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2 years ago

Hello! I need a bit of help and Im kinda in a bit of a hurry so please help! Thank you :D

Chemistry

2 answers:

Scorpion4ik [409]2 years ago

8 0

The first one is substance 3
The second one is Oxygen, Helium, and carbon dioxide
The third one is the oil floats on top of the water

aalyn [17]2 years ago

8 0

Answer:

so for the first one it is the third one the second one it is carbon dioxide and for the third one,. Gasoline is an oil product. It floats and doesn't mix with water.

Explanation:

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The mercury-201 nuclide radioactively decays by electron capture. Write a balanced nuclear chemical equation that describes this

ICE Princess25 [194]

Answer:

Explanation:

Electron capture is a form of beta decay in which the nucleus of a radionuclide captures an electron. In the case of mercury-201, the equation below illustrates that

²⁰¹₈₀Hg + ⁰₋₁e ⇒ ²⁰¹₇₉Au

As can be seen above, the electron capture reduces the atomic number by one unit leading to the production of a new radioisotope (because of the change in atomic number).

8 0

2 years ago

A laboratory analysis of an unknown sample yields 40.5% carbon, 4.5% hydrogen, and 55.0% oxygen. if the sample has a molar mass

den301095 [7]

Answer is: molecular formula is C₆H₈O₆.
n(C) = m(C) ÷ M(C).
n(C) = 40,5 g ÷ 12 g/mol.
n(C) = 3,375 mol.
n(H) = m(H) ÷ M(H).
n(H) = 4,5 g ÷ 1 g/mol.
n(H) = 4,5 mol.
n(O) = m(O) ÷ M(O).
n(O) = 55 g ÷ 16 g/mol.
n(O) = 3,4 mol.
n(C) : n(H) : n(O) = 3,375 mol : 4,5 mol : 3,4 mol / :3,375.
n(C) : n(H) : n(O) = 1 : 1,33 : 1.
n(C) : n(H) : n(O) = 3 : 4 : 3.
M(C₃H₄O₃) = 88 g/mol · 2 = 176 g/mol.

6 0

2 years ago

Calculate the specific heat of a piece of wood if 2000 g of wood absorbs 75,250 J of heat, and its temperature changes from 30°C

inna [77]

Answer:

Explanation:

The specific heat capacity=quantity of heat in joule/mass×change in temperature

from this question the quantity of heat is 75250,the mass is 2000 and the change in temperature is 50-30

which is 20

therefore

c=75250/2000×20

c=75250/40000

c=1.88

I hope this helps

3 0

3 years ago

How would you make a 2.00L of 0. 500M sodium chloride solution. (assume you have a fully equipped lab with water); sketch, calc

Gwar [14]

Answer:

Sodium chloride solution:

First you need to calculate the mass of salt needed (done in the explanation), which is 58.44g. Then it have to be weighted in an analytical balance in a weighting boat and then transferred into a 2L volumetric flask that is going to be filled until the mark with distilled water.

Sulfuric acid dilution:

First you need to calculate the volume needed (done in the explanation), it is 16.6 mL. Using a graduated pipette one measures this volume and transfer it into a 2L volumetric flask that is already half filled with distilled water, and then one fills it until its mark.

Explanation:

Sodium chloride solution:

Each liter of a 0.500M solution has half mol, so 2L of said solution has 1 mol of salt. Sodium chloride molar mass is 58.44g/mol, so in 2L of solution there is 58.44g of salt. That`s the mass that`s going to be weighted and transferred to a 2L volumetric flask.

Sulfuric acid dilution:

This is the equation for dilution of solutions:

$c_{1} v_{1} =c_{2} v_{2}$

Where "c1" stands for the initial concentration (stock solution concentration), "v1" for the initial volume (volume of stock solution used), "c2" for the desired concentration and "v2" for the desired volume.

When we are diluting from a stock solution we want to know how much do we have to pipette from the stock solution into our volumetric flask. We do so by isolating the "v1" term from the dilution equation:

$v_{1} =\frac{c_{2} v_{2} }{c_{1} }$

in this case that would be:

$v_{1} =\frac{0.100 x2.0 }{12.0 }=0.0166L=16.6mL$

5 0

2 years ago

How many solutions does the system have? zero one two three four infinitely many.

Ber [7]

Answer:

the system has infinitely many solutions.

Explanation:

The system is 2x + y = 1 and 4x + 2y = 2. Solutions to a system are the intersection points. Since these two lines are the same line they intersect everywhere. There are infinitely many solutions.

hope this helps

plz mark brainliest

4 0

2 years ago