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3 years ago

When a material changes state, what happens to the bonds between the molecules?

Chemistry

1 answer:

brilliants [131]3 years ago

6 0

Answer:

When a substance is cooled it's internal energy decreases the movement of its partical decreases the bonds between particles form when a substance condenses or freezes or sublimes to form a solid from a gas 

may be this might help u

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How do you convert 34.6 kilograms to micrograms? Also the Steps that got you that answer

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40.28 sorry if it is wrong:) but I tried

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4 years ago

What effect does an ocean have on the climate

miv72 [106K]

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3 years ago

Ionic bonding gcse

cupoosta [38]

Group I and Group II have the same number of outermost electrons as you go down each group but the shells increase therefore as you go downward it becomes much easier to remove electrons because of its wide radius however group 7 and 6 have seven and six electrons in their outermost shell respectively. Therefore down the group it is much easier to attract electrons and across the period it is much harder because the number of electrons on the outermost shell increase

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3 years ago

Draw the Lewis structures for CH3OH, CH2O and HCOOH. Indicate the hybrid orbital used in the sigma bonds for each of the carbon

sdas [7]

Answer:

See figure 1

Explanation:

For this question, we have to remember that in the lewis structures all atoms must have 8 electrons. And each atom would have a different value of valence electrons:

Carbon => 4

Oxygen=> 6

Hydrogen=> 1

Additionally, for the hybridizations we have to remember that:

$Sp^3$ => 4 single bonds

$Sp^2$ => 1 double bond

$Sp^1$ => 1 double bond

With this in mind, the formaldehyde and formic acid would have $Sp^2$ carbons and the ethanol an $Sp^3$ carbon.

Finally, for the oxidation state. We have to remember that if we have more bonds with oxygen, we will have more oxidation. Therefore, the carbon that has more oxidation is the one in the formic acid (we have several bonds with oxygen).

See figure 1

I hope it helps!

4 0

3 years ago

What volume of air is needed to burn an entire 55-L (approximately 15-gal) tank of gasoline? Assume that the gasoline is pure oc

White raven [17]

Answer:

The volume of air required is 527,686.25L.

Explanation:

When the question says "burn", it refers to a combustion reaction, where a substance (in this case octane) reacts with oxygen to produce carbon dioxide and water.

Step 1: Write a balanced equation

Considering it is a combustion reaction, the balanced equation is:

C₈H₁₈ + 12.5 O₂ ⇄ 8 CO₂ + 9 H₂O

In this step, we start balancing elements that are present only in one compound on each side of the equation, namely, carbon and hydrogen.

To finish, it is important to count that there are the same number of atoms on both sides of the equation. In this case there are 8 atoms of Carbon, 18 atoms of Hydrogen and 25 atoms of Oxygen, so it is balanced.

Step 2: Find out the mass of C₈H₁₈

Since the balanced equation gives us information about the mass of C₈H₁₈ involved in the reaction, we need to find out how many grams we have.

The info we have is:

55 L of gasoline (assuming gasoline to be pure octane).
The density of octane is 0,70 g/cm³

Density relates mass and volume, so we can find out how many grams are represented by 55 L. Since the units used are different, first we need to convert liters into cm³. We use the conversión factor 1 L = 1000 cm³.

$55L.\frac{1000cm^{3} }{1L} =55000cm^{3}$

Since density = mass/volume, we can solve for mass:

$mass = density.volume=0.70\frac{g}{cm^{3} } .55,000cm^{3} =38,500g$

Step 3: Establish the theoretical relationship between the mass of octane and the moles of oxygen.

This relationship comes from the balanced equation.

For octane:

molar mass of C₈H₁₈ = molar mass of C . 8 + molar mass of H . 18 =

12 g/mol . 8 + 1g/mol . 18 = 114 g/mol

According to the balanced equation reacts 1 mol of octane, which means 114 grams of it.

For oxygen:

According to the balanced equation, 12.5 moles of oxygen react.

Then, the relationship is 114 g octane : 12.5 moles of oxygen

Step 4: Use the theorethical relationship to find the moles of oxygen that reacted

We use the mass of octane found in step 2 and apply the proper conversión factor.

$38,500g (octane) . \frac{12.5mol (oxygen)}{114g (octane)} = 4,221.49mol(oxygen)$

Step 5: Find out the volume of oxygen.

We know that 1 mol of any gas at room temperature occupies about 25 L. Then,

$4,221.49mol(oxygen).\frac{25L(oxygen)}{1mol(oxygen)} =105,537.25 L (oxygen)$

Step 6: Look the volume of air that contains such amount of oxygen

Given oxygen represents 20% of air, we can use that relationship to find the volume of air.

$105,537.25L(oxygen).\frac{100L(air)}{20L(oxygen)} =527,686.25L (air)$

4 0

4 years ago