please help me please

Answer:

[tex]\boxed {\boxed {\sf A. \ 2.48 \ mol \ Na_2O}}[/tex]

Explanation:

We are asked to convert an amount in grams to moles. To do this, we use the molar mass. This is the number of grams in one mole of a substance. It is the same value numerically as the atomic mass on the Periodic Table, however the units are grams per mole, not atomic mass units.

Look up the molar masses for the individual elements.

Look back at the formula: Na₂O. Notice there is a subscript of 2 after sodium. This means there are 2 atoms of sodium in every molecule, so we have to multiply sodium's molar mass by 2 before adding oxygen's.

Set up a ratio using the molar mass.

[tex]\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]

Multiply by the given number of grams.

[tex]154 \ g \ Na_2O*\frac {61.9785386 \ g \ Na_2O}{1 \ mol \ Na_2O}[/tex]

Flip the ratio so the grams of sodium oxide can cancel each other out.

[tex]154 \ g \ Na_2O*\frac {1 \ mol \ Na_2O}{61.9785386 \ g \ Na_2O}[/tex]

[tex]154 *\frac {1 \ mol \ Na_2O}{61.9785386 }[/tex]

[tex]\frac {154}{61.9785386 } \ mol \ Na_2O[/tex]

[tex]2.48473106141 \ mol \ Na_2O[/tex]

The original measurement of grams given has 3 significant figures, so our answer must have the same. For the number we calculated, that is the hundredth place.

The 4 in the thousandth place tells us to leave the 8.

[tex]2.48 \ mol \ Na_2O[/tex]

There are 2.48 moles of sodium oxide in 154 grams, so choice A is correct.

Answer:

χsolvent = 1.0000 - 0.1000 = 0.9000

Use Raoult's Law:

Psolution = (χsolvent) (P°solvent)

x = (0.900) (25.756)

x = 23.18 mmHg (to four sig figs)

The vapor pressure of an aqueous solution is  x = 23.18 mmHg (to four sig figs)

χsolvent = 1.0000 - 0.1000 = 0.9000

Use Raoult's Law:

P solution = (χsolvent) (P°solvent)

x = (0.900) (25.756)

x = 23.18 mmHg (to four sig figs)

An aqueous answer is one in which the solvent is liquid water. that is, solute (dissolved) ions and molecules are surrounded by water molecules and integrated into the network of bonds within the water. The dissolved species then spread in the course of the water.

A solution wherein water is the solvent is called an aqueous solution. although water is an exceptional solvent, now not the whole thing dissolves comfortably in the water.

Aqueous' in a chemical equation suggests that the cloth dispersed in water (an answer in water). As an example, when we pour sodium hydroxide answer into dilute hydrochloric acid, we get an aqueous solution of sodium chloride. The liquid is used to signify the formation of liquid materials in response.

Learn more about the aqueous solution here: https://brainly.com/question/19587902

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Answer:

The answer is "52.8".

Explanation:

Please find the graph file in the attachment.

They have the atoms in 8 corners with one unit cell in an one so mesh (SCC).

Atoms throughout the corner contribute [tex]\frac{1}{8}[/tex]to both the cell unit

Atom number per SCC unit cell, [tex]Z = (8 \times \frac{1}{8}) = 1[/tex]

Let 'r' become the atom's radius.  [tex]r = 3.43\times 10^{-8}\ \ cm[/tex]

We can see from the diagram that edge length [tex]AB = a = 2r[/tex]

[tex]Packing\ efficiency = \frac{(1 \ atom \ Volume \times Z)}{Volume \ of \ unit\ cell \times 100}\\\\[/tex]

                                 [tex]= \frac{\frac{4}{3}\times \pi \times r^3 \times 1}{a^3 \times 100}\\\\=\frac{\frac{4}{3}\times \pi \times r^3 \times 1}{(2r)^3 \times 100} \\\\=\frac{\frac{4}{3}\times \pi \times( 3.43\times 10^{-8}cm)^3 \times 1}{(2\times 3.43\times 10^{-8}cm)^3 \times 100}\\\\= 52.8 \%[/tex]

Answer:

b I hope this is right good luck

Answer:

The answer is "4.31"

Explanation:

aniline millimoles [tex]= 111 \times 0.37 = 41.07[/tex]

added [tex]HNO_3[/tex]  millimoles [tex]= 79.1 \times 0.35 = 27.685[/tex]

[tex]\to 41.07 - 27.685 = 13.385[/tex] millimoles aniline left

[tex]\to 27.685[/tex] millimoles salt formed

total volume[tex]= 111 + 79.1 = 190.1\ mL\\\\[/tex]

[tex]\to [aniline] = \frac{13.385}{190.1} = 0.07 \ M\\\\\to [salt] =\frac{ 27.685}{ 190.1} = 0.146\ M\\\\\to pOH = pKb + \frac{\log [salt]}{ [base]}\\\\\to pOH = 9.37 + \frac{\log [0.146]}{[0.07]}\\\\\to pOH = 9.69\\\\\to pH = 14 - 9.69\\\\\to pH = 4.31\\[/tex]

Answer:

P has a formal charge of 0

Explanation:

Essentially P is in the middle of that ion, and its valence electrons are being used with the 4 Os. Hope that makes sense or helps at least. There's good videos that talk about how this works but I can't link them in brainly

Answer:

See Explanation

Explanation:

The conductivity of water refers to how much it conducts electricity. The electrical conductivity of water increases as more ions are dissolved in it.

Hence, increase in concentration of dissolved ions improves the electrical conductivity of water.

Therefore, when a base (which is an ionic substance) is dissolved in water, the concentration of ions present increases and the conductivity of the solution increases accordingly since ions are charge carriers in solution.

The addition of a base to the sample results in an increase in the conductivity of the sample.

Conductivity can be defined as the transfer of charge by the sample. The sample has consisted of the ions that mediate the transfer of charge.

The sample with a high number of ions has consisted of high conductivity and vice versa. The dissolution of acid or base to the solution results in an increase in the number of ions in the solution, and thereby there has been an increase in the charge transfer.

Thus, with the increase in the charge transfer, there has been an increase in the conductivity of the sample.

For more information about the conductivity of the sample, refer to the link:

https://brainly.com/question/6072723

Answer:

Explanation:

(The MW of CuSO4 is 250 g/mol).

Answer:

5 grams of CuSO4

Explanation:

First you make a stoichiometric relationship between the molarity and liters. So there is 2 mols per every liter. Then you put in the moleculur weight( for every mol there is 250 g). Then you have to get rid of the liters, so you times the equation by 0.01(this was found by 10ml converted into liters). After all of that you should end up with 5 grams of CuSo4

Answer:

3.54 mol

Explanation:

Step 1: Given data

Step 2: Convert "T" to Kelvin

We will use the following expression.

K = °C + 273.15

K = 45.00°C + 273.15 = 318.15 K

Step 3: Calculate the number of moles (n) of argon gas

We will use the ideal gas equation.

P × V = n × R × T

n = P × V/R × T

n = 2.50 atm × 37.0 L/(0.0821 atm.L/mol.K) × 318.15 K = 3.54 mol

Answer:

Explanation:

So we know q = mc[tex]\Delta[/tex]T.

q = 55.7 J

c = 0.129j/g°C

and [tex]\Delta[/tex]T = 314-274 = 40°C.

and m is mass which can solve since we got every other variable. We will get m = 10.8g.

Answer:

A.................. I think the answer

Answer:

The correct answer is - D. Red, green, violet​.

Explanation:

Visible light is the spectrum of light that can be seen by the naked eyes of humans without any equipment. This spectrum has various frequency light that helps us see things in color. The frequency of light ranges between seven different colors in which violet has the highest frequency and red has the lowest.

The different frequencies are as follows:

color               frequency

red (limit) 1.77

red                  1.91

orange  2.06

yellow  2.14

green  2.25

cyan  2.48

blue          2.75

violet (limit) 3.10

On this basis of this the group of colors of the visible light is listed from

lowest to the highest frequency - Red, green, violet​

Answer:

pH = 6.167

Explanation:

The weak acid, HX, reacts with NaOH as follows:

HX + NaOH → NaX + H₂O

Where 1 mole of HX with 1 mole of NaOH produce 1 mole of NaX (The conjugate base of the weak acid).

Now, using H-H equation:

pH = pKa + log [NaX] / [HX]

Where pH is the pH of the buffer

pKa is -log Ka = 6.167

And [NaX] [HX] are the molar concentrations of each specie

Now, at the neutralization of the half of HX, the other half is as NaX, that means:

[NaX] = [HX]

And:

pH = pKa + log [NaX] / [HX]

pH = 6.167 + log 1

Answer:

your image is a blavk screen so we cant tell

Explanation:

Answer:

A: True

Explanation:

Statement is true because chrysanthemic acid is formed naturally as a result of production of two molecules of dimethylallyl diphosphate which forms pyrophosphate ester.

Thus, it belongs to the pyrethrum family

Answer:

hereeee

Explanation:

Limitations to population growth are either density-dependant or density-independent. Density-dependent factors include disease, competition, and predation. Density-dependant factors can have either a positive or a negative correlation to population size.

Answer: environmental factors

Explanation:

Answer:

The presence of free chlorine in drinking water is correlated with the absence of most disease-causing organisms, and thus is a measure of the potability of water

Answer:

The equilibrium constant is 2.08x10⁵

Explanation:

Based on the reaction:

3NO ⇄ N₂O + NO₂

The equilibrium constant, k, is defined as:

k = [NO₂] [N₂O] / [NO]³

Where the [] is the molarity in equilibrium of each specie.

Computing te values of the problem:

k = [1.5x10⁻¹M] [2.4x10⁻³M] / [1.2x10⁻³M]³

k = 2.08x10⁵

Answer:True

Explanation:

PLZ GIVE ME BRAINLIEST, I NEED IT

Answer:

your answer is 3 hope this helps you

Answer:

A wind farm

Explanation:

another word is a wind park

Answer:

I think it's A. I'm pretty sure.

Explanation:

Answer:

Coal, oil and natural gas are called _________A. fossil fuels

Answer:

dry ice or solid carbon(iv)oxide

Explanation:

carbon(iv)oxide that sublimes is known as dry ice or solid CO2 and it is used to refrigerate food instead of ordinary ice which will just melt when exposed to hot conditions and there4 will lead to the destruction of food. dry ice will sublime the moisture from the food there4 keeping out any moisture

Answer:

2.20 x 10²⁵ atoms

Explanation:

Atoms of CO= 36.6-mol sample

From Avogadro's constant, which is

(6.022 × 10^ 23 atoms per mole)

Then

Number of atoms=[ 6.022 × 10^ 23 atoms/mole] × [36.6-mol]

= 2.20 x 10²⁵ atoms

Hence, number of atom is 2.20 x 10²⁵ atoms

Answer:

The coefficient of Fe₂O₃ is 1

Explanation:

__Fe₂O₃ + 3H₂ —> 2Fe + 3H₂O

To know the correct coefficient of Fe₂O₃, we shall balanced the equation. This can be obtained as follow:

Fe₂O₃ + H₂ —> Fe + H₂O

There are 2 atoms of Fe on the left side and 1 atom on right side. It can be balance by writing 2 before Fe as shown below:

Fe₂O₃ + H₂ —> 2Fe + H₂O

There are 3 atoms of O on the left side and 1 atom on the right side. It can be balance by writing 3 before H₂O as shown below:

Fe₂O₃ + H₂ —> 2Fe + 3H₂O

There are 2 atoms of H on the left side and 6 atoms on the right side. It can be balance by writing 3 before H₂ as shown below:

Fe₂O₃ + 3H₂ —> 2Fe + 3H₂O

Now, the equation is balanced.

Thus, the coefficient of Fe₂O₃ is 1