A + B = C + D + heat.

In other words heat is given up to the environment. So this reaction is exothermic.

Answer:

The correct answer is 0.186 V

Explanation:

The two hemirreactions are:

Reduction: Fe²⁺ + 2 e- → Fe(s)  

Oxidation : Co(s)  → Co²⁺ + 2 e-

Thus, we calculate the standard cell potential (Eº) from the difference between the reduction potentials of cobalt and iron, respectively,  as follows:

Eº = Eº(Fe²⁺/Fe(s)) - Eº(Co²⁺/Co(s)) = -0.28 V - (-0.447 V) = 0.167 V

Then, we use the Nernst equation to calculate the cell potential (E) at 298.15 K:

E= Eº - (0.0592 V/n) x log Q

Where:

n: number of electrons that are transferred in the reaction. In this case, n= 2.

Q: ratio between the concentrations of products over reactants, calculated as follows:

[tex]Q = \frac{ [Co^{2+} ]}{[Fe^{2+} ]} = \frac{0.33 M}{1.47 M} = 0.2244[/tex]

Finally, we introduce Eº= 0.167 V, n= 2, Q=0.2244, to obtain E:

E= 0.167 V - (0.0592 V/2) x log (0.2244) = 0.186 V

Answer:

length

Explanation:

edge 2020

hope this helps!

Answer:

A.) Density

Explanation:

Correct on edge.

Answer:

CH4 < CH3CH3 < CH3CH2CH3

Explanation:

Alkanes are saturated aliphatic hydrocarbons that undergoes intermolecular Van der waals forces. Van der waals forces are the attractive forces which make it possible for non-polar molecules to form liquids and solids.

Van der waals force are described as intermolecular forces arising from induced fluctuating dipoles in atoms and molecules brought about by movement of electrons around the atomic nucleus.

An example of the Van der waals force is the  london dispersion force that occurs in the alkane family. It is the weakest of all electrical forces that act between atoms and molecules, These forces are responsible for liquefaction or solidification of non-polar substances at low temperature.

The strength of the intermolecular forces is based on the number of electrons surrounding the molecule and the surface area of the molecule. SO, in alkanes, the longer the carbon chain, the more stronger the intermolecular forces.

Answer:

b. the amount of heat given off or absorbed

Explanation:

Hello,

In this case, we should take into account a formal definition of enthalpy change such as an energetic change that occurs in a system when matter is transformed by a given chemical reaction from reactants to products. Thus, such energetic change is macroscopically exhibited and it is related with either a temperature increase or decrease; it means that if a reaction exhibits a temperature increase, we say that heat was given off and if the temperature exhibits a decrease, we say that heat is absorbed. For that reason, answer is b. the amount of heat given off or absorbed.

Regards.

Answer:

1. Exothermic 2.  Exothermic 3. Endothermic 4. Endothermic 5. Exothermic.

Explanation:

1. An A-A and a C-C bond results in 2 A-C bonds which are lower than the A-A and C-C bonds so this reaction is exothermic.

2. A B-B bond and a C-C bond results in 2 B-C bonds which are lower than the first 2 bonds so this reaction is also exothermic.

3. There is no bond for single A, a single B-C bond results in a A-B bond and a C molecule. A-B bond is stronger than the B-C bond so the reaction absorbed energy along the way. This shows that it is endothermic.

4. An A-A bond and a B-B bond results in 2 A-B bonds which are stronger than the first two bonds so this reaction is also endothermic.

5. An A-B bond and a C molecule result in an A-C bond and a B molecule. A-C bond is weaker than the A-B bond so there is energy released. This reaction is exothermic.

I hope this answer helps.

Answer:

A. as an agglomeration metal

B. as a native metal

D. in sulfide ore minerals

Explanation:

Copper is a metal with symbol Cu and atomic number 29. It has a pinkish-orange color and is malleable, ductile and has a high thermal and electrical conductivity. This is why it is often used in electrical appliances.

Copper exists as an agglomeration metal, as a native metal or in sulfide ore minerals such as Cu2S.

The examples of copper deposits are  agglomeration metal, as a native metal or in sulfide ore minerals. Option A, B, and D are correct.

Copper is a metal with high thermal and electrical conductivity. hence, it is often used in electrical appliances.

Copper found as an agglomeration metal, as a native metal or in sulfide ore minerals such as [tex]\bold { Cu_2S.}[/tex]

Therefore, the examples of copper deposits are  agglomeration metal, as a native metal or in sulfide ore minerals. Option A, B, and D are correct.

To know more about agglomeration metal,

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Answer:

pH = 13.7

Explanation:

A strong acid (HCl) reacts with a strong base Sr(OH)₂ producing water and a salt, thus:

2HCl + Sr(OH)₂ → 2H₂O + SrCl₂

To solve this problem, we need to find initial moles of both reactants and, with the chemical equation find limiting reactant and moles in excess to find pH as follows:

The initial moles of HCl and Sr(OH)₂ are:

100mL = 0.1L ₓ (1.0mol / L) = 0.100 moles of both HCl and Sr(OH)₂

As 2 moles of HCl reacts per mole of Sr(OH)₂, moles of Sr(OH)₂ that reacts with 0.100 moles of HCl are:

0.100 moles HCl ₓ (1 mol Sr(OH)₂ / 2 mol HCl) = 0.050 moles Sr(OH)₂

That means HCl is limiting reactant and after reaction will remain in solution:

0.100 mol - 0.050mol =

0.050 moles of Sr(OH)₂

Find pH:

1 mole of Sr(OH)₂ contains 2 moles of OH⁻, 0.050 moles contains 0.050×2 = 0.100 moles of OH⁻. In 200mL = 0.2L:, molar concentration of OH⁻ is:

0.100 moles / 0.2L =

[OH⁻] = 0.5M

As pOH of a solution is -log[OH⁻],

pOH = -log 0.5M

pOH = 0.301

And knowing:

pH = 14 - pOH

pH = 14 - 0.301

Answer:

A)coupling between 1H nuclei attached to adjacent C atoms.

Explanation:

The word ‘vicinal’ in chemistry means three bonds from the functional groups. The two functional groups are in a relationship with the atoms in adjacent position to them.

The 1H nuclei consists of two Hydrogen nucleus which acts as the functional groups. They are however attached and in a relationship with the adjacent C atoms. This makes option A the right choice.

Answer:

The correct answer is : option D. The test was inconclusive because he forgot to add heat.

Explanation:

Benedict's test is a test that is used to confirm the presence of the simple carbohydrates (mono saccharides and some disaccharides). It is a reagent made by mixture of solution of CuSO4 with sodium citrate and Na2CO3.

Benedict's reagent is added to the substance to test and then heated if it turns yellow to orange or red the presence of simple sugar is confirmed.

Thus, the correct answer is : option D. The test was inconclusive because he forgot to add heat.

Answer:

The test was inconclusive because the student forgot to add heat.

Explanation:

If the test revealed it was not glucose, then the student could run these tests. The student, however, does not need these substances to run the glucose test properly.

Answer:

The correct answer is CaO > LiBr > KI.

Explanation:

Lattice energy is directly proportional to the charge and is inversely proportional to the size. The compound LiBr comprises Li+ and Br- ions, KI comprises K+ and I- ions, and CaO comprise Ca²⁺ and O²⁻ ions.  

With the increase in the charge, there will be an increase in lattice energy. In the given case, the lattice energy of CaO will be the highest due to the presence of +2 and -2 ions. K⁺ ions are larger than Li⁺ ion, and I⁻ ions are larger than Br⁻ ion.  

The distance between Li⁺ and Br⁻ ions in LiBr is less in comparison to the distance between K⁺ and I⁻ ions in KI. As a consequence, the lattice energy of LiBr is greater than KI. Therefore, CaO exhibits the largest lattice energy, while KI the smallest.  

Arranging the chemical compounds in order of decreasing magnitude of lattice energy, we have:

c. CaO.

a. LiBr

b. KI

Lattice energy can be defined as a measure of the energy required to dissociate one (1) mole of an ionic compound into its constituent anions and cations, in the gaseous state.

Hence, it is typically used to measure the bond strength of ionic compounds.

Generally, lattice energy is inversely proportional to the size of the ions and directly proportional to their electric charges.

Lithium bromide (LiBr) comprises the following ions:

Potassium iodide (KI) comprises the following ions:

Calcium oxide (CaO) comprises the following ions:

From the above, we can deduce that there is an increase in the charge possessed by the ionic chemical compounds and as such this would result in an increase in the lattice energy.

In order of decreasing magnitude of lattice energy, the chemical compounds are arranged as:

I. CaO.

II. KI.

III. LiBr.

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