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Answer:

12

Explanation:

4x3 is 12

Answer:

To solve this simple expression you must substitute [tex]a[/tex] for the number you are given, so, 3.

4[tex]a[/tex] -> 4 3

Now, when numbers are next to each other like this, they are always multiplied. So, the find the answer you would multiply 4 times 3...

4 x 3 = 12

So, you answer will be 12!

Answer and Explanation:

Since the compound sodium nitrate (NaNO₃) is a strong electrolyte, it dissociates completely into ions when is dissolved in water, as follows:

NaNO₃(s) → Na⁺(aq) + NO₃⁻(aq)

So, the solid compound produces the sodium cation (Na⁺) and the nitrate anion (NO₃-) in the aqueous medium.

Answer:Vinegar

Explanation:

Answer:

0.0344 moles and 1.93g.

Explanation:

Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:

Moles KOH:

15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles

Mass KOH:

0.0344 moles * (56.11g/mol) = 1.93g of KOH

Answer:

SO SORRY it took so long but the answer is B :)

Explanation:

Trust me and good luck :)

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

Aristarchus of Samos was just a Greek astronomer that suggested the very first heliocentric model of the cosmos, wherein the sun, rather than the earth, was even at its center. Despite the fact that his hypothesis was acknowledged by other philosophers of the time, it was dismissed as unrealistic, and the geocentric model remained in use for the next 1,700 years.

Copernicus was also the first to assert that the Earth as well as the other planets orbit the sun. It was really a significant shift in thinking.

Sun can be considered as a star in solar system.

The theory that the planets move around the sun was endorsed by Aristarchus, Copernicus, as well as Galileo. The solar system revolves around the sun.

Therefore, the correct answer will be option (b).

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Answer:

carbonated water

remaining are single element

Answer:

Structurally, plant and animal cells are very similar because they are both eukaryotic cells. They both contain membrane-bound organelles such as the nucleus, mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, and peroxisomes. Both also contain similar membranes, cytosol, and cytoskeletal elements.

Explanation:

I hope it's help

Answer:

True? The don't stay exactly still i dont think, but i'd say true.

Explanation:

Answer:

TRUE

Explanation:

In a solid, atoms are packed tightly together and move very slowly. In fact, they do not flow at all: they simply vibrate back and forth.

Key words vibrate, not movement.

Correct me if I'm wrong of course

Answer:

The periodic law states “When elements are arranged in order of increasing atomic number, there is a periodic repetition of their chemical and physical properties

Answer:

Hydrogen chloride (HCl) and Calcium hydroxide (CaOH). (see balanced equation below)

Explanation:

In a neutralization reaction as is the case of the question (see attachment), an acid would be neutralized by a base to form salt and water.

The most plausible reactants for the reaction given the number of moles of the product, is therefore Hydrogen chloride (HCl) and Calcium hydroxide (Ca(OH)2).

[tex]HCl _{(aq)} + Ca(OH)_{2} _{(aq)}[/tex] →[tex]CaCl_{2}_{(s)} + H_{2} O_{(l)}[/tex]

Let me know if this was helpful.

Answer:

Two vectors are equal if they have the same magnitude and the same direction. Just like scalars which can have positive or negative values, vectors can also be positive or negative. A negative vector is a vector which points in the direction opposite to the reference positive direction.

Answer:

[tex]6K _{(s)} + N _{2(g)} = = > \:2K _{3} N _{(s)} [/tex]

Potassium nitride

Answer:

Vav=d/t

Explanation:

Because the question already gave d=90m and t=20s. Because the car is the thing that can not travel the same distances at the same times.So the equation is V[tex]\\_{av}[/tex]=[tex]\frac{d}{t} \\[/tex]

Answer:

None have backbones

No cell walls

Multicellular

Includes radial or bilateral body symmetry.

Explanation:

Answer:

A. p → ~q

Explanation:

I am double checking.

Answer:

Fluorine

Explanation:

These particles stick in the atoms and make them radioactive.

Answer:

NO I DON'T ✌✌✌✌✌✌✌✌✌

Answer: The mole fraction of chloroform in this solution is 0.41

Explanation:

To calculate the moles, we use the equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}[/tex]

a) moles of [tex]CHCl_3[/tex]

[tex]\text{Number of moles}=\frac{49g}{119g/mol}=0.41moles[/tex]

b) moles of [tex]CH_3COBr[/tex]

[tex]\text{Number of moles}=\frac{73g}{123g/mol}=0.59moles[/tex]

To calculate the mole fraction, we use the formula:

[tex]\text{Mole fraction of a component}=\frac{\text{Moles of the component}}{\text{total moles}}[/tex]

[tex]\text{Mole fraction of chloroform}=\frac{\text{Moles of chloroform}}{\text{total moles}}=\frac{0.41}{0.41+0.59}=0.41[/tex]

The mole fraction of chloroform in this solution is 0.41

Answer:

m=621.54g

Explanation:

number of moles= mass of H2O/molar mass of H2O

n=m/mm

make mass the subject of the formula

m=n*mm

find molar mass of water

H2O=1(16)+2(1)

mm= 18.0g/mol. n=34.53mol

hence, m=34.53mol*18.0g/mol

m=621.54g

Answer:

6200 meters

Explanation:

To convert from km to m you have to multiply the number by a thousand

Answer:

6.2×10^3 m

Explanation:

6.20×1000=6200m

In scientific notation 6200 = 6.2×10^3

Answer:

each planet has a different force of gravity

Explanation:

Weight = mass× gravity

As gravity changes from place to place and also from planet to planet so weight changes.

Answer:

[tex]4.86\times10^{-7}\ \text{m}[/tex]

Explanation:

R = Rydberg constant = [tex]1.09677583\times 10^7\ \text{m}^{-1}[/tex]

[tex]n_1[/tex] = Principal quantum number of an energy level = 2

[tex]n_2[/tex] = Principal quantum number of an energy level for the atomic electron transition = 4

Wavelength is given by the Rydberg formula

[tex]\lambda^{-1}=R\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)\\\Rightarrow \lambda^{-1}=1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\\\Rightarrow \lambda=\left(1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\right)^{-1}\\\Rightarrow \lambda=4.86\times10^{-7}\ \text{m}[/tex]

The wavelength of the light emitted is [tex]4.86\times10^{-7}\ \text{m}[/tex].

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

number of atoms/molecules=number of moles × 6.022×10²³(Avogadro number)

number of moles =1.500 mole

substituting all the given values in the above equation, we get

number of atoms/molecules=1.500  × 6.022×10²³(Avogadro number)

number of atoms/molecules =9.033×10²³molecules

Therefore, 9.033×10²³ is the number of molecules in 1.500 mole of H[tex]_2[/tex]O.

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Answer:

Electronegativity is probably the biggest thing that plays into reactivity. Therefore, since fluorine has a higher electronegativity than chlorine, fluorine is more reactive.

Explanation:

I got it right

Answer:

mass of HNO₃ = 0.378 g

Explanation:

Normality = Molarity * number of equivalents

Molarity = Normality/number of equivalents

normality of HNO₃ = 0.30 N, Volume = 20 mL

HNO₃ ionizes in the following way:

HNO₃(aq) ----> H⁺ + NO₃⁻

Therefore, number of equivalents for HNO₃ is 1

molarity of HNO₃ = 0.30/1 =0.30 mol/dm³

Using the formula, molarity = number of moles/volume in liters

number of moles = molarity * volume

Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL

number of moles = 0.006 moles

From the formula, mass = number of moles * molar mass

molar mass of HNO₃ = 63.0 g/mol

mass = 0.006 * 63

mass of HNO₃ = 0.378 g

rgrgtff

ghhbbbhhghghgghgggferer

Answer:

It's false

Explanation:

Mixtures are always combinations of the same compounds that are at different states.

Answer:

50%

Explanation:

Let assume that there are:

"a" moles of CH4 & "b" moles of C2H2

Then by applying the ideal gas equation:

PV = nRT

[tex]16.8 \times 10^3 \times V = (a+b)RT[/tex]

Make (a+b) the subject of the formula:

[tex](a+b) = \dfrac{16800 \ V }{RT} mol[/tex] --- (1)

Since 1 mole of CH₄ yields 1 mol of CO₂ & 1 mol of C₂H₂ yields 2 moles of CO₂

Then;

the total moles of CO₂ = (a +2b)

Now:

[tex]25.3 \times 10^3 \times V = (a+ 2b)RT[/tex]

[tex](a + 2b) = \dfrac{25200 \ V}{RT \ mol}[/tex]    ---- (2)

∴

By solving the above equations

[tex]a = \dfrac{8400 \ V}{RT} \\ \\ b = \dfrac{8400 \ V}{RT}[/tex]

Hence, the estimate of the percentage of methane in the original mixture is:

[tex]= 100 \times \dfrac{a}{(a+b)}[/tex]

[tex]= 100 \times \dfrac{8400\dfrac{ \ V}{RT} }{8400\dfrac{ \ V}{RT} + 8400\dfrac{ \ V}{RT}}[/tex]

= 50%