The following statements either define or are closely related to the terms periodic law, period, or group. Match the terms to the appropriate statements.1. This is a vertical arrangement of elements in the periodic table. 2. This is a horizontal arrangement of elements in the periodic table. 3. The properties of the elements repeat in a regular way as the atomic numbers increase. 4. Element 19 begins this arrangement in the periodic table 5. The chemical properties of elements 12, 20, and 38 demonstrate this principle.

Answer:

A = 65.46 u

Explanation:

Given that,

The composition of zinc is as follows :

Zn-64 = 48.63%

Zn-66 = 27.90%

Zn-67 = 4.10%

Zn-68 = 18.75%

Zn-70 = .62%

We need to find the  average atomic mass of the given element. It can be solved as follows :

[tex]A=\dfrac{48.63\times 64+27.90\times 66+4.1\times 67+18.75\times 68+0.62\times 70}{100}\\A=65.46\ u[/tex]

So, the average atomic mass of zinc is 65.46 u.

Answer:

Towards the big bully

Explanation:

If a big bully and a small child are involved in a thug of war, it is clear that the bully is stronger than the child and he/she will pull the rope used in the thug of war with a greater force.

By so doing, the ball attached at the centre of the rope will naturally be drawn towards the stronger bully.

Answer:

In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the axial position and in compound 2 the Tert butyl occupies the axial and the bromine occupies equatorial positions. Compound 1 reacts faster than compound 2.

Explanation:

In cyclic organic compounds, substituents may occupy the axial or equatorial positions. The axial positions are aligned parallel to the symmetry axis of the ring while the equatorial positions are around the plane of the ring.

Bulky substituents have more room in the equatorial than in the axial position. This means that compound 1 is more stable than compound 2.

This is clear on the basis of stability of the molecules because compound 1 will react faster than compound 2 since the bulky tertiary butyl group in compound 1 occupy equatorial and not axial positions.

Answer:

La temperatura final del sistema es 1029,346 °C.

Explanation:

Asumamos que el sistema conformado por el cobre y el estaño no tiene interacciones con sus alrededores. Por la Primera Ley de la Termodinámica, el cobre cede calor al estaño con tal de alcanzar el equilibrio térmico. El cobre se encuentra inicialmente en su punto de fusión, mientras que el estaño está por encima de ese punto, de modo que la transferencia de calor es esencialmente sensible:

[tex]m_{Cu}\cdot c_{Cu}\cdot (T-T_{Cu}) = m_{Sn}\cdot c_{Sn}\cdot (T_{Sn}-T)[/tex]

[tex](m_{Cu}\cdot c_{Cu} + m_{Sn}\cdot c_{Sn})\cdot T = m_{Sn}\cdot c_{Sn}\cdot T_{Sn} + m_{Cu}\cdot c_{Cu}\cdot T_{Cu}[/tex]

[tex]T = \frac{m_{Sn}\cdot c_{Sn}\cdot T_{Sn}+m_{Cu}\cdot c_{Cu}\cdot T_{Cu}}{m_{Cu}\cdot c_{Cu}+m_{Sn}\cdot c_{Sn}}[/tex] (1)

Donde:

[tex]m_{Sn}[/tex] - Masa del estaño, en gramos.

[tex]m_{Cu}[/tex] - Masa del cobre, en gramos.

[tex]c_{Sn}[/tex] - Calor específico del estaño, en calorías por gramo-grados Celsius.

[tex]c_{Cu}[/tex] - Calor específico del cobre, en calorías por gramo-grados Celsius.

[tex]T_{Sn}[/tex] - Temperatura inicial del estaño, en grados Celsius.

[tex]T_{Cu}[/tex] - Temperatura inicial del cobre, en grados Celsius.

Si sabemos que [tex]m_{Cu} = 150\,g[/tex], [tex]m_{Sn} = 35\,g[/tex], [tex]c_{Cu} = 0,093\,\frac{cal}{g\cdot ^{\circ}C}[/tex], [tex]c_{Sn} = 0,060\,\frac{cal}{g\cdot ^{\circ}C}[/tex], [tex]T_{Sn} = 560\,^{\circ}C[/tex] y [tex]T_{Cu} = 1100\,^{\circ}C[/tex], entonces la temperatura final del sistema es:

[tex]T = \frac{(35\,g)\cdot \left(0,060\,\frac{cal}{g\cdot ^{\circ}C} \right)\cdot (560\,^{\circ}C)+(150\,g)\cdot \left(0,093\,\frac{cal}{g\cdot ^{\circ}C} \right)\cdot (1100\,^{\circ}C)}{(35\,g)\cdot \left(0,060\,\frac{cal}{g\cdot ^{\circ}C} \right)+(150\,g)\cdot \left(0,093\,\frac{cal}{g\cdot ^{\circ}C} \right)}[/tex]

[tex]T = 1029,346\,^{\circ}C[/tex]

La temperatura final del sistema es 1029,346 °C.

Answer:

C. Products have higher potential energy, and the reaction is endothermic.

Answer:

The volume of the gas is fixed and will not change.

Explanation:

The volume of the gas will not change because there is no change in temperature. Temperature increases the volume of gases enclosed in a container.

Answer:

No

Explanation:A single property is insufficient for identifying a substance

Answer:

Attached below

Explanation:

Diagram of Bond-line formulas of all monochloro derivatives formed when 1,1-dimethylcyclobutane is allowed to react with c12 under UV

attached below

Explanation:

In the formula of [tex]CaCl_2[/tex] we can see that there are 2mol Cl in 1 molecule of CaCl2. So, now we can do some math to find out how many mol of Cl there are in 1.9mol CaCl2!

[tex]1.9molCaCl_2*\frac{2molCl}{1molCaCl_2}[/tex]

So, there are 3.8mol Cl

Answer:

The explanation as per the given query is presented in the following paragraph.

Explanation:

Thus the above is the correct explanation.

The measured absorbance will be higher, thereby creating systematic error.

In conclusion, the measured absorbance will be higher, thereby creating systematic error.

Learn more in:

https://brainly.com/question/14919298

Answer:

Following are the solution to the given question:

Explanation:

For question a:

It is prevented that the atmospheric [tex]CO_2[/tex] through dissolving in the solution and make carbonic acid [tex](H_2CO_3)[/tex] which reacts with the [tex]NaOH:[/tex]

[tex]CO_2+ H_20\to H_2CO_3\\\\H_2CO_3 + NaOH \to NaHCO_3 +H_2O\\\\H_2CO_3 + 2 NaOH \to Na_2CO_3 + 2H_2O\\\\[/tex]

For question b:

For this, the [tex]NaOH[/tex] reacts with the dissolved [tex]CO_2[/tex]  so, the molarity of the [tex]NaOH[/tex] will be decreased.

For question C:

In this, the Phenolphthalein is pink in the basic solution[tex](high \ pH)[/tex] and colorless throughout the acidic solution[tex](low\ pH)[/tex].

if the solution is exposed  from the atmosphere, the [tex]CO_2[/tex] is from the air dissolving in the solution, and making the [tex]H_2CO_3[/tex] that gives the [tex]H^{+}\ ions[/tex]

[tex]\to[/tex] lower pH.

[tex]\to[/tex] colorless phenolphthalein  

For question D:

[tex]Ba(OH)_2 + 2 HNO_3 \to Ba(NO_3)_2+ 2H_2O\\\\[/tex]

Calculating the moles of[tex]HNO_3 = volume \times \text{concentration of} HNO_3\\\\[/tex]

                                                      [tex]= \frac{25}{1000} \times 0.200\\\\= 0.005\ mol\\\\[/tex]

Calculating the moles of  [tex]Ba(OH)_2= \frac{1}{2} \times\text{moles of}\ HNO_3\\\\[/tex]

                                [tex]=\frac{1}{2} \times 0.005\\\\= 0.0025 \ mol\\\\[/tex]

Calculating the volume of [tex]Ba(OH)_2=\frac{moles}{concentration\ of\ Ba(OH)_2}[/tex]

                                   [tex]=\frac{0.0025}{0.0293}\\\\=0.08532\ L\\\\= 85.32 \ mL\\\\= 85.3\ mL[/tex]

Answer:

The correct answer is - 0.0188 mJ*s^-1.

Explanation:

In order to convert the kPA value to PA value--

and then convert PA unit to 1 kgm^-1s^-2

And in finally convert mm to m

The value that come should be convert from kgm^2s^-2 to and then convert J to mJ or kJ by dividing 100 or 100 subsequently.

As no question given this method can be followed for the answer.

Explanation:

a) Since this is a double displacement reaction, we write the balanced equation as

[tex]2AgNO_3(aq) + CaCl_2(aq) \\ \rightarrow 2AgCl(s) + Ca(NO_3)_2(aq)[/tex]

b) Next we find the number of moles of AgNO3 in the solution.

[tex](0.005\:\text{L})(0.500\:M\:AgNO_3) \\ = 0.0025\:\text{mol}\:AgNO_3[/tex]

Next, use the molar ratio to find the necessary amount of CaCl2 to react with the AgNO3:

[tex]0.0025\:\text{mol}\:AgNO_3× \left(\dfrac{1\:\text{mol}\:CaCl_2}{2\:\text{mol}\:AgNO_3} \right)[/tex]

[tex]= 0.00125\:\text{mol}\:CaCl_2[/tex]

The volume of 0.500 M solution of CaCl2 necessary to react all of the given AgNO_3 is then

[tex]V = \dfrac{0.00125\:\text{mol}\:CaCl_2}{0.500\:\text{M}\:CaCl_2}[/tex]

[tex]= 0.0025\:\text{L} = 2.5\:\text{mL}\:CaCl_2[/tex]

c) The theoretical yield can then be calculated as

[tex]0.0025\:\text{mol}\:AgNO_3 × \left(\dfrac{2\:\text{mol}\:AgCl}{2\:\text{mol}\:AgNO_3} \right)[/tex]

[tex]= 0.0025\:\text{mol}\:AgCl[/tex]

Converting this amount of AgCl into grams, we get

[tex]0.0025\:\text{mol}\:AgCl × \left(\dfrac{143.32\:\text{g}\:AgCl}{1\:\text{mol}\:AgCl} \right)[/tex]

[tex]= 0.358\:\text{g}\:AgCl[/tex]

Answer:

.

Elements are arranged from left to right and top to bottom in the order of their increasing atomic numbers. Thus,

Elements in the same group will have the same valence electron configuration and hence, similar chemical properties.

Whereas, elements in the same period will have an increasing order of valence electrons. Therefore, as the energy level of the atom increases, the number of energy sub-levels per energy level increases.

The first 94 elements of the periodic table are naturally occurring, while the rest from 95 to 118 have only been synthesized in laboratories or nuclear reactors.

The modern periodic table, the one we use now, is a new and improved version of certain models put forth by scientists in the 19th and 20th century. Dimitri Mendeleev put forward his periodic table based on the findings of some scientists before him like John Newlands and Antoine-Laurent de Lavoisier. However, Mendeleev is given sole credit for his development of the periodic table.

Answer:

Water has strong hydrogen bond dipole-dipole intermolecular forces that give water a high surface tension and a high heat of vaporization and that make it a strong solvent

Complete question is;

Identify the type of reaction in the chemical reaction below:

2P205 ➡️ 4P + 502

single replacement

synthesis

decomposition

combustion

double replacement

Answer:

Decomposition

Explanation:

We. An see in the question that the compound 2P205 is broken down into simpler substances which are phosphorus (P) and oxygen (O).

Now, this is a decomposition reaction because a decomposition reaction is one in which a compound is broken down into simpler substances

Answer:

Option A is correct, there will be no N2 left in the flask

Explanation:

Step 1 : Data given

Number of moles of N2 = 135 mmol = 0.135 mol

Number of moles of H2 = 405 mmol = 0.405 mol

Step 2: The reaction

N2(g)+3H2(g)→2NH3(g)

Step 3:

For 1 mol N2 we need 3 moles H2 to produce 2 moles NH3

Both will completely react. There is no limiting reactant.

There will be produce 0.270 moles NH3.

Option A is correct, there will be no N2 left in the flask

The forces in gases are weaker than forces in solids and liquids.

Because they have more kinetic energy that overcomes the force of attraction.

Answer:

Principles of green chemistry:

• Prevent wastes rather than treat them.

• Incorporates all raw materials into the final product.

• Use of synthetic methods.

• To design chemical products to reduce toxicity.

• Use of energy-efficient processes.

• Use of renewable raw materials.

• Reuse chemical intermediates to reduce waste.

• Improve health and safety for staff and customers.

• Cleaner production technologies.

Green chemistry principles can be applied to radioactive wastes by:

• We should choose reagents and procedures that lessen the toxicity and volume of all the wastes. We need to design experiments that radioactive wastes that are produced separately from biologically or chemically hazardous wastes if flexible.

• Substitutes with short-lived radionuclides were feasible.

• Reduce the activity and volumes of wastes generated.

• Limit the number of users of radioactive materials.

• Replace hazardous or mixed wastes.

• Non-radioactive wastes will not be mixed with radioactive wastes. If it is not done then the volume of wastes increases.

C. It can help us track how quickly element of the climate are changing

Answer:

Substrate

Explanation:

In biochemical sciences, a substrate is a substance that is acted upon by an enzyme to yield a product. Enzymes are known for catalyzing biochemical reactions. The substances that are usually worked with during this catalytic process are termed as SUBSTRATES.

Substrates, which are usually changed during the process, binds to the active site on the enzyme and form an enzyme-substrate complex.

According to this question, pyruvate is converted to lactate in a reaction that is catalyzed by the enzyme lactate dehydrogenase. This means that the compound on which the enzyme works, pyruvate, is called the SUBSTRATE.

Explanation:

1.)

mass = 25.04

percentage recovery

[tex]benzoic acid = \frac{10.75}{25.04} = 0.4293*100 = 42.93%\\[/tex]

[tex]naphtalene =\frac{5.41}{25.04} = 0.2160*100 = 21.60\\3-nitroaniline=\frac{7.81}{25.04} =0.3119*100=31.19[/tex]

2. This experiment has these compounds, benzoic acid (which is an acid), naphthalene (this is neutral) and 3-nitroaniline (this is a base).

to extract, 5 percent of NaOH has to be used in order for benzoic acid to become with sodium hydroxide. the salt would then dissolve in H2O, the other two remaining are going to dissolve in organic layer. and this would make benzoic acid to leave the mix.

we make use of 5 percent of HCl so that the 3-nitroaniline will turn into ammonium salt with the hcl, then the ammonium salt would dissolve in water and naphtalene would become soluble in organic layer. when this happens we would then have the three compounds separated.

Answer:

SN1 substitution reaction

Explanation:

cyclohexanol is a secondary alkanol. The mechanism of acid catalysed dehydration of cyclohexanol involves the protonation of the -OH group.

This is followed by loss of water which is a good leaving group. At this stage, a proton could be abstracted to yield cyclohexene by E1 mechanism or an SN1 substitution reaction may occur to yield Cyclohexyl chloride.

The both reactions are equally likely.

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:

Fill in the blanks with each titration term with its definition.

a. Solution of an unknown concentration that has another solution slowly added to it ________________

b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them ______________

c. A reagent added to the analyte solution that changes color when the reaction is complete ______________

d. Glassware that allows a solution to be precisely and slowly added to another solution _____________

e. Solution of known concentration that is slowly added to a solution of unknown concentration ________________

f. When the required amount of one solution has been added to the second solution to complete the reaction ____________

Explanation:

a. Solution of an unknown concentration that has another solution slowly added to it is called analyte.

b. Process of slowly adding a solution to react with another solution and determine the concentration of one of the solutions based on the reaction between them is called titration.

c. A reagent added to the analyte solution that changes color when the reaction is complete is called an indicator.

d. Glassware that allows a solution to be precisely and slowly added to another solution is called a pipette.

e. Solution of known concentration that is slowly added to a solution of unknown concentration is called titrant.

f. When the required amount of one solution has been added to the second solution to complete the reaction is called neutralization.

Answer:

The general preparation of esters( for example ethyl ethanoate) is through a process known as ESTERIFICATION.

Explanation:

The formation of an ester by the reaction between an alkanol and an acid is known as esterification. This reaction is extremely slow and reversible at room temperature, and is catalyzed by a high concentration of hydrogen ions.

In the preparation of one of the simpler esters known as ETHYL ETHANOATE the reactants include ethanol(an alcohol) and glacial ethanoic acid(a carboxylic acid) in the presence of concentrated tetraoxosulphate VI acid as a CATALYST. Note that, a catalyst is any substance that is able to increase the rate of a chemical reaction.

The mixture is warmed in a water bath( hot but not boiling) for about 25 minutes. The mixture is poured into a beaker partially filled with a sodium or calcium chloride to remove interacted ethanol. The ethyl ETHANOATE floats on the mixture as oily globules.

Answer:

Toluene

Explanation:

This compound is called toluene.

It is a phenyl group where it is bonded a methyl.

It is an aromatic compound.

IUPAC name can be, Methylbenzene.

As an organic compound it can not be dissolved in water.

This can be a reaction of synthesis:

C₆H₅H + CH₃Cl → C₆H₅CH₃ + HCl

Answer:

[tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]

Explanation:

From the question we are told that:

Mass of mixture [tex]m=3.455g[/tex]

Mass of Barium [tex]m_b=0.2815g[/tex]

Equation of Reaction is given as

[tex]Ba2+ + H2SO4 => BaSO4 + 2 H+[/tex]

Generally the equation for Moles of Barium  is mathematically given by

Since

 [tex]Moles of Ba^{2+} = Moles of BaSO_4[/tex]

Therefore

 [tex]Moles of Ba^{2+} = \frac{mass}{molar mass of BaSO4}[/tex]  

 [tex]Moles of Ba^{2+} = \frac{0.2815}{233.39}= 0.0012061 mol[/tex]

Generally the equation for Mass of Barium  is mathematically given by

 [tex]Mass\ of\ Ba^{2+} = Moles * Molar mass of Ba^{2+}[/tex]  

 [tex]Mass\ of\ Ba^{2+} = 0.0012061 * 137.33 = 0.1656 g[/tex]

Therefore

 [tex]Ba\ percentage\ in\ Mass = mass of Ba^{2+}/mass of sample * 100%[/tex]    

 [tex]Ba\ percentage\ in\ Mass= \frac{0.1656}{ 3.455 }* 100%[/tex]

 [tex]Ba\ percentage\ in\ Mass=4.8\%[/tex]