Question 2: thanks!!!

Answer:

What

You cant just send notes you also have to say where you are and which book you are using because others are different

Answer:

A) The amount in grams of Li₃N produced is 1.243 g

B) N₂, is the limiting reagent

The mass of the non-limiting reagent, Li, remaining after the reaction is completed is 1.757 g

Explanation:

The given parameters are;

The mass of Li(s) = 2.5 grams

The mass of N₂ (g) = 0.5 grams

The chemical equation for the reaction can be presented as follows;

6 Li (s) + N₂ (g) → 2 Li₃N

Therefore, 6 moles of Li reacts with 1 mole of N₂  to produce 2 moles of Li₃N

The molar mass of Li = 6.941 g/mol

The molar mass of N₂ = 28.0134 g/mol

The number of moles of a reactant or product, n is given by the relation;

n = Mass of substance/(Molar mass of the substance)

For lithium, Li, n = 2.5/6.941 = 0.3602 moles

For Nitrogen gas, N₂, n = 0.5/28.0134  = 0.01785 moles

A) Given that 1 mole of  N₂ to produces 2 moles of Li₃N

0.01785  moles of  N₂ will produces 2×0.01785 = 0.0357 moles of Li₃N

The molar mass of Li₃N = 34.83 g/mol

The mass of Li₃N = 34.83 g/mol × 0.0357 moles = 1.243 g

B) 6  moles of Li reacts with 1 mole of N₂ to produce 2 moles of Li₃N

0.3602 moles will reacts with 1/6×0.3602 = 0.06003 mole of N₂

Therefore, N₂, is the limiting reagent and we have;

0.01785  moles of  N₂ will react with 6×0.01785 = 0.1071  moles of Li

The number of of moles of Li left = 0.3602 - 0.1071 =0.2531 moles

The mass of lithium left = 0.2531 moles × 6.941 g/mol = 1.757 g

The mass of lithium remaining after the reaction is completed = 1.757 g.

One mole of H₂S gas contains 6.022 × 10²³ H₂S molecules. Hence, 2.50 mol of H₂S contains 1.50 × 10²⁴ molecules. Thus, option A is correct.

Any substance containing 6.022 × 10²³ number of atoms is called one mole of that substance. This number is called Avogadro number. Thus, one mole every elements contains Avogadro number of atoms.

Similarly a compound is made of molecules. One mole of a compound contains 6.022 × 10²³ number of molecules. The mass of a compound with Avogadro number of molecules is called its molar mass.

As any other compound, one mole of H₂S contains 6.022 × 10²³ molecules. Therefore, the number of molecules in 2.50 moles of H₂S is :

2.50 moles × 6.022 × 10²³ molecules/mol =  1.50 × 10²⁴molecules

Hence, the number of molecules present in 2.50 moles of H₂S is  1.50 × 10²⁴.

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Answer:

The shape of a molecule based on the number of electron pairs on the valence shell of its central atom

Explanation:

The improvement of the Sidgwick-Powell theory came to be known as the Valence Shell Electron Pair Repulsion theory (VSEPR). This theory approaches the determination of molecular shape from the perspective of the number of electron pairs on the valence shell of the central atom in the molecule.

Electron pairs on the valence shells of atoms leads to repulsion. Repulsion between two lone pairs is greater than repulsion between a lone pair and a bond pair which is also greater than repulsion between two bond pairs.

Lone pairs cause more repulsion, hence they distort molecules from the ideal shape predicted based on their electron domain geometry.

Answer:

Only 2moles are produced from it

The correct answer is D. The native species would not have to  compete for necessary resources

Explanation:

Invasive species, which include any living organism that is not native in an ecosystem, contribute to the extinction of native species as they compete for resources such as food, shelter, etc. with native species. For example, the  Asian Carp, which was introduced to lakes in the U.S. consumes plankton, which reduces the amount of plankton available for native fish. In this context, by removing invasive species native species would not have to compete for resources and their chances to extinct will fall.

Answer:

true

Explanation:

The standard laboratory rule is to always add acids or bases to solvent and not the other way round.

The dissolution of concentrated acids/bases in solvents (water) generates heat energy. Thus, if the solvent is added to them, a layer of hot weak acid or base will be formed and this will boil and spray around, causing an explosion.

On the other hand, if acid/base is added to solvents, they flow into the solvents and get diluted immediately without any boiling taking place. Hence, it is safe to add acid/base to solvents and not the other way round.

Answer:

[tex]\huge\boxed{94.9\ grams}[/tex]

Explanation:

Relative formula mass of phosphate:

=> [tex]PO_{4}[/tex]  [Ignoring the charge on it]

Atomic mass of P = 31.0 grams, O = 15.9 grams

=>  30.97 + 4(15.9)

=> 30.97 + 63.9

=> 94.87

≈ 94.9 grams [To nearest tenth]

Answer:

[tex]\huge \boxed{\mathrm{D. \ 94.9 \ grams}}[/tex]

Explanation:

Phosphate chemical formula is given as,

[tex]\sf PO_4[/tex]

There is one phosphorus atom and four oxygen atoms.

Atomic mass of Phosphorus [tex]\sf P[/tex] = 30.974 grams

Atomic mass of Oxygen [tex]\sf O[/tex] = 15.999 grams

[tex]\Rightarrow 30.974 + 4(15.999)[/tex]

[tex]\Rightarrow 30.974+ 63.996[/tex]

[tex]\Rightarrow 94.97[/tex]

The relative formula mass of phosphate [tex]\sf PO_4[/tex] is 94.9 grams.

The correct answer is Sr-84. The lightest specie is the most deflected while the heaviest specie is the least deflected.

In mass spectroscopy, chemical substances can be identified by looking at their respective mass-to-charge ratios of gaseous ions in electric and magnetic fields. The is achieved using a mass spectrometer.

The lightest specie undergoes the greatest deflection while the heaviest specie undergoes the heaviest deflection accordingly in a mass spectrometer.

In this case, Sr-84, is the lightest specie hence it should be the least deflected specie.

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Solution:-1

[tex]\\ \sf\longmapsto E=hv[/tex]

Solution:-2

[tex]\boxed{\sf \lambda=\dfrac{c}{v}}[/tex]

[tex]\\ \sf\longmapsto v=\dfrac{c}{\lambda}[/tex]

[tex]\\ \sf\longmapsto v=\dfrac{3\times 10^8m/s}{3000\times 10^{-10}m}[/tex]

[tex]\\ \sf\longmapsto v=0.001\times 10^{18}s^{-1}[/tex]

[tex]\\ \sf\longmapsto v=1.0\times 10^{15}s^{-1}[/tex]

Now

[tex]\\ \sf\longmapsto E=hv[/tex]

[tex]\\ \sf\longmapsto E=6.626\times 10^{-34}Js\times 1.0\times 10^{15}s^{-1}[/tex]

[tex]\\ \sf\longmapsto E=6.6\times 10^{-19}J[/tex]

Alkynes are called the hydrocarbons. Ethyne is an important alkyne which is used in oxyacetylene gas cutting. A hydrocarbon containing a carbon-carbon triple bond is the alkyne. The correct option is C.

In organic chemistry, an alkyne is defined as the unsaturated hydrocarbon containing at least one carbon-carbon triple bond. The alkynes are unsaturated hydrocarbons and their general formula is CₙH₂ₙ₋₂ and the triple bond is known as the acetylene bond.

Many alkynes are found in nature. Ethyne is the first member of the alkyne family in which two carbon atoms are connected by a triple bond. Almost all alkynes are also found to be hydrophobic in nature.

Alkynes show three types of isomerism like chain isomerism, position isomerism and functional isomerism. The triple bond present in the alkynes is its functional group.

Thus the correct option is C.

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Answer:

The system will shift to the left producing more moles of gases trying to maintain the original pressure of the system

Explanation:

Based on LeChatelier's principle, a change in temperature, pressure, volume or concentration on a system result in an opposing change trying to maintain the initial equilibrium conditions.

In the reaction:

N₂(g) + 3H₂(g) ⇄ 2NH₃(g)

4 moles of gas reacts producing 2 moles of gas.

In a gas reaction, the system will try to maintain the total pressure.

If the volume of the container increases, the system will shift to the side of the reaction that has more moles of gases in order to maintain the pressure.

That means if in the reaction the volume of the container increase from 2.0L to 4.0L the system will shift to the left producing more moles of gases trying to maintain the original pressure of the system.

Answer:

Mg2+

Explanation:

o2- =2,8

mg2+ =2,8

na+ =2,8

f- =2,8

since they are all same it depends on protons.

mg2+ has least protons

Scientific Approach is to identify a problem and finding solution to the problem. There are various steps in scientific approach to solve a problem,

Identify the problem

Analyze the impact

Find available solution

Evaluate different alternative solutions

Choose the best alternative

Apply the solution to the problem

Measure the results

Lets say there is a fire at some place.

There are various solution available, the fire can be slowed down by water, using fire extinguisher or sand.

The best alternative is to use fire extinguisher.

The fire is vanished after the use of fire extinguisher.

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Answer:

C

Explanation:

The ions are first accelerated electrically, and then bended magnetically to sort them and record them.

Answer:

Explanation:

a )

Zn = Zn²⁺ + 2e   ( oxidation reaction )

Fe³⁺ + 3e = Fe( s ) ( reduction reaction )

b )

[ Zn = Zn²⁺ + 2e ] x 3

[ Fe³⁺ + 3e = Fe( s ) ] x 2

-------------------------------------------------------------------

3 Zn + 2 Fe³⁺ + 6e = 3 Zn²⁺ + 2 Fe ( s ) + 6e

3 Zn + 2 Fe³⁺  = 3 Zn²⁺ + 2 Fe ( s )

Answer:

Those aspects which are something a village needs are specified beneath.

Explanation:

Answer:

Quick you said:

-Purpose/Question

Ask a question.

-Research

Conduct background research. Write down your sources so you can cite your references. In the modern era, a lot of your research may be conducted online. Scroll to the bottom of articles to check the references. Even if you can't access the full text of a published article, you can usually view the abstract to see the summary of other experiments. Interview experts on a topic. The more you know about a subject, the easier it will be to conduct your investigation.

-Hypothesis

Propose a hypothesis. This is a sort of educated guess about what you expect. It is a statement used to predict the outcome of an experiment. Usually, a hypothesis is written in terms of cause and effect. Alternatively, it may describe the relationship between two phenomena. One type of hypothesis is the null hypothesis or the no-difference hypothesis. This is an easy type of hypothesis to test because it assumes changing a variable will have no effect on the outcome. In reality, you probably expect a change but rejecting a hypothesis may be more useful than accepting one.

-Experiment

Design and perform an experiment to test your hypothesis. An experiment has an independent and dependent variable. You change or control the independent variable and record the effect it has on the dependent variable. It's important to change only one variable for an experiment rather than try to combine the effects of variables in an experiment. For example, if you want to test the effects of light intensity and fertilizer concentration on the growth rate of a plant, you're really looking at two separate experiments.

-Data/Analysis

Record observations and analyze the meaning of the data. Often, you'll prepare a table or graph of the data. Don't throw out data points you think are bad or that don't support your predictions. Some of the most incredible discoveries in science were made because the data looked wrong! Once you have the data, you may need to perform a mathematical analysis to support or refute your hypothesis.

-Conclusion

Conclude whether to accept or reject your hypothesis. There is no right or wrong outcome to an experiment, so either result is fine. Accepting a hypothesis does not necessarily mean it's correct! Sometimes repeating an experiment may give a different result. In other cases, a hypothesis may predict an outcome, yet you might draw an incorrect conclusion. Communicate your results. The results may be compiled into a lab report or formally submitted as a paper. Whether you accept or reject the hypothesis, you likely learned something about the subject and may wish to revise the original hypothesis or form a new one for a future experiment.

Answer:

Explanation:

To solve the question above we must first find the pH of the solution using the formula

pH + pOH = 14

pOH = 3.1

So we have

pH + 3.1 = 14

pH = 14 - 3.1

pH = 10.9

Since it's pH is 10.9 the solution is a basic solution since it's pH lies in the basic region.

Hope this helps you

Answer:

ECovalent bond, in chemistry, the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic attraction of their nuclei for the same electrons. ... Silicon, carbon, germanium, and a few other elements form covalently bonded solids.



Please make me Brain liest );

Answer:

The answer is "Option B"

Explanation:

when we react with FeCl, iron, and chloride to both the electrolysis. So, iron is charged positive ion, as well as passes to the negative, is cathode electrode. But there is a decrease in the cathode.

The equation can be defined as follows:

[tex]FeCl_2[/tex] [tex]\longrightarrow[/tex][tex]Fe + Cl_2[/tex]

In the above equation, when the iron chloride electrolysis solution, it will give the iron(II) and the chlorine. This process happens when the hydrogen chloride solution at a temperature of about 90 ° C.

Answer: D

Explanation: As Fe is positive charged while chlorine is negative charged.

(D) is correct. As iron moves to negative and it get reduce as negative electrode is cathode

Answer:

37%+24%+23%=84% , i wish my answer is correct

Answer:

An ionic bond is a chemical bonding involving the attraction between oppositely charged ions

Explanation:

On the periodic table, elements from group 1 and 7 are attracted to each other and when they bond, it's called ionic bonding. This is because of their valence electrons and ions.

Answer:

Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, and is the primary interaction occurring in ionic compounds. It is one of the main types of bonding along with covalent bonding.

Answer:

0.2 moles de SO₂

Explanation:

La reaccción es:

2H₂S (g) +  3O₂ (g)  →  2SO₂ (g)  +  2H₂O(g)

Asumimos que tenemos 0.250 moles de sulfuro y 0.3 moles de oxígeno.

En primer lugar tenemos que averiguar el reactivo limitante.

Si 2 moles de sulfuro de hidrógeno reaccionan con 3 moles de oxígeno, según la reacción.

Entonces 0.250 moles, reaccionarían con (0.250 . 3) /2 = 0.375moles

Tenemos entonces 0.3 moles de oxígeno y necesitamos 0.375 (no nos alcanza). Por lo tanto el O₂ es el limitante y ahora podemos calcular el producto formado. La ecuación nos dice:

3 moles de oxígeno pueden producir dos moles de SO₂

Entonces 0.3 moles (que son los que tenemos) de O₂ producirían:

(0.3 . 2) /3 = 0.2 moles de SO₂

Answer: False

Explanation:

It is not that it must have fossil fuels only because car can also work on hydro power and water. So it should be energy.

must click thanks and mark brainliest

Its fact that a car can also run on water and hydropower means that it does not necessarily need fossil fuels. Therefore,  a car engine must have fossil fuels to work is false.

An extracted and burnt fossil fuel is a hydrocarbon-containing substance that naturally originated in the Earth's crust from the remnants of extinct plants and animals.

Natural gas, crude oil, and coal are the three primary fossil fuels. Fossil fuels are resources that resemble rocks, gases, or liquids that are burnt to produce electricity.

They are employed as energy sources in the electrical and transportation industries and include coal, natural gas, and oil. They are also a major contributor to global warming pollution.

Fossil fuels are used to generate energy, they are burnt to provide heat in homes, electricity in big power plants, and power for engines.

Thus,  a car engine must have fossil fuels to work is false.

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Answer:

Sodium hydroxide + ammonium chloride — Sodium chloride + ammonia gas + water

Explanation:

NaOH + NH4Cl — NaCl + NH3 + H2O

Answer:

i) b

ii) c

Explanation:

Please see attached picture for full solution.

Answer:

Each component in a mixture contributes a fraction to the total number of moles in the mixture. This fraction is called the _mole_ fraction of the component. In a mixture of gases, this fraction is proportional to the _mole_ pressure for each gas present.

Answer:

In chemistry the reactivity series is an empirical, calculated, and structurally analytical progression of a series of metals, arranged by their "reactivity" from highest to the lowest.

Answer:

In a reactivity series, the most reactive element is placed at the top and the least reactive element at the bottom. More reactive metals have a greater tendency to lose electrons and form positive ions.

A reactivity series of metals could include any elements. For example,

A list of elements from most reactive to least reactive: potassium, sodium, lithium, calcium, magnesium, aluminum, zinc, iron, copper, silver, and gold.

A good way to remember the order of a reactivity series of metals is to use the first letter of each one to make up a silly sentence. For example, People Say Little Children Make A Zebra Ill Constantly Sniffing Giraffes.

Observations of the way that these elements react with water, acids, and steam enable us to put them into this series.

The tables show how the elements react with water and dilute acids:

Element Reaction with water

Potassium Violently

Sodium Very quickly

Lithium Quickly

Calcium More slowly

Element Reaction with dilute acids

Calcium Very quickly

Magnesium Quickly

Zinc More slowly

Iron More slowly than zinc

Copper Very slowly

Silver Barely reacts

Gold Does not react

Note that aluminum can be difficult to place in the correct position in the reactivity series during these experiments. This is because its protective aluminum oxide layer makes it appear to be less reactive than it really is. When this layer is removed, the observations are more reliable.

Non-metals in the reactivity series

It is useful to place carbon and hydrogen into the reactivity series because these elements can be used to extract metals.

Here is the reactivity series including carbon and hydrogen:

A list of elements from most reactive to least reactive: potassium, sodium, lithium, calcium, magnesium, aluminum, carbon, zinc, iron, hydrogen, copper, silver, and gold.

Note that zinc and iron can be displaced from their oxides using carbon but not using hydrogen. However, copper can be extracted using carbon or hydrogen. Displacement reactions of metal oxides

A more reactive metal will displace a less reactive metal from a compound. The thermite reaction is a good example of this. It is used to produce white-hot molten (liquid) iron in remote locations for welding. A lot of heat is needed to start the reaction, but then it releases an incredible amount of heat, enough to melt the iron.

aluminium + iron(III) oxide → iron + aluminium oxide

2Al + Fe2O3 → 2Fe + Al2O3

Because aluminum is more reactive than iron, it displaces iron from iron(III) oxide. The aluminum removes oxygen from the iron(III) oxide:

iron is reduced

aluminum is oxidized

Reactions between metals and metal oxides allow us to put a selection of metals into a reactivity series. Using metals A, B, and C:

Metal A Metal B Metal C

A oxide X Displaces A Displaces A

B oxide No reaction X No reaction

C oxide No reaction Displaces C X

Metal A cannot displace either B or C - so it must be the least reactive and be at the bottom of this reactivity series.

Metal B displaces both A and C - so it must be the most reactive and be at the top of this reactivity series.

Metal C displaces A but cannot displace B - so it must be more reactive than A but less reactive than B, and be in between them in this reactivity series.

In general, the greater the difference in reactivity between two metals in a displacement reaction, the greater the amount of energy released.

Aluminum is much higher than iron in the reactivity series, so the thermite reaction releases a lot of energy. Magnesium is very high in the reactivity series, and copper is very low - so the reaction between magnesium and copper oxide is more violent.

Therefore, the order is:

A list of letters from most reactive to least reactive: B, C and A,

Displacement reactions of solutions

A more reactive metal will displace a less reactive metal from a solution of one of its salts. For example:

magnesium + copper(II) sulfate → copper + magnesium sulfate

Mg(s) + CuSO4(aq) → Cu(s) + MgSO4(aq)

In this reaction, the blue color of the copper(II) sulfate fades as it is used up (magnesium sulfate solution is colorless). We would also see copper metal forming.

Reactions between metals and solutions of metal salts allow us to put a selection of metals into a reactivity series. Using metals J, K, and L:

Metal J Metal K Metal L

J sulfate X No reaction No reaction

K sulfate Displaces K X Displaces K

L sulfate Displaces L No reaction X

Metal J displaces both K and L - so it must be the most reactive and be at the top of this reactivity series.

Metal K cannot displace either J or L - so it must be the least reactive and be at the bottom of this reactivity series.

Metal L displaces K but cannot displace J - so it must be more reactive than K but less reactive than J, and be in between them in this reactivity series.

- sorry I'm late and it's is long -_-||