Measurements show that unknown compound X has the following composition:
element mass %
carbon 74.8%
hydrogen 25.1%
Write the empirical chemical formula of X. please help

Answers

Answer 1
X is carbon and Jess
Answer 2

the empirical chemical formula of X is CH4

Explanation:Step 1: Imagine you have a sample of compound weighing exactly . Multiply the mass of this sample by the mass percents to find the mass of each element in the sample

Step 2: Divide the mass of each element by the element's molar mass to find the moles of each element in the sample. Remember to round your answers to the correct number of significant digits.  

Step 3: Divide the moles of each element by the the smallest number of moles of any element to find the mole ratio of elements in the sample.  

Step 4: Multiply the mole ratio by the smallest whole number that changes it into a whole number ratio to find the atom ratio of elements in the sample.

Note that the result of each multiplication must equal a whole number only within measurement uncertainty.  

The measurement uncertainty in this calculation comes from the measurement uncertainty of the mass percents given in the question. The mass percents each have significant digits. That means each mass percent has some measurement uncertainty in the third significant digit, and only the first two significant digits can be considered completely reliable.  

In Step 1 you multiplied each mass percent by something with zero uncertainty (the exactly you assumed your sample weighed), in Step 2 you divided by a measurement with more than significant digits (the molar mass of the elements), and in Step 3 you divided by a measurement with the same number of significant digits (the least number of moles of any element in the compound). None of these steps added to the measurement uncertainty of your calculation.  

Therefore, the measurement uncertainty in the final result of all your calculations is determined by the measurement uncertainty in the original mass percents and will be in the third significant digit. That means the result of each of the final multiplication steps must equal a whole number only to within the first two significant digits.  

The whole numbers in the last column of the table are and .  


Related Questions

How many kilograms of water must be added to 6.07 grams of oxalic acid (H2C2O4) to make a 0.025 m solution?

Answers

This dilution problem uses the equation
M
a
V
a
=
M
b
V
b

M
a
= 6.77M - the initial molarity (concentration)
V
a
= 15.00 mL - the initial volume
M
b
= 1.50 M - the desired molarity (concentration)
V
b
= (15.00 + x mL) - the volume of the desired solution
(6.77 M) (15.00 mL) = (1.50 M)(15.00 mL + x )
101.55 M mL= 22.5 M mL + 1.50x M
101.55 M mL - 22.5 M mL = 1.50x M
79.05 M mL = 1.50 M
79.05 M mL / 1.50 M = x
52.7 mL = x
59.7 mL needs to be added to the original 15.00 mL solution in order to dilute it from 6.77 M to 1.50 M.
I hope this was helpful.

the symbol between two reactants in a chemical equation?

Answers

It’s an addition sign since two things reacting means to add them up (mix them together)

Hope this helps!!

A horse weighs 240 kg. If its running at a speed of 18 m/s, what's the linear momentum of the horse

Answers

Answer: The answer is 4320

Explanation:

I got the answer correct

Which element would you predict to have the highest first ionization energy? Why?

a) neon or carbon

b) fluorine or francium

c) beryllium or strontium

d) iodine or fluorine

Answers

the answer is c and i don’t know why

Find the volume of 2.40 moles of gas whose temperature is 50.0°C and whose pressure is 2.00 atm.

Answers

PV=nRT
n=2.4 moles
T=273.15+50=323.15K
P=2*101325=202650 Pa
R=8.31


Solve for V:
V=nRT/P=2.4*8.31*323.15/202650=.032m^3

What is the pH of a 2.0 × 10-4 M HCl solution?

Answers

Answer:

pH = 3.69

Explanation:

HCl is a strong acid. It will disscociates completely into dissoluted ions such that,

[tex][H^+]=2\times 10^{-4}\ M[/tex]

The formula for pH is given by :

[tex]pH=-log[H^+]\\\\pH=-log(2\times 10^{-4})\\\\pH=3.69[/tex]

So, the pH of the solution is 3.69.

The answer to your question is 4.

Two students pull a box with force of 100 N to the left and 200 N to the right.

What is the net force and direction in which the box moved?

Answers

Answer:

net force is 100 N and direction is right

Explanation:

How many grams are in 8.50 e 23 formula units of NaCl?
a)82.5 g
b)8.25 g
c)85.0 g
d)91.5 g

Answers

Answer:

a)82.5 g

Explanation:

To solve this problem we will use Avogadro's number, which states the number of formula units per mole.

8.50x10²³formula units ÷ 6.023x10²³ formula units/mol = 1.41 mol

Then we convert 1.41 moles of NaCl to grams, using its molar mass:

1.41 mol NaCl * 58.44 g/mol = 82.4 g

The closest answer is option a).

Hi! I need some help with this pleaseeee!!

When two objects of different temperatures are placed in contact with one another, eventually: (choose one option from below)

a) both their average kinetic energy and temperature will be the same

b) their average kinetic energy will be the same

c) neither their average kinetic energy and temperature will be the same

d) their temperature will be the same

Answers

a) eventually they will be in thermal equilibrium

Calculate the percent composition of oxygen in silicon dioxide.​

Answers

Answer:

then it is 5

Explanation:

because i said it is

please help me lol
How many grams of magnesium sulfate (MgSO4) are dissolved in 0.965 L of a 0.0575 M solution? Molar Mass Mg: 24.30 g/mol Molar Mass S: 32.06 g/mol Molar Mass O: 16.00 g/mol​

Answers

Answer:

in 4 liters of solution

MgSO4) are dissolved in 0.965 L of a 0.0575 M solution? Molar Mass Mg: 24.30 g/mol Molar Mass S: 32.06 g/mol Molar Mass O: 16.00 g/

Answer:

6.68

Explanation:

i did it and got it right

Can someone help me Balance chemical equations please

Answers

2NaClO3 = 2NaCl + 3O2
Hopes this helps <33

If 3.22 g of precipitate are recovered from the reaction of limewater (Ca(OH),) with carbon dioxide to produce
water and calcium carbonate, what is the percent yield if 20.0 g of carbon dioxide was mixed with the
limewater?
the correct answer is 7.1% but i don't understand what they did

Answers

Answer:

Percent yield = 7.1%

Explanation:

The general reaction of the problem is:

Ca(OH)₂ + CO₂ → H₂O + CaCO₃

To solve this question we need to find theoretical yield using the amount of carbon dioxide added because:

Percent yield = Actual yield (3.22g) / Theoretical yield * 100

Theoretical yield is the maximum amount of product that could be obtained. To find it we need to convert the mass of CO₂ to moles. The moles of CO₂ = Moles of CaCO₃:

Moles CO₂ -Molar mass: 44.01g/mol):

20.0g * (1mol / 44.01g) = 0.454 moles CO₂ = Moles of CaCO₃ produced

Mass CaCO₃ = Theoretical yield -Molar mass: 100.09g/mol-:

0.454 moles * (100.09g / mol) = 45.5g of CaCO₃ = Theoretical yield.

Replacing:

Percent yield = 3.22g / 45.5g * 100

Percent yield = 7.1%

Single-celled organisms need a microscope to be seen...
O True
O False

Answers

Answer:

True

Explanation:

Microscope is an instrument which is used to observe small objects. There are many types of microscope with a different magnitude.

What will a balloon do to a cloth if its negatively charged

Answers

Answer:

This involves negatively charged particles (electrons) jumping to positively charged objects. When you rub the balloons against the fabric they become negatively charged. They take some of the electrons from the fabric and leave them positively charged.

Explanation:

Negative charges attract to positive charges. If a balloon is not rubbed with the wool cloth, it has an equal amount of negative to positive charges, so it will attract to a rubbed balloon. When both balloons are rubbed with the wool cloth, the both receive negative charges, so they will repel each other.

blank a long narrow Stepside value that forms the deepest part of the ocean ​

Answers

Answer:

The answer is a trench

is lime flavor ionic or covalent​

Answers

Answer:Calcium carbonate (CaCO3), essentially, is an ionic compound having the bivalent calcium and carbonate ions. But the carbonate anion is a polyatomic species. The carbon atom is bonded to all the three oxygen atoms by covalent bonds - two carbon-oxygen single bonds and one carbon-oxygen double bond.

Explanation:So it's ionic hope this helps u. Btw may i have brainlist plz.

Name the type of light interaction feeling hotter in a black shirt than a white shirt
1. Reflected
2. Absorbed
3. Transmittied ​

Answers

It’s absorbed The outer layer of fabric does get hotter because the black color absorbs more heat. And that heat doesn't get transmitted to the skin because of the thick fabric. But thin black clothing transmits that heat to the skin, making a person hotter

Which of these forces does not act over a distance?
A. Friction
B. Electric
C. Magnetic
D. Gravitational

Answers

A. Friction is the answer

(Help would be greatly appreciated, chemistry is not my strong suit) How many moles of NaCl are present in a solution with a molarity of 8.59M and 125mL of a solution?
1. 1.07g
2. 62.7mol
3. 1.07mol
4. 62.7g

Answers

Molarity is a unit of concentration defined as the number of moles of solute (the substance being dissolved) per volume of solution (the solvent in which all the solute is dissolved). Mathematically, molarity is expressed as

[tex]M = \frac{\text{ mol solute}}{\text{ L solution}}[/tex].

In this question, we are given the molarity and the volume of a solution of NaCl. We can use this information to calculate the number of moles of NaCl present in the solution. Rearranging the equation to solve for moles of solute, we multiply the molarity by the volume of the solution (the units for volume must be in liters, so 125 mL is expressed as the equivalent 0.125 L):

[tex](8.59 \text{ M})(0.125 \text{ L}) = 1.07 \text{ moles of NaCl}.[/tex]

The question asks for the number of moles of NaCl in this solution, so number 3 would be correct.

A 30.0 mL aliquot of 0.0250 M HCl solution is titrated using 0.0500 M NaOH.

A) determine the volume of NaOH necessary and the pH at the equivalence point.

B) Determine the pH of the solution after 160.00 mL base is added.

Answers

Answer:

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hkgkfu

Explanation:

iyxyx yo gkxtuztizyidtiztizigxigxkhxhk. jvkgxitxoyfihciyxyixihxoyxyodyidtistusdtidti lo siento

i really need help, this is important to me, if not i get my harry styles tickets taken away and if that happens my life is over lol, i’m not saying it for sympathy i just REALLY need help

Answers

Explanation:

First Question

Group 18 elements. This is because the noble elements do not conduct electricity.

Second Question

Chewing in the mouth breaks food into small pieces

Third Question

How many atoms of each element are present in the molecule?

7 carbon atoms, 14 Hydrogen atoms and 1 oxygen atom

How many moles of I2 are in 8.23 moles of NaI ?

Answers

Answer: 4.12

Explanation:

we know that the given mol is 8.23 mol and they are 2NaI and I2 so we will write the equation like this.

8.23mol NaI x 1mol of I2 ÷ 2molNaI = 4.115≅ 4.12 mol of I2

we placed NaI at the bottom to cancel out with the 8.23 mol of NaI

Pleade help me! (If you guys unfortunately I am going to report you) Thank you

Answers

2nd option I think


Sorry if I’m wrong

What does Boyle's Law describe?

Answers

Answer: Image result for What does Boyle's Law describe?

This empirical relation, formulated by the physicist Robert Boyle in 1662, states that the pressure (p) of a given quantity of gas varies inversely with its volume (v) at constant temperature; i.e., in equation form, pv = k, a constant.

Explanation:

A rectangular poster is /4 yard wide and / yard tall. What is its area? Solve this problem any way you choose

Answers

Answer:

Area of rectangular poster = [tex]\frac{3}{16}[/tex] yard²

Explanation:

P.S - The exact question is -

Given - A rectangular poster is [tex]\frac{1}{4}[/tex] yard wide and [tex]\frac{3}{4}[/tex] yard tall.

To find - What is its area ?

Proof -

We know that ,

The area of rectangle = Length × Breadth

Here,

Given that,

Length of rectangle = [tex]\frac{3}{4}[/tex] yard

Breadth of rectangle = [tex]\frac{1}{4}[/tex] yard

∴ we get

Area of rectangular poster = [tex]\frac{3}{4}[/tex] × [tex]\frac{1}{4}[/tex]  yard²

                                          = [tex]\frac{3}{16}[/tex] yard²

⇒Area of rectangular poster = [tex]\frac{3}{16}[/tex] yard²

3. What tool do we use to measure force?

Answers

Spring Scale or a force gauge

Answer:

A force meter

What must be happening to the forces of attraction between particles when a change of state occurs?

Answers

Answer:

The particles need energy to overcome the attractions between them. As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles of gas in the liquid.

how would I solve this problem?

Answers

Answer:

D

Explanation:

The goal in this set up is to make sure all units cancel each other.

Since we need to go from grams to atoms, our final unit should be atoms.

Using method of elimination, let's see why other options are wrong.

A - Although 'g' is cancelled out, we are left with moles^2 / atoms

B - Although 'g' is cancelled out, we are left with moles^2 / atoms

C - Although 'mol' is cancelled out, we are left with g^2 / atoms

Which type of bonding forms due to electrical attractions between oppositely charged elements

Answers

Answer:

Explanation:

Ionic bond

Ionic bond, also called electrovalent bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.

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