How many Noble gases we have in Periodic Table???

Answers

Answer 1

Answer:

Six

Explanation:

Answer 2
6.

The six naturally occurring noble gases are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and the radioactive radon (Rn).

Related Questions

convert 8.4 • 10^16 molecules of CO2 to moles

Answers

Answer:

0.00000000000000084

Explanation:

Convert 1.16 mol of calcium cyanide, Ca(CN)2, to mass.

Answers

here it the answers in pencil

Which combination of reagents used in the indicated order with benzene will give m-nitropropylbenzene? a. 1) CH3CH2CH2Cl/AlCl3, 2) HNO3/H2SO4 b. 1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3 c. 1) CH3CH2CH2Cl/AlCl3, 2) HNO3/H2SO4, 3) Zn/HCl d. 1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3, 3) Zn/HCl

Answers

Answer:

1) HNO3/H2SO4, 2) CH3CH2CH2Cl/AlCl3

Explanation:

Benzene is a stable aromatic compound hence it undergoes substitution rather than addition reaction.

When benzene undergoes substitution reaction, the substituent introduced into the ring determines the position of the incoming electrophile.

If I want to synthesize m-nitropropylbenzene, I will first carry out the nitration of benzene using HNO3/H2SO4 since the -nitro group is a meta director. This is now followed by Friedel Craft's alkykation using CH3CH2CH2Cl/AlCl3.

increasing temperature increases:
1:Enthalpy
2:Free Energy
3:Entropy
4:Specific heat​

Answers

Answer:

2 :free energy

Explanation:

I hope it is fine answer for you ☺️☺️☺️

How many oxygen atoms are there in 0.25 mole of CO2?

Answers

Answer:

It is known that 1 mol of a molecule contains 6.023×1023 6.023 × 10 23 number of molecules. So, 0.25 moles of CO2 C O 2.

The correct option for the given question about Mole Concept is Na / 2 atom of oxygen.

What is mole?In chemistry, a mole is a unit. A mole of a substance is the mass of the substance containing precisely 12 gram of the same number of atoms as 12C.The mole is the SI unit used to measure a substance's quantity. It has the symbol mol.

How to solve this question?

In 1 mole number of molecules of CO₂ = Na (Avagadro Number)

In 0.25 mole number of molecules of CO₂ = 0.25 × Na molecules

In 1 molecule number of oxygen atom = 2 atom

In 0.25 × Na molecules number of oxygen atom = 2 × 0.25 × Na atom

In 0.25 × Na molecules number of oxygen atom = 0.5 × Na atom

So in 0.25 mole of CO₂ number of oxygen atom = Na / 2 atom

Thus we can conclude that in 0.25 mole of CO₂ number of oxygen atom will be Na / 2, where Na is Avagadro Number.

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Ammonium phosphate NH43PO4 is an important ingredient in many fertilizers. It can be made by reacting phosphoric acid H3PO4 with ammonia NH3. What mass of ammonium phosphate is produced by the reaction of 5.5g of phosphoric acid

Answers

Answer:

8.3 g

Explanation:

Step 1: Write the balanced equation

H₃PO₄ + 3 NH₃ ⇒ (NH₄)₃PO₄

Step 2: Calculate the moles corresponding to 5.5 g of H₃PO₄

The molar mass of H₃PO₄ is 97.99 g/mol.

5.5 g × 1 mol/97.99 g = 0.056 mol

Step 3: Calculate the moles of (NH₄)₃PO₄ produced

The molar ratio of H₃PO₄ to (NH₄)₃PO₄is 1:1. The moles of (NH₄)₃PO₄ produced are 1/1 × 0.056 mol = 0.056 mol.

Step 4: Calculate the mass corresponding to 0.056 moles of (NH₄)₃PO₄

The molar mass of (NH₄)₃PO₄ is 149.09 g/mol.

0.056 mol × 149.09 g/mol = 8.3 g

When comparing Be2 and H2:

I. Be2 is more stable because it contains both bonding and antibonding valence electrons.
II. H2 has a higher bond order than Be2.
III. H2 is more stable because it only contains 1s electrons.
IV. H2 is more stable because it is diamagnetic, whereas Be2 is paramagnetic

a. II,III,IV
b.II,III
c.III only
d.I,II
e.III,IV.

Answers

Answer:

The answer is "Option b".

Explanation:

H2 does have bond energy of 1, while Be2 has a covalent bond of zero. Be2 has eight electrons, each of which dwells in a distinct orbital. As just a result, four of them are linked molecular orbitals and two are antibonding molecular orbitals, respectively. As just a result, this molecule is unstable. This chemical orbital, with a bond order of 1, has just two electrons. As a result, it is a very solid substance. H2's bond length is higher than Be2's. Since it only has one electron, H2 is more stable than that of other compounds.

An hibernating bear accumulates 25 kg of a triglyceride (846 g/mol) comprising the following fatty acids: C16, C17 and C18∆9. How many grams of β-hydroxybutyrate (104 g/mol) can the bear produce from this triglyceride during its hibernation?

Answers

The quantity of β-hydroxybutyrate the bear can produce

during hibernation is 3,073.30grams.

Hibernation is defined as the period of less activity by animals to conserve energy to survive coarse weather conditions.

A typical example of an animal that hibernates is the bear.

From the question, a bear is able to accumulate 25kg (25000grams) of triglyceride.

To calculate quantity of β-hydroxybutyrate that would be produced from 25kg triglyceride;

846g of triglyceride = 104grams of β-hydroxybutyrate

25000g of triglyceride = x grams

(Cross multiple to solve for x grams)

X = 104 × 25000/846

[tex]x = \frac{104 \times 25000}{846} [/tex]

[tex]x = \frac{2600000}{846} [/tex]

[tex]x = 3073.30grams[/tex]

Therefore, the quantity of β-hydroxybutyrate the bear can produce during hibernation is 3,073.30grams.

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How can a redox reaction be identified?
O A. Atoms have rearranged.
O B. Protons have been transferred.
.
O
C. lons are present in solution.
D. Oxidation states have changed.

Answers

Answer:

'Oxidation states have changed.'

Explanation:

Redox Reactions can be identifiable by a change in oxidation number/states of two of the atoms in the reaction. Any reaction in which no oxidation numbers/state change is not a redox reaction.

Element X has an electron configuration of 2-8-2. This element will combine with the oxide ion to form a compound with the formula

Answers

2+8+2 = 12 electrons
Magnesium has 12 electrons
Magnesium and oxide combine to for Magnesium Oxide
Mg^2+ + O^2- = MgO

In order to complete the reaction of hexyl magnesium bromide with acetone, what next step needs to be done.
a. Fractional Distillation.
b. Vacuum filtration.
c. Aqueous workup.
d. Crystallization.

Answers

Answer:

Aqueous workup.

Explanation:

The reaction of hexyl magnesium bromide with acetone yields a tertiary alcohol. There is an organic phase and an aqueous phase.

Aqueous workup is the process of recovering the pure tertiary alcohol from the organic phase of the system.

Hence, in order to complete the reaction of hexyl magnesium bromide with acetone, aqueous workup is required.

An ordinary gasoline can measuring 30.0 cm by 20.0 cm by 15.0 cm is evacuated with a vacuum pump.
1a. Assuming that virtually all of the air can be removed from inside the can, and that atmospheric pressure is 14.7 psi, what is the total force (in pounds) on the surface of the can?
1b. Do you think that the can could withstand the force?

Answers

Answer:

Explanation:

From the given information:

The surface area of the can = (30 × 20 × 2) +(20× 15 × 2) +(30 × 15 × 2)

= 1200 + 600 + 900

= 2700 cm²

Since 1 inch² = 0.155 inch²

The surface area in inches² = 2700 × 0.155 inch²

= 418.5 inches²

The total force can be determined by using the expression:

Force = Pressure ×Area

Force = 14.7 psi ×  418.5 inches²

Force = 6151.95 lbs

Yes, the gasoline can will be able to withstand the force.

Define atomic numbers and mass numbers

Answers

Atomic numbers is the number of a chemical element in the periodic table and the mass number is the total number of protons and neutrons in an atom

Answer:

1). Atoms of each element contain a characteristic number of protons. In fact, the number of protons determines what atom we are looking at (e.g., all atoms with six protons are carbon atoms); the number of protons in an atom is called the atomic number.

2) In contrast, the number of neutrons for a given element can vary. Forms of the same atom that differ only in their number of neutrons are called isotopes.

3) Together, the number of protons and the number of neutrons determine an element’s mass number: mass number = protons + neutrons. If you want to calculate how many neutrons an atom has, you can simply subtract the number of protons, or atomic number, from the mass number.

An analytical chemist is titrating of a solution of benzoic acid with a solution of . The of benzoic acid is . Calculate the pH of the acid solution after the chemist has added of the solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of solution added.

Answers

The question is incomplete. The complete question is :

An analytical chemist is titrating 148.9 mL of a 1.100 M solution of benzoic acid [tex]$HC_6H_5CO_2$[/tex]  with a 0.3600 M solution of KOH. The [tex]pK_a[/tex]  of benzoic acid is 4.20. Calculate the pH of the acid solution after the chemist has added 232.0 mL of the KOH solution to it. Note for advanced students: you may assume the final volume equals the initial volume of the solution plus the volume of KOH solution added.

Solution :

Number of moles of [tex]$C_6H_5OCOOH$[/tex] [tex]$=148.9 \ mL \times \frac{L}{1000\ mL} \times \frac{1.100 \ mol}{L}$[/tex]

                                                         = 0.16379 mol

Number of moles of NaOH added [tex]$=232.0 \ mL \times \frac{L}{1000\ mL} \times \frac{0.3600 \ mol}{L}$[/tex]

                                                         = 0.08352 mol

ICE table :

                     [tex]C_6H_5OCOOH \ \ \ + \ \ \ OH^- \ \ \ \rightarrow \ \ C_6H_5OCOO^- \ \ \ \ + \ \ H_2O[/tex]

I (mol)              0.16379                 0.08352              0

C (mol)           -0.08352              -0.08352            +0.08352

E (mol)            0.08027                    0                    0.08352

Total volume = (148.9 + 232) mL

                      = 380.9 mL

                     = 0.3809 L

Concentration of [tex]$C_6H_5OCOOH, [C_6H_5OCOOH]$[/tex] [tex]$=\frac{0.08027 \ mol}{0.3809 \ L}$[/tex]

                                                                               = 0.211 M

Concentration of [tex]$C_6H_5OCOO^- , [C_6H_5OCOO^-] =\frac{0.08352 \ mol}{0.3809 \ L}[/tex]

                                                                              = 0.219 M

[tex]pK_a[/tex] of [tex]C_6H_5OCOOH = 4.20[/tex]

According to Henderson equation,

[tex]$pH = pK_a + \log \frac{[C_6H_5OCOO^-]}{[C_6H_5OCOOH]}[/tex]

     [tex]$=4.20 + \log \frac{0.219}{0.211}$[/tex]

     = 4.22

Therefore, the pH of the acid solution is 4.22

What is the molarity of a solution that contains 0.75 mol Naci in 3.0 L of solution? Select one: O a. 4.0 M O b. 2.3 M O d. 3.8 M O d. 0.25 M Clear my choice​

Answers

Answer:

[tex]\boxed {\boxed {\sf D. \ 0.25 \ M}}[/tex]

Explanation:

Molarity is a measure of concentration in moles per liter.

[tex]molarity= \frac{moles \ of \ solute}{ liters \ of \ solution}[/tex]

The solution contains 0.75 moles of sodium chloride and has a volume of 3.0 liters.

moles of solute = 0.75 mol NaCl liters of solution = 3.0 L

Substitute these values into the formula.

[tex]molarity= \frac{ 0.75 \ mol \ NaCl}{3.0 \ L}[/tex]

[tex]molarity= 0.25 \ mol \ NaCl/L[/tex]

Molarity has the molar (M) as its unit. 1 molar is equal to 1 mole per liter.

[tex]molarity= 0.25 \ M \[/tex]

The molarity of the solution is 0.25 Molar and Choice D is correct.

If we increase the temperature of the reaction that occurs in plants to create sugar. What direction does the equilibrium shift....

- Products
- No change
- Reactants
- Plants are not capable of this

Answers

The reaction used to produce sugar in plants is Photosynthesis,

6CO₂ + 6H₂O + heat ⇆ C₆H₁₂O₆ + 6O₂↑

we can see that this reaction is endothermic, it absorbs heat to occur

If we were to add more heat or increase the temperature, the left side of the equilibrium will be able to react much more, which would produce more glucose (aka sugar)

Hence increasing the temperature will shift the equilibrium to the right or towards the Products

Answer:

Explanation:

The reaction that occurs in plants to create sugar can be represented by the following equation:

6 CO2 + 6 H2O ↔ C6H12O6 + 6 O2

It is called photosynthesis because the reaction requires light energy for the plant.  The reaction is controlled by enzyme within the plant. An increase in temperature will increase the collisions between enzyme and reactants; shifting the equilibrium towards the products, sugar and oxygen.

What is the empirical formula for a compound that is comprised of 54.0% sodium, 8.50% boron, and 37.5% oxygen by mass

Answers

Answer:  

Sodium metaborate: sodium+boron+oxygen= NaBO 2.

The formula can be written also as Na 2O·B

Explanation:

4) Calculate the percentage by
mass of oxygen in Pb(NO3)2
A) 193
B20
145

Answers

Answer:

  im getting 331.23

Explanation:

Element Number Mass Percet Composition

O            6         16.00  28.9828819853274

N             2         14.01 8.45937867946744

Pb             1        207.21 62.5577393352051

what is wrong with the statement? "because there are no common factors in the molecular formula, k2co3 is also the empirical formula of potassium carbonate"

Answers

The empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound.

The empirical formula of a compound shows the ratio of atoms of each element in the compound while the molecular formula shows the number of atoms of each element in the compound.

For the compound, K2CO3, the empirical formula is the same as the molecular formula because the ratio of atoms in the compound correspond to the number of atoms of each element in the compound. It has nothing to do with common factors.

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Which of the following is a reduction half-reaction?

Answers

Solution : An oxidation reduction (redox) reaction is a type of chemical reaction that involves a transfer of electrons between tow species an oxidaion reductin reaction is any chemical reaction in which the oxidation number of a molecule atom or ion changes by gaining or losing an electron

Choose the compound below that contains at least one polar covalent bond, but is nonpolar.
a. SiF4
b. SeF4
c. HCl
d. ICl3
e. Both SiF4 and ICl3 are nonpolar and contain a polar covalent bond.

Answers

Answer:

HCl contain a polar covalent bond because H is more electropositive than Cl and Cl is more electronegative than H, resulting in a dipole moment

Which condition is usually associated with low air pressure systems?

Answers

Answer:

clouds and precipitation that minimize temperature changes throughout the day

Explanation:

26. Which group in the periodic table contains
an element that can form a blue sulfate
a
compound?
(1) 1
(2)
(3) 11
(4) 17

Answers

Answer:

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Answer:

Option (3) 11

Explanation:

Elements in Group 11 of the periodic table are called Noble Metals.Noble metals have high resistance to oxidation and low chemical reactivity.Noble metal includes Gold (Au), Silver (Ag), Copper (Cu).Copper forms a blue sulfate when reacts with Sulphuric Acid.Formula of Copper Sulfate : CuSO4.Since, Copper belongs to the Group 11 elements of the periodic table hence, option (3) is the right answer.

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3 molecules NaOH determine the amount of grams

Answers

Answer:

In three mocelus 0.0001 gram.

Please write out the balanced chemical equations for the following
reactions.
**Ensure you write the states of the reactants and products.**
• zirconium chloride reacts with scandium dichromate

Answers

Answer: Super idol

Explanation:

chinese malapoks

LAST ATTEMPT! Covalent compound naming ! !!

Answers

Answer:

Name the non-metal furthest to the left on the periodic table by its elemental name.

Name the other non-metal by its elemental name and an -ide ending.

Use the prefixes mono-, di-, tri-.... to indicate the number of that element in the molecule.

im prolly wrong

30 points!!!!

2K + 2H2O → 2KOH + H2

This reaction shows which detail about potassium and hydrogen?
Hydrogen is more reactive than potassium.
Potassium and hydrogen form ionic bonds.
Potassium is more reactive than hydrogen.
Potassium and hydrogen form covalent bonds

Answers

Answer:

2K + 2H2O → 2KOH + H2

So Hydrogen is more reactive than pottasium .

According to law of conservation of matter, 2 moles of potassium react with water to produce 1 mole of hydrogen gas.

So, 2 moles of potassium produce 1 mole of hydrogen gas.

Answer:

A

Explanation:

Hydrogen is more reactive than potassium.

Assume you have 4 solids (A, B, C and D) of similar mass. Which of these requires the greatest energy input to melt?


polar covalent

covalent network

ionic compound

nonpolar covalent

Answers

The solid that require the greatest energy input to melt by mass is the option;

Covalent network

Reason for the above answer is as follows;

The elementary particles of a solid are held together by bonds that require

an input of energy to unlock, and once broken, the particles are then able

to change location within their containing vessels with less restrictions

Types of bonds

Polar covalent molecular solids have the following characteristics;

a) Soluble in water b) Low melting point, b) Conduct electricity

Solids that are made up of a covalent network have the following characteristics

a) High melting point temperature b) Non conductive of electricity c) Not soluble in water

Solids of ionic compounds have the following characteristics;

a) High melting point temperature b) The liquid state and solution

conducts electricity c) Soluble in water

Solids that have nonpolar covalent bonds have;

a) Low melting point b) Normally in the gaseous or liquid state b) Not water soluble

Therefore, the covalent network, and the solids ionic compounds require the most energy to melt, however, the strength of the ionic bond in an ionic compound is a factor the charges present and the sizes of the atom, while

the covalent network solid, are combined to form essentially as a single

molecule and therefore require the greatest heat energy input break the bonds of the molecule down in order to melt

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What is the job of cellular respiration?

Answers

Answer:

to break down sugar in the presence of oxygen to release energy in the form of ATP

Explanation: i just finished this chapter of the class

Activation energy is:
A. The energy needed to begin breaking the bonds of reactants.
B. None of these.
C. The maximum amount of energy reactants can hold.
D. The energy needed to begin breaking the bonds of products.

Answers

Your answer is most definitely letter a

Activation energy is the energy needed to begin breaking the bonds of reactants. Hence, option A is correct.

What is activation energy?

Activation energy is defined as the minimum amount of energy necessary to initiate a chemical reaction.

Hence, activation energy is the energy needed to begin breaking the bonds of reactants.

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