In which orbitals would the valence electrons for selenium (Se) be placed?

Answer:

work out if it's either going to sink or float

Explanation:

this can be carried out by calculating the numbers

Answer:

ABC

Explanation:

hrdjyt

Answer:

Titration is a technique to determine the concentration of an unknown solution. As illustrated in the titration setup above, a solution of known concentration (titrant) is used to determine the concentration of an unknown solution (titrand or analyte).

Typically, the titrant (the solution of known concentration) is added through a burette to a known volume of the analyte (the solution of unknown concentration) until the reaction is complete. Knowing the volume of titrant added allows us to determine the concentration of the unknown analyte. Often, an indicator is used to signal the end of the reaction, the endpoint. Titrant and analyte is a pair of acid and base. Acid-base titrations are monitored by the change of pH as titration progresses.

Let us be clear about some terminologies before we get into the discussion of titration curves.

Answer:

Physical

Explanation:

No new substance is formed.

The process can be reversed using evaporation to separate the sugar from the water

So the change is physical

Hope this helps :)

Answer:

Tollen's test or silver mirror test is use to distinguish between ketone and aldehyde.

Explanation:

Tollen's test is use to distinguish aldehyde from ketone because Tollen reagent consist of silver nitrate and ammonia and it oxidized aldehydes to carboxylic acid and the silver Ag+ is reduced to solid silver Ag. It form a inner film wall on the tube that look like mirror. Ketone do not react with Tollen reagent and therefore does not form silver mirror on the tube wall.

Answer:

From the numerical steps highlighted under explanation, the average atomic mass of bromine is 79.91 u

Explanation:

The steps to be taken will involve;

1) Find the number of isotopes of bromine.

2) Identify the atomic mass and relative abundance of each of the isotopes.

3) Multiply the atomic mass of each of the isotopes by their corresponding values relative abundance value.

4) Add the value in step 3 above to get the average atomic mass of bromine.

Now;

Bromine has 2 isotopes namely;

Isotope 1: Atomic mass = 78.92amu and a relative abundance of 50.69%.

Isotope 2: Atomic mass = 80.92amu and a relative abundance of 49.31%.

Using step 3 above, we have;

(78.92 × 50.69%)

And (80.92 × 49.31%)

Using step 4 above, we have;

(78.92 × 50.69%) + (80.92 × 49.31%) ≈ 79.91 u

The atomic mass of bromine has been calculated as 79.9062 amu.

The relative atomic mass of the element has been given as the mass of each isotope with respect to their abundance.

The atomic mass has been given as:

[tex]amu=\sum mass\;\times\;\% Abundance[/tex]

The available isotopes of Bromine have been:

Isotope 1 = 78.92 amu, and 0.5069 % abundance

Isotope 2= 80.92 amu, and 0.4931 % abundance

Submitting the values for the atomic mass unit of bromine ([tex]amu_{\text{Br}}[/tex]):

[tex]amu_{\text {Br}}= (78.92\;\times\;0.5069)\;+\;(80.92\;\times\;0.4931)\\amu_{\text{Br}}=40.0045\;+\;39.9016\\amu_{\text{Br}}=79.9062[/tex]

The atomic mass of bromine has been calculated as 79.9062 amu.

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Explanation:

The IUPAC system of nomenclature aims to ensure

that every organic compound has a unique, unambiguous name.that the IUPAC name of any compound conveys the structure of that compound to a person familiar with the system.

One way of checking whether the name you have given to an alkane is reasonable is to count the number of carbon atoms implied by the chosen name. For example, if you named a compound 3‑ethyl-4‑methylheptane, you have indicated that the compound contains a total of 10 carbon atoms—seven carbon atoms in the main chain, two carbon atoms in an ethyl group, and one carbon atom in a methyl group. If you were to check the given structure and find 11 carbon atoms, you would know that you had made a mistake. Perhaps the name you should have written was 3‑ethyl-4,4‑dimethylheptane!

Answer:

compound is sp3.

Explanation:

Answer:

32.5

Explanation:

2C⁴H¹⁰ needs 13 O²

5 C⁴H¹⁰ needs (13/2 × 5) O² = 32.5 O²

The answer is D, 32.5

(I took the test)

Answer:

adding a catalyst will increase the reaction rate.

Explanation:

im like 95% sure thats right.

Answer:

A. C. D

Explanation:

ap ex

Answer:

52.8 g of O2.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

4Al + 3O2 —> 2Al2O3

From the balanced equation above,

4 moles of Al reacted with 3 moles of O2 to produce 2 moles of Al2O3

Next, we shall determine the number of mole of O2 needed to react with 2.2 moles of Al. This can be obtained as follow:

From the balanced equation above,

4 moles of Al reacted with 3 moles of O2.

Therefore, 2.2 moles of Al will react with = (2.2 × 3)/4 = 1.65 moles of O2.

Thus, 1.65 moles of O2 is needed for the reaction.

Finally, we shall determine the mass of O2 needed as shown below:

Mole of O2 = 1.65 moles

Molar mass of O2 = 2 × 16= 32 g/mol

Mass of O2 =?

Mole = mass/Molar mass

1.65 = mass of O2 /32

Cross multiply

Mass of O2 = 1.65 × 32

Mass of O2 = 52.8 g

Therefore, 52.8 g of O2 is needed for the reaction.

Answer:

[tex]T_b=239.7K=-33.49\°C[/tex]

Explanation:

Hello!

In this case, since the relationship between entropy and enthalpy for any process is defined below:

[tex]S=\frac{H}{T}[/tex]

For the vaporization of ammonia or any liquid, we can write:

[tex]\Delta S_{vap}=\frac{\Delta H_{vap}}{T_{vap}}[/tex]

In such a way, solving the temperature of vaporization, or boiling point, we have:

[tex]T_{vap}=\frac{\Delta H_{vap}}{\Delta S_{vap}}[/tex]

Plugging in the given enthalpy and entropy of vaporization we obtain:

[tex]T_{vap}=T_b=\frac{23350\frac{J}{mol} }{97.43\frac{J}{mol*K}} \\\\T_b=239.7K=-33.49\°C[/tex]

Best regards!

From the information provided in the question, the boiling point of ammonia is 240 K.

Entropy is the degree of disorderliness in a system. The entropy of a system can be obtained using the relation;

ΔS°vap = ΔH°vap /T

Now;

ΔH°vap = 23.35 kJ/mol

ΔS°vap = 97.43 J/mol·K

T = ?

Making T the subject of the formula and substituting values;

T = ΔH°vap /ΔS°vap

T = 23.35 × 10^3J/mol/97.43 J/mol·K

T = 240 K

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Answer:

carbon-13

Explanation:

Answer:

Explanation:

Answer:

Explanation:  check my paage

Answer:

The answer is letter A.

A. A magnetic field occurs near a wire that has no current.

Because magnetic field occur near a current carrying wire.

Answer:

residue is whatever remains after something else has been removed while filtrate is the liquid or solution that has passed through a filter, and which has been separated from the filtride.

filtration id done by placing a filter paper on the beaker or container then pour the filtride then let it settle and it will pass through and you will have the fitrate and residue

Explanation:

Answer:

The strong forces oppose the electromagnetic force of repulsion between protons. Like ”glue” the strong force keeps the protons together to form the nucleus. The strong forces and electromagnetic forces both hold the atom together.

Explanation:

Hope This helps

Answer:

The strong forces oppose the electromagnetic force of repulsion between protons.

Answer:  The atomic number of oxygen is "O" .

Explanation:

Because Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.

Complete Question

Calculate the pH during the titration of 20.00 mL of 0.1000 M trimethylamine, (CH3)3N(aq), with 0.2000 M HClO4(aq) after 9.48 mL of the acid have been added.Kb of trimethylamine = 6.5 x 10-5.

Answer:

The pH is  [tex]pH = 9.84[/tex]  

Explanation:

From  the question we are told that

   The  volume of trimethylamine, (CH3)3N(aq) is [tex]V_{t} = 20.00mL[/tex]

    The concentration of trimethylamine is [tex]C_t = 0.1000 \ M[/tex]  

    The  volume of HClO4(aq) is [tex]V_{h} = 9.48 mL[/tex]

    The  concentration of  HClO4(aq) is  [tex]C_h = 0.200 M[/tex]

      The Kb  value is  [tex]K_b = 6.5 * 10^{-5}[/tex]

Generally the the pOH of this reaction is mathematically represented as

       [tex]pOH = pK_b + log [\frac{N_h}{N_b} ][/tex]

Here [tex]N_h[/tex] is the number of moles of acid which is evaluated as

      [tex]N_h = C_h * V_h[/tex]

=>    [tex]N_h = 0.200 * 9.48[/tex]

=>    [tex]N_h = 1.896[/tex]

Here [tex]N_t[/tex] is the number of moles of acid which is evaluated as

      [tex]N_t = C_t * V_t[/tex]

=>    [tex]N_t = 0.100 * 20[/tex]

=>    [tex]N_t = 2[/tex]

So

     [tex]pOH = -log(K_b) + log [\frac{N_h}{N_b} ][/tex]

     [tex]pOH = -log(6.5*10^{-5}) + log [\frac{1.896}{2} ][/tex]

=>   [tex]pOH = 4.1639[/tex]

Generally the pH is mathematically represented as

       [tex]pH = 14 - pOH[/tex]

=>    [tex]pH = 14 - 4.1639[/tex]  

=>    [tex]pH = 9.84[/tex]  

Answer: d

Explanation:

On edg

Its called "Ammonium thiocyanate" Have a great day!! <3

Answer:

it is called Ammonium Thiocyanate or Thiourea

Explanation:

it is made made up of 2 nitrogen atoms, 4 hydrogen atoms, 1 sulfur atom and 1 carbon atom. stay safe and have a great day! TPWK

Answer: C

Explanation: Everything else is true.

Answer:

Mass = 185.896 g

Explanation:

Given data:

Mass in gram = ?

Number of moles = 2.00 mol

Solution:

Formula:

Number of moles = mass/molar mass

Molar mass of cobalt (I) hydroxide =92.948 g/mol

by putting the values,

2.00 mol = Mass/92.948 g/mol

Mass = 2.00 mol × 92.948 g/mol

Mass = 185.896 g

Answer:

use google

Explanation:

Answer:

The answer is

Explanation:

The number of molecules present can be found by using the formula

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

From the question we have

N = 4.21 × 6.02 × 10²³

We have the final answer as

Hope this helps you

Answer:

(a) 6332.812 N (b) 1469.59  pounds.

Explanation:

Given that,

The surface area of the top of yu head is 25 cm x 25 cm

Area = 625 cm² = 0.0625 m²

Atmospheric pressure on it is 101325 Pa.

(a) Pressure acting on an object is given by force acting per unit area. It can be written as :

[tex]P=\dfrac{F}{A}\\\\F=PA\\\\F=101325\ Pa\times 0.0625\ m^2\\\\F=6332.812\ N[/tex]

6332.812 N of force is acting on your head at sea level.

(b) If area, A = 100 in²

We know that,

1 atm = 14.6959 pounds/in²

[tex]P=\dfrac{F}{A}\\\\F=PA\\\\F=14.6959 \ \text{Pounds}/in^2\times 100\ in^2\\\\F=1469.59\ \text{pounds}[/tex]

So, the force is 1469.59  pounds.

A. The force required to push your head at sea level is 6332.8125 N

B. The force in pound is 1469.59 lb

A. Determination of the force required at sea level.

Pressure (P) = 101325 Nm²

Area (A) = 25 cm × 25 cm = 0.25 m × 0.25 m = 0.0625 m²

P = F / A

Cross multiply

F = PA

F = 101325 × 0.0625

Therefore, the force required to push your head at sea level is 6332.8125 N

B. Determination of the force in pounds

Area (A) = 100 in²

Pressure (P) = 14.6959 pound / in²

F = PA

F = 14.6959 × 100

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