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3 years ago

(Please answer asap/right now. :( )

Chemistry

1 answer:

Ganezh [65]3 years ago

8 0

Answer:

A. substance Y will float on top of substance X.

Explanation:

If an objet is more dense that other, the first one will sink because it weights more per militer, as you can see in the image below. In our case, Substance X is heavier than Y, that means that X will sink = Y will float.

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Write the electron configuration for a sodium cation with a charge of 1+

Dafna1 [17]

$1{s}^{2} 2 {s}^{2} 2 {p}^{6}$

or simply 2,8 it is isoelectronic with argon

4 0

3 years ago

Ethanol, C2H6O, is most often blended with gasoline - usually as a 10 percent mix - to create a fuel called gasohol. Ethanol is

weeeeeb [17]

Answer:

This means 463 grams of ethanol would provide less amount of energy

Explanation:

Step 1: Data given

Heat of combustion of ethanol = 326.7 kcal/mol

The heat of combustion of octane = 1.308*10³ kcal/mol

Mass of octane = 463 grams

Molar mass octane = 114.23 g/mol

Molar mass ethanol = 46.07 g/mol

Step 2: Calculate moles octane

Moles octane = mass octane / molar mass octane

Moles octane = 463 grams / 114.23 g/mol

Moles octane = 4.05 moles

Step 3: Calculate energy of combustion of 4.05 moles octane

Combustion of 1 mol octane gives us: 1.308 * 10³ kcal/mol

Combustion of 4.05 moles octane gives us 4.05 * 1.308 * 10³ kcal/mol = 5.30 * 10³ kcal

This means the combustion reaction of 463 grams of octane gives us 5.30 * 10³ kcal

Step 4:

Heat of combustion of ethanol = 326.7 kcal/mol

OR in words: combustion of 1 mol ethanol gives us 326.7 kcal energy

Moles ethanol = 463 grams / 46.07 g/mol

Moles ethanol = 10.05 moles

Since combustion of 1 mol ethanol gives us 326.7 kcal

10.05 moles ethanol will give us = 10.05 * 326.7 = 3283.3 kcal = 3.28 * 10³ kcal

5.30 * 10³ kcal > 3.28 * 10³ kcal

This means 463 grams of ethanol would provide less amount of energy

3 0

3 years ago

What is the concentration of 10.00 mL of HBr if it takes 16.73 mL of a 0.253 M LiOH solution to neutralize it?

Leni [432]

First. let's write the reaction formula: HBr +LiOH ----> LiBr + H₂O

let's get the moles of LiOH first

moles= Molarity x Liters

moles= 0.253 M x 0.01673 Liter= 0.00423 moles LiOH

using the balanced equation, you can see that 1 mol LiOH is equal to 1 mol HBr. so:

0.00423 mol LiOH = 0.00423 mol HBr

now let's find the concentration

molarity= mol/ Liters

0.00423 mol/ 0.01000 Liters= 0.423 M

3 0

3 years ago

Explain how the copper could be in the lake sample near the picnic area but not have been detected by this test.

Masja [62]

Answer:

May be the instrument is incorrect or may be error in it.

Explanation:

The copper have not been detected by this test because the test may be not for the detection of copper, may be it is used for identification of another minerals. If there is copper in the lake sample but can't be detected in the test so it means that the instrument which is used for detection is not the right one or having error in that instrument. Every mineral has a specific type of instrument that detect its presence, if we use incorrect instrument for the mineral then we can't detect the presence of that specific mineral.

8 0

2 years ago

what Is the number of photons in one J of red light (650 nm) greater than, equal to, or less than the number of photons in one J

valentinak56 [21]

For the same amount of energy, the number of photons in red light will be greater than the number of photons in blue light.
This is because the energy carried by a photon is inversely proportional to the wavelength of the photon. A longer wavelength means there is a lower energy in the photons and a shorter wavelength means that there is a higher energy. Therefore, in order for the photons to deliver one joule of energy, more of the red light photons will be required.

7 0

3 years ago