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3 years ago

PLEASE HELP I REALLY NEED THIS IM LATE

Chemistry

1 answer:

ANTONII [103]3 years ago

4 0

Answer:

Pitch:it refers to the highest and lowness of a sound.

Wavelength: It is the distance measured from one crest to another, or from one trough to another.

Refraction of Light: The light bends as it travels from one medium to another.

Reflection of Light: It happens when light bounces back after hitting a well-polished surface.

Crest: The highest point of the wave from the center.

<u>I hope this helps! :)</u>

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I know how to solve it with D=M/V and M1V1 however the answer isn’t correct. Help me please

lara31 [8.8K]

Answer:

23.28 g of O2.

Explanation:

We'll begin by calculating the mass of hexane. This can obtain as follow:

Volume of hexane = 10 mL

Density of hexane = 0.66 g/mL

Mass of hexane =?

Density = mass /volume

0.66 = mass of hexane /10

Cross multiply

Mass of hexane = 0.66 x 10

Mass of hexane = 6.6 g

Next, we shall write the balanced equation for the reaction. This is given below:

2C6H14 + 19O2 —> 12CO2 + 14H2O

Next, we shall determine the masses of C6H14 and O2 that reacted from the balanced equation. This can be obtained as follow:

Molar mass of C6H14 = (12.01x6) + (1.008 x 14)

= 72.06 + 14.112

= 86.172 g/mol

Mass of C6H14 from the balanced equation = 2 x 86.172 = 172.344 g

Molar mass of O2 = 16x2 = 32 g/mol

Mass of O2 from the balanced equation = 19 x 32 = 608 g

From the balanced equation above,

172.344 g of C6H14 reacted with 608 g of O2.

Finally, we shall determine the mass of O2 needed to react with 10 mL (i.e 6.6 g) of hexane, C6H14. This can be obtained as follow:

From the balanced equation above,

172.344 g of C6H14 reacted with 608 g of O2.

Therefore, 6.6 g of C6H14 will react with = (6.6 x 608)/172.344 = 23.28 g of O2.

Therefore, 23.28 g of O2 is needed for the reaction.

8 0

3 years ago

All elements have a AHf, of ___

stellarik [79]

All elements have a AHf, of <u>0</u>

kJ/mole at standard temperature and pressure.

<h3>What is an element?</h3>

An element can be defined as a substance which cannot be split into two or more simpler forms by an ordinary chemical process

Below are the list of the first twenty elements:

Hydrogen
Helium
Lithium
Berylium
Boron
Carbon
Nitrogen
Oxygen
Fluorine
Neon
Sodium
Magnesium
Aluminum
Silicon
Phosphorus
Sulphur
Chlorine
Argon
Potassium
Calcium

So therefore, all elements have a AHf, of <u>0</u>

kJ/mole at standard temperature and pressure.

Learn more about elements:

brainly.com/question/11829854

#SPJ1

7 0

2 years ago

A double replacement reaction can be best described as a reaction in which

ExtremeBDS [4]

<h3>Answer </h3>

Option C= ions are exchanged between two compounds.

<h3>Explanation </h3>

A double displacement reaction, also known as a double replacement reaction or metathesis, is a type of chemical reaction where two compounds react, and the positive ions (cation) and the negative ions (anion) of the two reactants switch places, forming two new compounds or products. For example,

Na2S + 2HCl → H2S + 2NaCl

Option D is incorrect because electrons are exchanged between the atoms in oxidation –reduction reactions.

3 0

4 years ago

How many molecules are in 165 g of carbon dioxide?

devlian [24]

The molar mass of CO2 is 44 grams per mole.

165 grams / 44 grams per mole of CO2 = 3.75 moles CO2

Using Avogadro’s law where 1 mole of substance equals 6.023 x 10^23 molecules

3.75 moles CO2 (6.023 x 10^23 molecules /mole) = 2.26 x 10^24 molecules CO2

3 0

3 years ago

Read 2 more answers

Write a balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air.

Lelechka [254]

Answer: The balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is $CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O$ .

Explanation:

When a substance tends to gain oxygen atom in a chemical reaction and loses hydrogen atom then it is called oxidation reaction.

For example, chemical equation for oxidation of methane is as follows.

$CH_{4} + O_{2} \rightarrow CO_{2} + H_{2}O$

Number of atoms present on reactant side are as follows.

C = 1
H = 4
O = 2

Number of atoms present on product side are as follows.

C = 1
H = 2
O = 3

To balance this equation, multiply $O_{2}$ by 2 on reactant side. Also, multiply $H_{2}O$ by 2 on product side. Hence, the equation can be rewritten as follows.

$CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O$

Now, the number of atoms present on reactant side are as follows.

C = 1
H = 4
O = 4

Number of atoms present on product side are as follows.

C = 1
H = 4
O = 4

Since, the atoms present on both reactant and product side are equal. Therefore, this equation is now balanced.

Thus, we can conclude that balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is $CH_{4} + 2O_{2} \rightarrow CO_{2} + 2H_{2}O$ .

4 0

3 years ago