Which elements are main-group elements?
1. Te
2. K
3. V
4. Re
5. Ag

Answers

Answer 1

Answer:

Te

K

Explanation:

Main group elements are elements designated and located on the s-block and p-block on the periodic table. The core group or prominent elements are the elements that make up those groups. These groupings comprise the most naturally rich and abundant elements. The main group elements are those whose characteristics are more predicted as a function of their periodic table location. From the given options, only Te and K are elements of the main-group.


Related Questions

Who knows Cameron Herrin?​

Answers

Explanation:

Cameron Herrin has killed a mother and her baby on a highway in Tampa, Florida

on 2018 on a illegal race


A scientific hypothesis is
ANSWER:
predictive.
testable.
explanatory.
all of the above.

Answers

Answer:

All of the above.

Explanation:

For a scientific hypothesis to be considered a hypothesis, it has to be testable. When conducting a lab experiment, it also allows the tester to predict what might occur during and after the experimentation. They are also explanatory. For example, theories are hypotheses that have been verified and can explain why something in nature takes place.

Consider the following equilibrium:
2H2(g)+S2(g)⇌2H2S(g)Kc=1.08×107 at 700 ∘C.

What is Kp?

Answers

Answer:

Consider the following equilibrium:

2H2(g)+S2(g)⇌2H2S(g)Kc=1.08×107 at 700 ∘C.

What is Kp?

Explanation:

Given,

[tex]Kc=1.08 * 10^7[/tex]

The relation between Kp and Kc is:

[tex]Kp=Kc * (RT)^d^e^l^t^a^(^n^)[/tex]

Where delta n represents the change in the number of moles.

For the given equation,

The Delta n = Number of moles of products - number of moles of reactants

(2-(2+1))

=-1.

Hence,

Kp=Kc/RT.

Thus,

[tex]Kp=1.08 * 10^7 / 8.314 J.K6-1.mol^-^1 x 973 K\\Kp=1335.06[/tex]

The answer is Kp=1335.06

The value of [tex]K_p[/tex] is [tex]1.35\times 10^5[/tex].

Explanation:

The relation between [tex]K_p \& K_c[/tex] is given by:

[tex]K_p=K_c(RT)^{\Delta n_g}[/tex]

Where:

[tex]K_c[/tex] = The equilibrium constant of reaction in terms of concentration

[tex]K_p[/tex] = The equilibrium constant of reaction in terms of partial pressure

R= The universal gas constant

T = The temperature of the equilibrium

[tex]n_g[/tex]= Change in gaseus moles

Given:

An equilibrium reaction, 700°C:

[tex]2H_2(g)+S_2(g)\rightleftharpoons 2H_2S(g),K_c=1.08\times 10^7[/tex]

To find:

The equilibrium constant in terms of partial pressure, [tex]K_p[/tex].

Solution:

The equilibrium constant of reaction in terms of concentration= [tex]K_c[/tex]

[tex]K_c=1.08\times 10^7[/tex]

The equilibrium constant of reaction in terms of partial pressure =[tex]K_p=?[/tex]

The gaseous moles of reactant side = [tex]n_r= 3[/tex]

The gaseous moles of product side = [tex]n_p= 2[/tex]

The temperature at which equilibrium is given = T

[tex]T = 700^oC+273.15 K=973.15K[/tex]

The change in gaseous mole  = [tex]n_g=n_p-n_r=2-3 = -1[/tex]

[tex]K_p=1.08\times 10^7\times (0.0821 atm L/mol K\times 973.15 K)^{-1}\\K_p=1.35\times 10^5[/tex]

The value of [tex]K_p[/tex] is [tex]1.35\times 10^5[/tex].

Learn more equilibrium constants here:

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Give your familiarity for following terms

1. roasting 2. smelting 4. zone refining 5. polling​

Answers

Answer:

The roasting process is a delicate combination of art and science . Roasters are familiar with how the beans look and the smells Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests .Well, familiarity with the machine makes things much easier to predict, but the best way is to do many different tests.Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals.In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining. In zone refining, solutes are segregated at one end of the ingot in order to purify the remainder, or to concentrate the impurities. ... For example, in the preparation of a transistor or diode semiconductor, an ingot of germanium is first purified by zone refining.Polling is the process where the computer or controlling device waits for an external device to check for its readiness or state, often with low-level hardware. For example, when a printer is connected via a parallel port, the computer waits until the printer has received the next character.

Explanation:

hope it heloed

In what kind of orbital do the lone-pair electrons on the nitrogen of dimethylacetamide reside, and is it in the same plane as the ch3 groups

Answers

Answer:

The lone pairs on nitrogen in dimethylacetamide reside in sp3 orbitals which are coplanar with the methyl groups

Explanation:

The compound dimethylacetamide consists of oxygen bearing two lone pairs of electrons and a nitrogen atom bearing a lone pair of electrons and has two methyl groups attached to the nitrogen atom.

The lone pair on the nitrogen atom is accommodated in an sp3 orbital of nitrogen as shown in the question. This sp3 orbital is coplanar with the two methyl groups.

Evaporation is commonly used to concentrate dissolved solids in a liquid feed stream and produce pure water vapor.

a. True
b. False

Answers

Answer:

True

Explanation:

Evaporation is the process by which a substance changes its state from liquid to gas. evaporation occurs at all temperatures but it's rate increases as temperature increases.

Pure water vapour can be produced by evaporation.

As the liquids are removed, the solids present in solution becomes more concentrated.

what is the machine used to check melting point called?​

Answers

Answer:

Melting-point apparatus

Liquid octane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Suppose 10.3 g of octane is mixed with 23. g of oxygen. Calculate the maximum mass of water that could be produced by the chemical reaction. Round your answer to significant digits.

Answers

Answer:

9.36 g

Explanation:

The equation of the reaction is;

C8H18(g) + 25/2 O2(g) ----> 8CO2(g) + 9H2O(g)

Number of moles of octane = 10.3g/ 114 g/mol = 0.09 moles

1 mole of octane yields 9 moles of water

0.09 moles of octane yields 0.09 × 9/1 = 0.81 moles of water

Number of moles of oxygen = 23g/32g/mol = 0.72 moles

12.5 moles of oxygen yields 9 moles of water

0.72 moles of oxygen yields 0.72 × 9/12.5 = 0.52 moles of water

Hence oxygen is the limiting reactant;

Maximum mass of water produced = 0.52 moles of water × 18 g/mol = 9.36 g

when a polar bond is formed between 2 atoms which atom receives a partial positive charge

Answers

Answer:

The more electronegative atom in a covalent bond

the pressure of a sample of gas at constant volume is 942 kPa at 338K. what will the pressure be 293k?

Answers

Explanation:

4 tctcgcgcgctctchvvyctctc

How many liters of hydrogen can be produced at a pressure of 2 atm and a temperature of 298 K

Answers

Answer:

1.17 L of H₂

Explanation:

We'll begin by calculating the number of mole in 2.3 g of Mg. This can be obtained as follow:

Mass of Mg = 2.3 g

Molar mass of Mg = 24 g/mol

Mole of Mg =?

Mole = mass /molar mass

Mole of Mg = 2.3 / 24

Mole of Mg = 0.096 mole

Next, we shall determine the number of mole of H₂ produced by the reaction of 2.3 g (i.e 0.096 mole) of Mg. This can be obtained as follow:

Mg + 2HCl —> MgCl₂ + H₂

From the balanced equation above,

1 mole of Mg reacted to 1 mole of H₂.

Therefore, 0.096 mole of Mg will also react to produce 0.096 mole of H₂.

Finally, we shall determine volume of H₂ produced from the reaction. This can be obtained as follow:

Number of mole (n) of H₂ = 0.096 mole

Pressure (P) = 2 atm

Temperature (T) = 298 K

Gas constant (R) = 0.0821 atm.L/Kmol

Volume (V) of H₂ =?

PV = nRT

2 × V = 0.096 × 0.0821 × 298

Divide both side by 2

V = (0.096 × 0.0821 × 298) /2

V = 1.17 L

Therefore, 1.17 L of H₂ were obtained from the reaction.

Calculate the osmotic pressure of 5.0g of sucrose ssolution in 1L. Answer should be in Torr

Answers

Answer: The osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.

Explanation:

Given: Mass = 5.0 g

Volume = 1 L

Molar mass of sucrose = 342.3 g/mol

Moles are the mass of a substance divided by its molar mass. So, moles of sucrose are calculated as follows.

[tex]Moles = \frac{mass}{molarmass}\\= \frac{5.0 g}{342.3 g/mol}\\= 0.0146 mol[/tex]

Hence, concentration of sucrose is calculated as follows.

[tex]Concentration = \frac{moles}{Volume (in L)}\\= \frac{0.0146 mol}{1 L}\\= 0.0146 M[/tex]

Formula used to calculate osmotic pressure is as follows.

[tex]\pi = CRT[/tex]

where,

[tex]\pi[/tex] = osmotic pressure

C = concentration

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the values into above formula as follows.

[tex]\pi = CRT\\= 0.0146 \times 0.0821 L atm/mol K \times 298 K\\= 0.357 atm (1 atm = 760 torr)\\= 271.32 torr[/tex]

Thus, we can conclude that the osmotic pressure of 5.0g of sucrose solution in 1 L is 271.32 torr.

a. Draw 2,3-dichloro octane.
b. Write the lewis structure for H20 molecule.

Answers

Answer:

a.draw 2,3 dicholoro octane

Explanation:

mag isip ka kung paano hehe

If you ran the reaction for this experiment and began with 65.0 mmol of isopentyl alcohol, how many grams of isopentyl acetate could you theoretically produce assuming only a 77.0% attainable yield

Answers

Answer:

6.52g = Actual yield (g)

Explanation:

The yield of a reaction is:

Percent yield = Actual yield (g) / Theoretical Yield (g) * 100

As 1 mol of isopentyl alcohol produce 1 mol of isopentyl acetate (Theoretical Yield), the theroretical yield of isopentyl acetate is 65.0mmol = 0.0650mol. To solve this question we need to convert the moles of isopentyl acetate to mass using its molar mass (130.19g/mol).

With the equation of percent yield we can find the mass obtained as follows:

Theoretical yield:

0.0650mol * (130.19g/mol) = 8.46g of isopentyl alcohol

Mass produced:

77 = Actual yield (g) / 8.462g * 100

6.52g = Actual yield (g)

The mass of isopentyl acetate that can be produced is 6.52 g

Balanced equation

See attached photo

From the balanced equation,

1 mole of isopentyl alcohol reacted to produce 1 mole of isopentyl acetate.

Therefore,

65 mmole (i.e 0.065 mole) of isopentyl alcohol will also react to produce 0.065 mole of isopentyl acetate.

How to determine the actual yield (in mole) Percentage yield = 77%Theoretical yield = 0.065 mole Actual yield =?

Actual yield = percent × theoretical

Actual yield = 77% × 0.065

Actual yield = 0.05005 mole

How to determine the mass Mole of isopentyl acetate = 0.05005 mole Molar mass of isopentyl acetate = 130.19 g/molMass of isopentyl acetate =?

Mass = mole × molar mass

Mass of isopentyl acetate = 0.05005 × 130.19

Mass of isopentyl acetate = 6.52 g

Learn more about stoichiometry:

https://brainly.com/question/14735801

Please can someone please help me !!

Answers

Answer:

False

Explanation:

Consider the balanced chemical equation below.

3 A ⟶ C + 4 D

How many moles of C would be produced if 7 moles of A were used?

Answers

Answer:

2.33 mol C

Explanation:

Step 1: Write the balanced generic chemical equation

3 A ⟶ C + 4 D

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of A to C is 3:1.

Step 3: Calculate the number of moles of C produced from 7 moles of A

We will use the previously established molar ratio.

7 mol A × 1 mol C/3 mol A = 2.33 mol C

Cis-4-tertButylcyclohexyl bromide (compound 1) and Trans-4 tert Butylcyclohexylbromide (compound 2) are reacted with Potassium Tertiary butoxide in Tertiary butanol to produce 4-tertbutylcyclohexene. The following statement is completely true?A. In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the axial position and in compound 2 both the Tert butyl and the bromine occupy equatorial positions. Compound 1 reacts faster than compound 2.
B. In compound 1 the Tert butyl group occupies the axial position and the Bromine occupies the axial position and in compound 2 both the Tert butyl and the bromine occupy equatorial positions. Compound 1 reacts faster than compound 2.
C. In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the equatorial position and in compound 2 both the Tert butyl and the bromine occupy equatorial positions. Compound 1 reacts faster than compound 2.
D. 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.
E. In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the axial position and in compound 2 both the Tert butyl occupies the equatorial and the bromine occupies axial position. Compound 1 reacts faster than compound 2.
F. In compound 1 the Tert butyl group occupies the equatorial position and the Bromine occupies the axial position and in compound 2 both the Tert butyl and the bromine occupy equatorial positions. Compond 2 reacts faster than compound 1.

Answers

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.

Indicate type of chemical reactions for 2Mgl2+MN(SO3)2=2MgSO3+Mnl4

Answers

Answer:

double decomposition reaction

Which term can be used to describe the process in the reaction below? 2 NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g)

Answers

Answer:

Decomposition

Explanation:

If we look at the process;

2 NaHCO3 (s) → Na2CO3 (s) + H2O (g) + CO2 (g)

We can see that NaHCO3 was broken down into Na2CO3, H2O and CO2.

The breakdown of one compound to yield other chemical compounds is known as decomposition.

Hence the NaHCO3 was decomposed in the process above.

What is the percent yield of the reaction below if 84.0 grams of Al2O3(s) is recovered from a reaction whose theoretical yield of Al2O3(s) is 104 grams?
4 Al(s) + 3 O2(g) → 2 Al2O3(s)

Answers

Answer:

80.8%

Explanation:

Let's consider the following balanced equation.

4 Al(s) + 3 O₂(g) → 2 Al₂O₃(s)

The mass obtained of Al₂O₃ (experimental yield) is 84.0 g. The theoretical yield of Al₂O₃ is 104 g. We can calculate the percent yield of Al₂O₃ using the following expression.

%yield = (experimental yield / theoretical yield) × 100%

%yield = (84.0 g / 104 g) × 100% = 80.8%

Answer:

Percent Yield = 80.8%

Explanation:

We can find the percent yield of a reaction using the equation:

Percent yield = Actual yield (g) / Theoretical Yield (g) * 100

Where Actual yield is the amount of product produced (84.0g)

And theoretical yield is the mass produced assuming a 100% of product (104.0g)

Replacing the computed values:

Percent yield = 84.0g / 104.0g * 100

Percent Yield = 80.8%

Balance the chemical equation below using the smallest possible whole number stoichiometric coefficients.
P4(s) + NaOH(aq) + H2O(l) -> Ph3(g) + Na2HPO3(aq)

Answers

Answer:

I used a,b c, d in the equation as substituted coefficients to find the unknown for each element of P, Na, O, H, and I got

P4(s) + 4NaOH(aq) + 2H20(l)---->2Ph3 +2Na2HPO3(aq).

which I think should be the answer.

Ammonia is produced by the reaction of nitrogen and hydrogen: N2(g) + H2(g)  NH3(g)
(a) Balance the chemical equation.
(b) Calculate the mass of ammonia produced when 35.0g of nitrogen reacts with hydrogen.

Answers

Answer:

a) N2 (g) + H2 = 2 NH3

b) You have to state the mass of hydrogen

Compound X has a molar mass of 316.25 g*mol^-1 and the following composition:
element & mass %
phosphorus & 39.18%
sulfur & 60.82%
Write the molecular formula of X.

Answers

Answer:

Compound X has a molar mass of 316.25 g*mol^-1 and the following composition:

element & mass %

phosphorus & 39.18%

sulfur & 60.82%

Write the molecular formula of X.

Explanation:

The given molecule of phosphorus and sulfur has molar mass --- 316.25 g.

Empirical formula calculation:                      

element:              phosphorus                       sulfur

co9mposition:      39.185%                            60.82%

divide with

atomic mass:          39.185/31.0 g/mol           60.82/32.0g/mol

                              =1.26mol                           1.90mol

smallest mole ratio:   1.26mol/1.26mol =1      1.90mol/1.26 mol =1.50

multiply with 2:          2                                         3

Hence, the empirical formula is:

P2S3.

Mass of empirical formula is:

158.0g/mol

Given, molecule has molar mass --- 316.25 g/mol

Hence, the ratio is:

316.25g/mol/158.0 =2

Hence, the molecular formula of the compound is :

2 x (P2S3)

=[tex]P_4S_6[/tex]

Which equation obeys the law of conservation of
mass?

Answers

Answer:2C4H10+2C12+12O2 4CO2+CC14+H20

What molecule is this

Answers

Answer:

That is a " ball and stick " model which represents carbon compounds.

Explanation:

This is the answer. Hope it helps you find what you're looking for.

g A piece of solid Zn metal is put into an aqueous solution of Cu(NO3)2. Write the net ionic equation for any single-replacement redox reaction. (Use the lowest possible coefficients for the reaction. Be sure to specify states such as (aq) or (s). If a box is not needed, leave it blank. If no reaction occurs, leave all boxes blank and click on Submit.)

Answers

Answer:

Zn(s) + Cu²⁺(aq) ⇒ Zn²⁺(aq) + Cu(s)

Explanation:

Let's consider the molecular single displacement equation between Zn and Cu(NO₃)₂

Zn(s) + Cu(NO₃)₂(aq) ⇒ Zn(NO₃)₂(aq) + Cu(s)

The complete ionic equation includes all the ions and insoluble species.

Zn(s) + Cu²⁺(aq) + 2 NO₃⁻(aq) ⇒ Zn²⁺(aq) + 2 NO₃⁻(aq) + Cu(s)

The net ionic equation includes only the ions that participate in the reaction and insoluble species.

Zn(s) + Cu²⁺(aq) ⇒ Zn²⁺(aq) + Cu(s)

Consider an acid-base titration in which the base is dispensed from a burette into a flask containing an acid. If any drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be

Answers

Answer:

Higher than the actual value

Explanation:

Titration is a volumetric process in which a known volume of solution is dispensed from a burette to react with a known volume of solution in a conical flask.

When acid-base titration is carried out in such a way that the base is in the burette and the acid is in the conical flask and drops of the base adhere to the inner walls of the flask, but do not actually mix with the solution, the calculated acid concentration would be higher than the actual value.

This is because;

From CA= CBVBnA/VAnB

When VB(volume of base) that reacted is lower than the actual volume recorded, then the calculated volume of CA(concentration of acid) is much higher than the actual value since drops of the base adhere to the inner walls of the flask.

Methanoic acid is the simplest carboxylic acid molecule. It has one carbon atom. Draw the structural model for methanoic acid (using C and H).

Answers

ANSWER IS ABOVE

THE METHANOIC ACID

can anybody pls help me with chemistry how to balance an equation of class 7 ??? pls
really I don't like chemistry..
I need only the step(s)..

Answers

Answer:

[tex] This\:may\: help[/tex]

Answer:

(1) Write down the chemical reaction in the form of word equation,keeping reactants on left hand side and products on right hand side.

(2) Write symbol and formula of all reactants and products in word equation. (3) Balance the equation by multiplying the symbols and formula by smallest possible figures.

The chemical formula is different from the empirical formula in

Answers

Answer:be careful and relax

Explanation:

Answer:

Hahaha be careful and relax

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