A.
B.
C.
D.

what could be the correct answer? Help me please

Answer: Quartz

Explanation: I looked it up ;)

Answer:

Titanium; lowest density  

Explanation:

The cart would use the same volume of metal, no matter which one it was made of.

If weight were the only consideration, the company would choose the metal with the lowest density.

The values I find for the metals are

Ti   4.5 g/cm³

Fe  7.9 g/cm³

Zn  7.1  g/cm³

Titanium would be the best metal for this application.

Answer:

Titanium would be the best metal for this application because it is a low density metal that is still strong  and ductile

Explanation:

Answer:

1.2M

Explanation:

Initial Volume 0.05L

Final Volume 0.250L

HCl Molar mass: 36.46 g/mol

M = 6M HCl

Molarity = mol solute /  L of solution

Inital M = Molarity = 6

mol solute = X = unknown

L of Solution = 0.05L

6 = X / 0.05

X = 0.3

X = 0.3/0.25

X = 1.2 M

​  

Answer:

mass=279grams

Explanation:

GIVEN DATA

number of atoms=3.01×10^23

avogadro's number=6.022×10^22

molar mass of iron=56g/moles

TO FIND

mass in gram of iron=?

SOLUTION

by using the formula

mass in gram=(number of atoms÷avogdro's number)×molar mass

mass=(3.01×10^23÷6.022×10^23)×56

mass=0.499×56

mass=27.9grams=28 grams

The spin of electrons is reversed. Hence, option D is correct.

Enthalpy is the sum of the internal energy. and pressure times volume.

During a reaction, the enthalpy of the reactants and the products are not equal which means the spin of electrons is reversed.

Hence, option D is correct.

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Answer:

See the answer below

Explanation:

Aqueous solution of copper II nitrate contains solute of copper II nitrate dissolved in water. The equation for the reaction is as below:

[tex]Cu(NO_3)_2 (s)[/tex] + [tex]H_2O (l)[/tex] --> [tex]Cu(NO_3)_2 (aq)[/tex]

Hence, the solute chemical is copper II nitrate while the solvent is water.

Chemical formula of copper II nitrate - [tex]Cu(NO_3)_2[/tex]

Chemical formula of water - [tex]H_2O[/tex]

Answer:

fddff s

Explanation:

v c dggbgzfx

Answer:

Therefore, 1.00 mole of the gas is present in the container.

Explanation:

The following data were obtained from the question:

Volume (V) = 22.41L

Temperature (T) = 273K

Pressure (P) = 101.325 kPa

Gas constant (R) = 8.31 L.kPa/mol.K.

Number of mole (n) =...?

The number of mole of the gas in the container can obtained by applying the ideal gas equation as illustrated below:

PV = nRT

Divide both side by RT

n = PV /RT

n =101.325  x 22.41 / 8.31 x 273

n = 1.00 mole.

Therefore, 1.00 mole of the gas is present in the container.

Answer:

1 mole of gas is contained in 22.41 liters at 101.325 kPa and 0ᴼC

Explanation:

Ideal gases are a simplification of real gases that is done to study them more easily. It is considered to be formed by point particles, do not interact with each other and move randomly. It is also considered that the molecules of an ideal gas, in themselves, do not occupy any volume.

The pressure, P, the temperature, T, and the volume, V, of an ideal gas, are related by a simple formula called the ideal gas law:  

P*V = n*R*T

where P is the gas pressure, V is the volume that occupies, T is its temperature, R is the ideal gas constant, and n is the number of moles of the gas.

In this case:

Replacing:

1 atm*22.41 L=n* 0.082 [tex]\frac{atm*L}{mol*K}[/tex]*273 K

Solving:

[tex]n=\frac{1 atm*22.41 L}{0.082\frac{atm*L}{mol*K} *273 K}[/tex]

n=1  mole

1 mole of gas is contained in 22.41 liters at 101.325 kPa and 0ᴼC

Answer:

The total number of molecules in each phase stays constant

Explanation:

i just took the test and got it right.

In the dynamic equilibrium between 2 phases, the total number of molecules in each phase stays constant (Option D).

Dynamic equilibrium occurs when the direct and reverse rates are equal and the concentrations remain constant over time.

Which describes two phases in dynamic equilibrium?

In the dynamic equilibrium between 2 phases, the total number of molecules in each phase stays constant (Option D).

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Answer:

5.449 x 10¹⁸ Hz

Explanation:

Energy (E) =Frequency (F) x Plancks constant (h)

F= 3.611x10⁻¹⁵J / 6.626 x 10⁻³⁴ Js⁻¹

F =5.449 x10¹⁸ s⁻¹ or 5.449 x 10¹⁸ Hz

Answer:

1.24mol

Explanation:

m(MgO)=50g

molar mass=40.30g/mol (i search in google coz dosnt have book)

n=mass/molar mass

=50/40.30

=1.24mol

Answer:

49 g/L is the concentration of the acid

Explanation:

Firstly, we proceed to write the equation of reaction.

2NaOH + H2SO4 ——-> Na2SO4 + 2H2O

We can see that 1 mole of the base reacted with two moles of the acid.

kindly note that dm^3 is same as liter

Firstly, we need to get the concentration of the reacted sulphuric acid in g/L

we use the simple titration equation below;

CaVa/CbVb = Na/Nb

From the question;

Ca = ?

Va = 25 cm^3

Cb = 20 g/L

we convert this to concentration in mol/L

Mathematically, that is concentration in g/L divided by molar mass in g/mole

molar mass of NaOH = 40 g/mol

so we have; 20g/L / 40 = 0.5 mol/L

Vb = 50 cm^3

Na = 1

Nb = 2

Where C represents concentrations, V volumes and N , number of moles

Now, substitute the values;

Ca * 25/0.5 * 50 = 1/2

25Ca/25 = 0.5

So Ca = 0.5 mol/L

Now to get the concentration of H2SO4 in g/L

What we do is to multiply the concentration in mol/L by molar mass in g/mol

That would be 0.5 * 98 = 49 g/L

The concentration of the acid in grams per litre is 49g/L

From the question,

We are to determine concentration of the sodium hydroxide solution.

First, we will write a balanced chemical equation for the reaction.

The balanced chemical equation for the reaction is

2NaOH + H₂SO₄ → Na₂SO₄ + 2H₂O

This means,

2 moles of NaOH is required to completely neutralize 1 mole of H₂SO₄

From the formula

[tex]\frac{C_{A}V_{A} }{C_{B}V_{B} }=\frac{n_{A} }{n_{B} }[/tex]

Where

[tex]C_{A}[/tex] is the concentration of acid

[tex]C_{B}[/tex] is the concentration of base

[tex]V_{A}[/tex] is the volume of acid

[tex]V_{B}[/tex] is the volume of base

[tex]n_{A}[/tex] is the mole ratio of acid

[tex]n_{B}[/tex] is the mole ratio of base

From the question

[tex]V_{A}= 25 \ cm^{3}[/tex]

[tex]C_{B} = 20 \ g/dm^{3}[/tex]

Convert this to mol/dm³

Molar mass of NaOH = 40 g/mol

Using the formula

[tex]Concentration\ in \ mol/dm^{3} =\frac{Concentration\ in \ g/dm^{3}}{Molar\ mass}[/tex]

∴ Concentration of the NaOH in mol/dm³ = [tex]\frac{20}{40}[/tex]

Concentration of the NaOH in mol/dm³ = 0.5 mol/dm³

∴ [tex]C_{B} = 0.5 \ mol/dm^{3}[/tex]

and

[tex]V_{B} = 50 \ cm^{3}[/tex]

From the balanced chemical equation

[tex]n_{A} = 1[/tex]

[tex]n_{B} = 2[/tex]

Putting the parameters into the formula, we get

[tex]\frac{C_{A} \times 25}{0.5 \times 50}= \frac{1}{2}[/tex]

Now, this becomes

[tex]2 \times 25 \times C_{A}=0.5 \times 50 \times 1[/tex]

Then, we get

[tex]50 C_{A} = 25[/tex]

∴ [tex]C_{A} = \frac{25}{50}[/tex]

[tex]C_{A} = 0.5 \ mol/dm^{3} = 0.5 \ mol/L[/tex]

Now, we will determine the concentration in g/L

From the formula,

Concentration in g/L = Concentration in mol/L × Molar mass

From the question,

Molar mass of sulfuric acid = 98

∴ Concentration of the acid in g/L = 0.5 × 98

Concentration of the acid in g/L = 49 g/L

Hence, the concentration of the acid in grams per litre is 49g/L

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Answer:

B. CH₅N

Explanation:

The combustion reaction of a compound CₐHₓNₙ with O₂ is:

CₐHₓNₙ + O₂ → a CO₂ + X/2 H₂O + n NO₂

Where 1 mole of CₐHₓNₙ with an excess of O₂ produce a moles of CO₂, X/2 moles of H₂O and n moles of NO₂

Thus, you need to convert the mass of CO₂ and H₂O to moles to find the C:H ratio and determine a possible empirical formula thus:

Moles CO₂ (Molar mass 44g/mol):

44g ₓ (1mol / 44g) = 1 mole CO₂ = 1 mole C

Mole of H₂O (Molar mass 18g/mol):

45g ₓ (1 mol / 18g) = 2.5 moles H₂O = 5 moles H

Thus, in the compound you have 5 moles of H per mole of C, and a possible empirical formula is:

The only structure that meet this C:H ratio

The most likely empirical formula for the one that exemplifies a specimen of the compound containing the element C, H, and N which are completely combusted in oxygen to generate 44g Co2, 45g of H2O, and a little NO2 would be:

B). CH₅N

The reaction of combustion taking place in the compound CₐHₓNₙ using [tex]O_{2}[/tex] (oxygen) would be:

[tex]C_{a} H_{x} N_{n} + O_{2}[/tex]  → [tex]aCO_{2} + X/2 H_{2}O + nNO_{2}[/tex]

In this reaction, 1 mole belonging to [tex]C_{a} H_{x} N_{a}[/tex] having additional [tex]O_{2}[/tex] (oxygen) leads to generating '[tex]a[/tex]' moles of [tex]CO_{2}[/tex] (Carbon dioxide), [tex]X/2[/tex] number of moles of [tex]H_{2}O[/tex](Hydrogen), and n amount of moles of Nitrogen([tex]N[/tex]).

Therefore, it will be required to transform the mass of [tex]CO_{2}[/tex] and [tex]H_{2}O[/tex]  in the form of moles to deduce the ratio C:H to look for the likely empirical formula.

 [tex]CO_{2}[/tex] Moles                                                       (∵ Molar mass [tex]= 44g/mol)[/tex]

= [tex]44g[/tex] × [tex](1mol/44g)[/tex]

[tex]= 1 mole[/tex] of  [tex]CO_{2}[/tex]

[tex]= 1 mole[/tex] of C

[tex]H_{2}O[/tex] Moles                                                   (∵ Molar mass =[tex]18g/mol)[/tex]

[tex]= 45g[/tex] ₓ [tex](1 mol / 18g)[/tex]                          

[tex]= 2.5 moles[/tex]  [tex]H_{2}O[/tex]

[tex]= 5[/tex] [tex]moles of H[/tex] because (H * 2)

∵ The C:H ratio is 1:5 implying that formula would include 5 H moles and 1 C mole. So, CH₅N is the correct option.

Thus, option B is the correct answer.

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Answer:

The pressure will increase due ot expnasion of gasses in a closed sealed tube tube .

Explanation:

Answer:

The pressure inside of a sealed tube will increase if the temperature is raised.

Explanation:

When the temperature of the gas inside the sealed tube is raised, the particles within that tube will start to become faster and faster. Because they are going faster they collide with the sides of the tube faster, therefore increasing the pressure inside the sealed tube.

Hope this helps!

The metallic pan iis most likely going to be used on a stove.

The stove is heating something, and the conductive metallic pan will, well, conduct that heat throughout the entire body of the pan. Doing this will spread the heat to the handle, burning your hands.

Both wood and plastic are insulators, and they do not conduct heat or electricity. They will insulate your hands and protect them from the heat.

Answer: [tex]PCl_5[/tex] is not an ionic compound.

Explanation:

An ionic compound is defined as the compound which is formed when electron gets transferred from one atom to another atom.  The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.

Thus [tex]MoCl_6[/tex], [tex]RbCl[/tex], [tex]PbCl_2[/tex] and [tex]NaCl[/tex] are all ionic compounds.

Covalent compound is defined as the compound which is formed by the sharing of electrons between the atoms forming a compound. These are usually formed when two non-metals react.

Thus [tex]PCl_5[/tex] is a covalent compound as both Phosphorous and chlorine are non metals.

PCl₅ is not an ionic compound. Ionic or electrovalent compounds are formed

through the transfer of electrons in a chemical reaction. Metals and non-

metals mostly form ionic compounds.

Covalent bonding on the other involves the sharing of electrons between

two elements. Non-metals are mostly involved in this type of reaction.

PCl₅ possesses a covalent bond and not ionic as electrons are shared

between two non metals  which are phosphorus and chlorine.

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Answer: [tex]1.6\times 10^4[/tex]

Explanation:

Scientific notation is defined as the representation of expressing the numbers that are too big or too small and are represented in the decimal form with one digit before the decimal point times 10 raise to the power.

For example : 5000 is written as [tex]5.0\times 10^3[/tex]

In division , the result would contain the same number of significant digits as there in the least precise number , thus the answer would have 2 significant digits.

[tex]\frac{1.248\times 10^{-2}}{7.8\times 10^{-7}}=1.6\times 10^4[/tex]

Answer:

it all really depends on the superiors of the government. everyone's so corrupt with their views these days, and let personal opinions rules over what the people want. as a latina, i think we should keep fighting and protesting till we get what we really deserve.

Explanation:

Answer:

A) H2O2

Explanation:

Hydrogen peroxide is written as H2O2, which is the chemical formula of the compound, but this can be simplified. Since both H and O have the subscript of 2, they can be simplified to 1, so the empirical formula for H2O2 would be just H and O together (Brainly won't let me say the empirical form because it has the same spelling as a swear word). Thus, the empirical formula and chemical formula are different.

In the case of the other options, they are all in their simplest form and cannot be simplified further, so they are already in their empirical form, so both the chemical form and empirical form are the same.

Answer:

The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]

Explanation:

Molarity is a way of expressing the concentration of solutions and indicates the number of moles of solute dissolved per liter of solution.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution.:

[tex]Molarity (M)=\frac{number of moles of solute}{volume}[/tex]

Molarity is expressed in units ([tex]\frac{moles}{liter}[/tex]).

Then, the number of moles of solute can be calculated as:

number of moles of solute= molarity* volume

So, in this case, the final concentration can be calculated as:

[tex]Final molarity (M)=\frac{Total number of moles of solute}{Total volume}[/tex]

where, being 65 mL=0.065 L, 125 mL=0.125 L and 190 mL=0.190 L (because 1000 mL= 1 L):

Replacing:

[tex]Final molarity (M)=\frac{0.324595 moles}{0.190 L}[/tex]

Final molarity ≅ 1.71 [tex]\frac{moles}{liter}[/tex]

The molar concentration of the final solution is 1.71 [tex]\frac{moles}{liter}[/tex]

Answer: a)  Sn 2+  

Explanation:A reducing agent is a substance  that can be oxidized when it loses electrons while An oxidizing agent is a substance that is reduced when it gains   electrons.

 Considering  Cu 2+,   Fe 3+, Al 3+, Here,  Cu 2+ can  be reduce to its Copper metal, same for  Al 3+ to Aluminium  metal  and Fe 3+  to Fe 2+ ion  and will not be oxidized further since they are in their most oxidized states. The three ions are acting as only oxidizing agents.

while Sn 2+ can be oxidized to become Sn 4+ and also  be reduced to become Sn metal  acting as a reducing agent and an oxidizing agent.

Answer:

A.) -5448 kJ/mol

Explanation:

I got it correct on founders edtell

Some Energy is released into the environment as heat

Explanation:

Answer:

Explanation:

pH = − log [H+] , we can solve for [H+] as,

− pH = log [H+] ,

[H+] = 10^−pH,

so PH =2.4 in you case is

[H+] = 10^-2.4 =0.00398

The option are not correct it looks

Answer: orbitals supernumerary

Explanation:

Answer:

both S orbital and p orbitals

Explanation:

took the exam got the question right.

Answer:

The answer is protons and nuetrons

Explanation:

Answer:

1) Conditions necessary for rusting are:

a) Presence of atmospheric oxygen or air

b)Presence of water or moisture

2) For protecting the iron gate, we can paint it because the paint will coat it and protect it from atmospheric oxygen and water.

3) Magnesium, Carbon and Oxygen (MgCO₃)

Answer:

17.1 Liters

Explanation:

It's a gas law question (more specifically a Charles's Law question). Formula is V1/T1 = V2/T2. You're given V1 and T1 and T2. However, in order to use the equation, temperature needs to be in Kelvins (by subtracting the degrees C from 273) for the numbers to work (among other reasons, the 0 degrees C will always give you an answer of zero or undefined). Placing all temps in kelvins makes the answers come out right. So 20L/273K = xL/233K gives you the answer when you cross-multiply.

Considering the Charles's law, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has  17.07 L at -40.0 °C, assuming pressure is held constant.

The gas laws are a set of chemical and physical laws that allow determining the behavior of gases in a closed system. The parameters evaluated in these laws are pressure, volume, temperature and moles.

Charles's law is one of the gas laws. It relates the volume and the temperature of a certain quantity of ideal gas, kept at a constant pressure.

This law states that, at constant pressure, the volume of a gas is directly  proportional to its temperature. In other words, for a given sum of gas at constant pressure, as the temperature increases, the volume of the gas increases, and as the temperature decreases, the volume of the gas decreases.

Mathematically, Charles's law says that the quotient that exists between the volume and the temperature will always have the same value:

[tex]\frac{V}{T}=k[/tex]

Being an initial state 1 and a final state 2, it is true:

[tex]\frac{V1}{T1}=\frac{V2}{T2}[/tex]

In this case, you know:

Replacing:

[tex]\frac{20 L}{273 K}=\frac{V2}{233 K}[/tex]

Solving:

[tex]V2=233 K x\frac{20 L}{273 K}[/tex]

V2=17.07 L

Finally, a weather balloon calibrated at 0.00 °C to have a volume of 20.0 L has  17.07 L at -40.0 °C, assuming pressure is held constant.

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