1. What is the meaning of Avogadro's number?

A. number of grams per one mole of a substance

B. simplest whole-number ratio of a chemical formula

C. whole number ratio that is a multiple of a chemical formula

D. set number of particles in one mole of a substance

Answer:

magnesium  

Explanation:

because zinc does not react with water because it too forms a protective layer of insoluble.

Answer:

Explanation:

Well you didn’t send a picture of the question but h2O is water so. If the questions answer has a option of water then pick that one

Answer:

4 joules

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Explanation:

4 joules.

When it left the table it would have mgh potential energy that would have been converted to kinetic when it hit the floor. If the mass (m) was twice the energy would have been twice.

Answer:

Q = 1698.51 J

Explanation:

Given that,

Mass of water, m = 63.4 grams

It changes temperature from 22.3C to 28.7C.

We need to find the heat involved. The heat involved due to the change in temperature is given by :

[tex]Q=mc\Delta T[/tex]

Where

c is the specific heat of water, c = 4.186 joule/gram °C

So,

[tex]Q=63.4 \times 4.186 \times (28.7- 22.3)\\\\Q=1698.51\ J[/tex]

So, 1698.51 J of heat is involved.

Answer:

6

Explanation:

C[tex]_6[/tex]H[tex]_{12}[/tex] + O[tex]_2[/tex] → CO[tex]_2[/tex] +H[tex]_2[/tex]O + heat can be balanced as C[tex]_6[/tex]H[tex]_{12}[/tex] + 6O[tex]_2[/tex] → 6CO[tex]_2[/tex] +6 H[tex]_2[/tex]O + heat. Therefore, the correct option is option C.

Combustion is a chemical reaction that often involves the presence of oxygen and produces light and heat within the form of flames. Because of the physical characteristics of the chemical process and the fact that more energy is produced than can be released through the surrounding medium, the rate or speed with which the substances that react combine is high. As a result, the ambient temperature about the reactants is increased, accelerating the reaction even further.

A lit match is a common illustration of a combustion reaction. A flame is produced when a match strikes something because friction warms the head of the match to a temperature where the chemicals respond by creating additional heat than can be released into the atmosphere. C[tex]_6[/tex]H[tex]_{12}[/tex] + O[tex]_2[/tex] → CO[tex]_2[/tex] +H[tex]_2[/tex]O + heat can be balanced as C[tex]_6[/tex]H[tex]_{12}[/tex] + 6O[tex]_2[/tex] → 6CO[tex]_2[/tex] +6 H[tex]_2[/tex]O + heat

Therefore, the correct option is option C.

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Explanation:

sodium has a positive charge and chlorine has a negative charge a negative and a positive charge you automatically for an ionic bond therefore the chlorine has to have a negative one charge

Answer:

amine

Explanation:

We have to bear in mind that amines are basic compounds. This idea will be very important in attempting to answer this question.

So, when she adds 5% HCl solution in order to extract the organic layer, the amine forms a hydrochloride salt which is contained in the aqueous layer.

The addition of a base such as NaOH leads to the formation of a white precipitate of the amine.

Answer:

Higher the salinity, more is the density.

Explanation:

Answer:

Thermal Conductor

Explanation:

Answer:

Vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system.

Explanation:

Answer:

Explanation:

When a salt is dissolved , it increases  the boiling point . Increase in boiling point depends upon number of ions . So it is a colligative property .

.19 m AgNO₃ . Each molecule  will ionize into two ions . So effective molar concentration is 0.19 x 2 = .38 m

0.17 m CrSO4.Each molecule  will ionize into two ions . So effective molar concentration is 0.17 x 2 = .34 m

0.13 m Mn(NO₃)₂. Each molecule  will ionize into three  ions . So effective molar concentration is 0.13 x 3 = .39 m

0.31 m Sucrose(nonelectrolyte). Molecules will not ionize . So effective molar concentration is 0.31 x 1 = .31 m

Higher the molar concentration , greater the depression in boiling point .

So lowest boiling point is 0.13 m Mn(NO₃)₂.

second highest  boiling point is 0.19 m AgNO3.

Third lowest boiling point is 0.17 m CrSO4

Highest boiling point or lowest depression 0.31 m Sucrose.

a . 4

b .  1

c . 2

d . 3

Answer:

a

Explanation:

because you need to add 2 to to hf to make it equal to h2

The complete question is shown in the image attached to this answer.

Answer:

C

Explanation:

Let us quickly remember that the EMF of a cell under non standard conditions in given by the Nernst equation.

This equation states that;

E = E°cell - 0.592/n log Q

Where

E = EMF under non standard conditions

E°cell= standard EMF of the cell

n = number of electrons transferred

Q = reaction quotient

If the reaction quotient is greater than 1 then cell potential is less than the standard cell potential.

The cell that generates the lowest cell potential is the cell depicted in option C because Q has the greatest positive value(Q<1).

The cell potential is the redox potential that measures the acquired to lost electrons at the electrodes. The lowest cell potential is generated by cell C with 0.5 M.

EMF is the electromotive force that is the total of the electric potential difference produced at the half cells of the galvanic cell (electrochemical cell).  

EMF of the cell is given as,

[tex]\rm E = \rm E^{\circ} - \dfrac{0.592}{n}\; log Q[/tex]

Here, E is the electromotive force, [tex]\rm E^{\circ}[/tex] is the standard EMF, n is the number of the transferred electrons, and Q is the reaction quotient.

When the reaction quotient (Q) is greater than 1 then, cell potential will be less than standard cell potential.

Therefore, cell C with 0.5 M and Q > 1 is a similar cell.

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Answer:

the earth would be covered in ice and we would not be able to survive as there is not natural insulation

Answer:

Molefraction is the ratio of the number of moles of solute and total number of moles in solution. Moles = (given mass) / (molar mass) = 1000/18 = 55.5 moles. Therefore 1/(55.5+1) = 0.017. Molefraction of solute in 1 m aqueous solution is 0.017.

Explanation:

Answer:

The approximate age of the igneous rock is [tex]7.042\times 10^{6}[/tex] years.

Explanation:

Chemically speaking, the Uranium-235 decays to form Lead-207 throughout time. All isotopes decay exponentially by means of the following model:

[tex]m(t) = m_{o}\cdot e^{-\frac{t}{\tau} }[/tex] (1)

In addition, we can determine the time constant of the former isotope in terms of its half life, that is:

[tex]\tau = \frac{t_{1/2}}{\ln 2}[/tex] (2)

Where:

[tex]m_{o}[/tex] - Initial mass of Uranium-235, in atoms.

[tex]m(t)[/tex] - Current mass of Uranium-235, in atoms.

[tex]\tau[/tex] - TIme constant, in years.

[tex]t_{1/2}[/tex] - Half-life of Uranium-235, in years.

Please remind that a 1 : 1 ratio of Uranium-235 to Lead-207 atoms means that current mass of Uranium-235 is a half of its initial mass. If we know that [tex]m(t) = 0.5\cdot m_{o}[/tex] and [tex]t_{1/2} = 7.04\times 10^{8}\,yr[/tex], then the approximate age of the igneous rock is:

[tex]\tau = \frac{7.04\times 10^{8}\,yr}{\ln 2}[/tex]

[tex]\tau \approx 1.016\times 10^{9}\,yr[/tex]

[tex]t = -\tau \cdot \ln \left(\frac{m(t)}{m_{o}} \right)[/tex]

[tex]t = -(1.016\times 10^{9}\,yr)\cdot \ln \frac{1}{2}[/tex]

[tex]t \approx 7.042\times 10^{6}\,yr[/tex]

The approximate age of the igneous rock is [tex]7.042\times 10^{6}[/tex] years.

Answer:

An atom

Explanation:

Atom is the smallest indivisible part of an element that retains its chemical identity. An atom contains the protons, neutrons and electrons, which are collectively called SUBATOMIC PARTICLES.

These particles ensure that the chemical identity of an element is maintained. For example, Chlorine has an element has an atom made up of 17 protons, 17 electrons and 18 neutrons. Therefore, chlorine atom is the smallest part of the chlorine element (Cl) that have all properties of that chlorine element.

Answer:

a. Hexanal

Reagent: - Hot acidified potassium permanganate solution.

or : Ammoniacal silver nitrate solution

or : Fehling's solution.

or : Hot acidified potassium dichromate ( VI ) solution.

Some organic compounds can be oxidised to carboxylic acid using suitable oxidising agents. Alkanes can be converted to acid or acid salt by carboxylation reaction and alkyl halides can be converted using Grignard reagent and then hydrolysis.

Carboxylic acids are organic acids containing the functional group COOH. It can be prepared through oxidation  of various of organic compounds.

Hexanal can be converted to hexanoic acid using carboxylation that is reaction with carbon dioxide.

Methyl hexanoate is an ester which can be converted to hexanoic acid by hydrolysis. Reaction with water introduces the H+ group into the ester group COOMe.

1 bromopentane can be converted into hexanoic acid using grignard reagent RMg followed by hydrolysis.

Alcohols can be easily oxidised to acids. Thus, 1-hexanol can be oxidised to hexanoic acid using oxidising agents such as potassium permanganate.

Nitriles can be oxidised to corresponding carboxylic acid using oxidising agents such as chromium chloride or grignard reagent.

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Answer:

Purify drinking water of unwanted

Hope this helps! :D

Answer:

B. A specific mass of a liquid has a fixed volume at room temperature

Explanation:

Matter exists in three states namely; gas, liquid and solid. Each of these states has its own unique property that distinguishes it from others.

- Gases are free moving and do not have a constant or fixed volume.

- Liquids have fixed volume and take on the shape of their container. This means that liquids have a fixed or constant volume at a room temperature.

Based on the above properties of gas and liquid states of matter, "A specific mass of a liquid has a fixed volume at room temperature" is the correct option.

Answer:

It could be the Bbbbbbbbbbb

Answer:

H₂O = 3.56 moles

MgCl₂ = 1.78 moles

Explanation:

Answer:

The type of force is known as cohesive force

Answer:

B 1.17

Explanation:

There is .02 mols of nacl in a .4M solution

so you multiply by the molar weight of NaCl (58.44)

Answer:

C. air pollution absorbs carbon dioxide

Explanation:

Carbon dioxide's role in the greenhouse effect is a major contributor to air pollution. Radiation and heat emanating from the earth's surface need to be released out into the atmosphere. But because carbon dioxide levels are so high, there is an ozone effect on the ground level.

Answer:

The Milky Way

Explanation:

Answer:

Your answer is the Milky WAy!

Brainliest?

Answer:

The formula of the gas produced is[tex]PH_3[/tex], and the balanced equation is :

[tex]Na_3P(s)+3H_2O(l)\rightarrow 3NaOH(aq)+PH_3(g)[/tex]

Explanation:

The chemical reaction between lithium nitride and water gives lithium hydroxide and ammonia gas. The chemical equation of this reaction will be given as:

[tex]Li_3N(s)+3H_2O(l)\rightarrow 3LiOH(aq)+NH_3(g)[/tex]

And when sodium phosphide reacts with water is gives an aqueous solution of sodium hydroxide and hydrogen phosphide gas also called phosphine gas.

The chemical equation of this reaction will be given as:

[tex]Na_3P(s)+3H_2O(l)\rightarrow 3NaOH(aq)+PH_3(g)[/tex]

The formula of the gas produced is[tex]PH_3[/tex], and the balanced equation is :

[tex]Na_3P(s)+3H_2O(l)\rightarrow 3NaOH(aq)+PH_3(g)[/tex]

Answer:

c. 1.58 KJ

Explanation:

I took the test:)

Answer:

1.58 KJ

Explanation: