how many atoms are in 23 moles of oxygen ?

The boiling point (in C) of a 0.743 m  aqueous solution of KCI : 100.7608°C

Solutions from volatile substances have a higher boiling point and lower freezing points than the solvent  

ΔTb = Tb solution - Tb solvent  

ΔTb = boiling point elevation  

[tex]\large {\boxed {\boxed {\bold {\Delta Tb \: = \: Kb.m}}}[/tex]

For electrolyte solutions there is a van't Hoff factor = i  

i = 1 + (n-1) α  

n = number of ions from the electrolyte  

α = degree of ionization, strong electrolyte α = 1, for non electrolytes i = 1  

KCl⇒K⁺+Cl⁻⇒ electrolyte  solution(2 ions K⁺ and Cl⁻),  strong electrolyte α = 1

ΔTb=Kb.m.i

i = 1 + (n-1) α  

i=1+(2-1).1=2

Kb for water (solvent) : 0.512 °C kg/mol

molal KCl = 0.743 m

The boiling point of solution :

[tex]\tt Tb-100=0.512\times 0.743\times 2\\\\Tb-100=0.7608\\\\Tb=100.7608^OC[/tex]

The correct answer is 100.761.

Answer:

c

Explanation:

Answer:

b

Explanation:

Answer:

does friction talks ? friction is a oppossing force tho

Law of Conservation of mass: Mass cannot be created nor destroyed. Reference: Antoine Lavoisier – By carefully weighing the reactants & products of chemical reactions. The laws of chemical combination describe the basic principles obeyed by interacting atoms and molecules, interactions that can include many different combinations that happen in many different ways. This amazing diversity of interactions allows for an astounding variety of chemical reactions and compounds. The most fundamental concept in chemistry is the law of conservation of mass, which states that there is no detectable change in the quantity of matter during an ordinary chemical reaction. Modern chemistry is based on several fundamental laws, including:

The concentration of the HCI solution : 0.767 M

Reaction

Na₂CO₃ (aq) + 2 HCl (aq) → 2 NaCl (aq) + CO₂ (g) + H₂O (l)

mass of CO₂ = 11.1 g

mol of CO₂ (MW= 44,01 g/mol) :

[tex]\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{11.1}{ 44,01}\\\\mol=0.252[/tex]

From the equation above, mol ratio of HCl : CO₂ = 2 : 1, so mol HCl :

[tex]\tt mol~HCl=\dfrac{2}{1}\times 0.252=0.504[/tex]

Molarity shows the number of moles of solute in every 1 liter of solution.

[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]

The molarity of unknown HCl :

mol=n=0.504

volume=V=657 ml=0.657 L

[tex]\tt M=\dfrac{0.504}{0.657}\\\\M=0.767[/tex]

Answer:

3.5x1024 3.5 x 10 24 carbon dioxide molecules weighs 256 g.

fraction of the volume of the atom that is taken up by the nucleus is 1.07x10⁻¹³Å³

Sphere volume is calculated by formula =

V=4/3(πr³) , V is volume , r is radius
Radius = diameter/2

Radius of atom = 2/2=1

Radius of nucleus = (9.50x10⁻⁵)/2 = 4.75x10⁻⁵

now we may calculate the volume for the atom and the nucleus

atom volume = (4/3) × 3.14 × (1 )³ = 4.186 ų

nucleus volume = (4/3) × 3.14 × (4.75× 10⁻⁵)³ = 4.48 × 10⁻¹³Å³

now the fraction of volume of the atom that is taken up by the nucleus:

fraction = nucleus volume / atom volume 

fraction =4.48 × 10⁻¹³/4.186 = 1.07x10⁻¹³Å³

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Answer: Yes we can extract all the lithium from the amount of compound we have.

Explanation:

To calculate the moles :

[tex]moles=\frac{\text {given mass}}{\text {Molar mass}}[/tex]

[tex]\text{Moles of} Li=\frac{150g}{7g/mol}=21.4moles[/tex]

[tex]\text{Moles of} Li_2O=\frac{675g}{30g/mol}=22.5moles[/tex]

[tex]2Li_2O\rightarrow 4Li+O_2[/tex]

According to stoichiometry :

2 moles of [tex]Li_2O[/tex] produce 4 moles of [tex]Li[/tex]

Thus 22.5 moles of [tex]Li_2O[/tex] will produce=[tex]\frac{4}{2}\times 22.5=45moles[/tex]  of Li

As 21.4 moles is a lesser quantity than 45 moles, thus it can be produced

Yes, you can extract all the lithium you need from the compound

We'll begin by calculating the mass of lithium, Li in 1 mole of Li₂O. This can be obtained as described below:

1 mole of Li₂O = (2×7) + 16

1 mole of Li₂O = 14 + 16 = 30 g

SUMMARY

30 g of Li₂O contains 14 g of Li.

30 g of Li₂O contains 14 g of Li.

Therefore,

675 g of Li₂O Will contain = (675 × 14)/30 = 315 g of Li.

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Answer:

85g

Explanation:

To convert the moles of a substance to grams we need to know the molar mass of the substance. We, as first, must obtain the molar mass of (NH₄)₂S as follows:

There are 2 atoms of N, 8 of H and 1 of S:

N = 2*14g/mol = 28g/mol

H = 8*1g/mol = 8g/mol

S = 1*32g/mol = 32g/mol

Molar mass: 68g/mol

That means 1 mole of (NH₄)₂S has a mass of 68g.

1.25moles have a mass of:

1.25moles * (68g/mol) =

Answer:

The answer would be

C. The number of neutrons

You're welcome <3

1.)

density is found by [tex]\rho=\frac{m}{V}[/tex]

[tex]\rho=\frac{3.1}{0.35}\\\\ \rho=8.857 g/cm^3[/tex]

2.)

Volume is [tex]lwh[/tex]

7*10*5

V=350[tex]cm^3[/tex]

3.)

using the density formula

[tex]\rho=\frac{m}{V}[/tex]

[tex]\rho=\frac{4.3}{3}[/tex]

[tex]\rho=1.43g/ml[/tex]

4.)

rearrange the density formula for V

[tex]V=\frac{m}{\rho}[/tex]

[tex]V=\frac{58.5}{9.9}\\\\ V=5.909cm^3[/tex]

5.)

rearrange the density formula for [tex]m[/tex]

[tex]m=\rho V\\\\m=(6.7)(5)\\\\m=33.5g[/tex]

True.

However, overpopulation also increases if there is a shortage in the population of consumers. As a result population of producers increase.

Answer:

True (statement is correct)

Explanation:

Yeah, overpopulation occurs when the number of organisms of a species exceeds the ecosystem's carrying capacity. Hence, the given statement is correct (true).

Answer:

1. Objective

2. Objective

3. Opinion

4. Objective

5. Opinion

6. Opinion

7. Opinion (I think.)

8. Opinion (I think.)

Explanation:

answer: it should be false

Answer:

D

Explanation:

Answer:

D) Bacterium

Explanation:

Answer:

35.8.540 its korrect now

If the light completely falls on the two beakers, the degree of hotness increases with respect to time, while if the light is transmitted, the water would gradually cool down.

The effect of transmitted light on temperature is understood by the fact that the intensity of transmitted light became maximum during the process of cooling. While it gets the opposite when the water warms significantly.

According to the context of this question, if all the light reaching the two beakers had been transmitted, the degree of hotness of the water gradually declines. Due to this, the water in the two beakers cool down.

Therefore, the water cools slowly if all the light reaching the two beakers had been transmitted.

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Answer:

Energy can neither be created not be destroyed

Mass too can neither be created nor be destroyed

Both of them remain conserved during any chemical or physical reaction

Some part of them gets transformed to undesired useless form

Hence law of conservation of mass should better be called the law of conservation of mass and energy

I hope helps you and if you consider and want you can give me a Brainly crown

Answer:

I believe it's an example of velocity

Explanation:

This is because 85miles/hour south is giving both magnitude (85miles/hour) and direction (south)

Answer:

B) Kinetic

Explanation:

Kinetic Energy is energy relating to or resulting from motion. Therefore, the answer to this question is B.

Answer:

The answer is option B - Kinetic energy.

Explanation:

The Energy that a moving object has due to its motion is Kinetic Energy.

The influence of various wet chemical treatments on the germanium wafer surface has been examined. The GeO2 part of the native oxide is readily dissolved in water. The solubility of the GeO2 in aqueous solutions and the fast oxidation of germanium makes commonly used silicon treatments nonapplicable due to the relatively high etch rates. In various etching chemistries, the underlying suboxide is not attacked. A hydroxylated suboxide might be an ideal starting surface for ALD, because of its low contribution to electrical thickness. HBr removes even the suboxide and yields a completely oxide-free germanium surface which makes it a candidate surface preparation technique for epitaxial growth. The same result is obtained using a HI dip followed by a DIW rinse. Oxide is growing in CR-air, while in N 2 ambient the surface remains stable.

An oxide is a category of chemical compound that has one or more oxygen atoms as well as another element in its composition such as Li2O, CO2, H2O, etc.

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Bases are substances that can release hydroxide ions or take up hydrogen ions into the water.

Bases are those substances that have a pH above 7. They are bitter. When bases are added to water, they release hydroxide ions. And takes up hydrogen ions. Bases that fall at the pH of 8 are considered weak bases whereas those bases that fall at the pH of 14 are considered strong bases. A few examples of bases are sodium hydroxide, calcium hydroxide, potassium hydroxide, etc.

[tex]NaOH + H _{2}O→ Na ^{ + } + OH ^{ - } [/tex]

Substances that fall within the pH of 7 are considered neutral substances.

Acids are substances that have a pH below 7. They are sour. When acids are added to water they release hydrogen ions. Acids that fall at the pH of 6 are considered weak acids whereas those bases that fall at the pH of 1 are considered strong acids. A few examples of acids are acetic acid, hydrochloric acid, sulphuric acid, nitric acid, etc.

[tex]CH _{3}COOH + H _{2} O→COO ^{ - } + H ^{ + } [/tex]

Therefore, the substances that release hydroxide ions or take up hydrogen ions into the water are known as bases.

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Answer:

D. lysosome

Explanation:

hope it helps :D

sorry if its wrong :/

Answer:

6 orbitals

Explanation:

An atom of mercury will have 6 - orbitals because it can be found on the 6-period in the periodic table of elements.

Orbitals or shells are energy levels in which electrons are placed within an atom.

Let us write the shell notation of the element:

    Hg has 80 electrons:

            K     L    M   N     O   P

            2      8   18    32    18  2

So, we have six orbitals

The wrong Juan did in this investigation is he multiplied by 4 and did not count it for 60 seconds to calculate the heart rate per minute.

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Answer: 32.06 atomic mass units

Explanation:

The metals in the following set which will have equal density are:

So, the correct options are 2,3 and 6.

A substance or object's density can be found out by comparing its mass to volume. Density is calculated using the formula:

[tex]density = \frac{mass}{volume}[/tex]

It is an essential property that the density of the same material remains constant at varied masses and volumes. Since the metal used in both situations is the same and metal has a fixed value of density, the choice with sets of the same metals has equal densities across the possibilities provided.

The complete question is as follows:

To save time you can approximate the initial volume of water to ±1 mL and the initial mass of the solid to ±1 g. For example, if you are asked to add 23 mL of water, add between 22 mL and 24 mL. Which metals in each of the following sets will have equal density?

1. 20.2 g gold placed in 21.6 mL of water and 12.0 g copper placed in 21.6 mL of water.

2. 20.2 g silver placed in 21.6 mL of water and 12.0 g silver placed in 21.6 mL of water.

3. 15.2 g copper placed in 21.6 mL of water and 50.0 g copper placed in 23.4 mL of water.

4. 15.4 g gold placed in 20.0 mL of water and 15.7 g silver placed in 20.0 mL of water.

5. 20.2 g silver placed in 21.6 mL of water and 20.2 g copper placed in 21.6 mL of water.

6. 11.2 g gold placed in 21.6 mL of water and 14.9 g gold placed in 23.4 mL of water.

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Answer:

hope it helps...

Explanation:

Atomic Number as the Basis for the Periodic Law

Assuming there were errors in atomic masses, Mendeleev placed certain elements not in order of increasing atomic mass so that they could fit into the proper groups (similar elements have similar properties) of his periodic table.