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3 years ago

Which of the following natural hazards occur for a long period of time?

Chemistry

1 answer:

saul85 [17]3 years ago

3 0

Answer:

drought

Explanation:

droughts are long periods without water

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A gram of gasoline produces 45 kJ of energy when burned. Gasoline has a density of 0.77 g/mL. How would you calculate the amount

BigorU [14]

The energy produced in the burning of gasoline = 45 kJ/g. So, amount of energy produced by burning 48 L gasoline = 45 kJ/g×36960 g = 1663200 kJ.

4 0

3 years ago

True or false applied chemistry does not have a specific goal or application

melisa1 [442]

Answer:

False. The goal of chemistry is to accumulate knowledge. Sometimes true. Biochemistry involves ... Sometimes true. Applied Chemistry is used to attain specific goals ... Applied Chemistry.

Explanation:

I really hope this helped :)

7 0

3 years ago

4. Arrange the following substances in order of increasing boiling point: CH3CH2OH, HOCH2CH2OH, CH3CH2Cl , and ClCH2CH2OH A. CH3

Studentka2010 [4]

Answer: Option (B) is the correct answer.

Explanation:

A molecules that will have more number of hydrogen bonding will has highest boiling point because to break the hydrogen bonds high heat needs to be provided.

So, in the molecule $HOCH_{2}CH_{2}OH$ there is presence of two alcoholic groups. Hence, it will have strongest hydrogen bonding as compared to the rest of molecules.

In the molecule $ClCH_{2}CH_{2}OH$ there will be hydrogen bonding and dipole-dipole interactions. Hence, it boiling point will be slightly less than $HOCH_{2}CH_{2}OH$ .

In the molecule $CH_{3}CH_{2}OH$ , there will be only hydrogen bonding. Hence, its boiling point is less than $ClCH_{2}CH_{2}OH$ .

In the molecule $CH_{3}CH_{2}Cl$ , there is no hydrogen bonding but there will be only dipole-dipole interactions. Hence, its boiling point will be the least.

Therefore, we can conclude that increasing order of boiling point will be as follows.

$CH_{3}CH_{2}Cl$ < $CH_{3}CH_{2}OH$ < $ClCH_{2}CH_{2}OH$ < $HOCH_{2}CH_{2}OH$

6 0

3 years ago

If 43.7 g of iron is completely used to produce 62.5 g of iron (III) oxide, how many grams of oxygen are involved in the reactio

Kobotan [32]

Mass of Oxygen : 18.8 g

<h3>Further explanation</h3>

Reaction(balanced) :

4Fe + 3O₂ → 2Fe₂O₃

mass Fe = 43.7 g

mol Fe(MW= 55,845 g/mol) :

$\tt mol=\dfrac{mass}{MW}\\\\mol=\dfrac{43.7}{55.845}\\\\mol=0.783$

mol O₂ : mol Fe = 3 : 4, so mol O₂ :

$\tt \dfrac{3}{4}\times 0.783=0.5873$

Mass O₂(MW=32 g/mol) :

$\tt mass=mol\times MW\\\\mass=0.5873\times 32\\\\mass=18.7936~g\approx 18.8$

Or simply you can Conservation of mass, where the masses before and after the reaction are the same

<em>mass reactants=mass products</em>

mass iron+mass oxygen=mass iron (III) oxide

43.7 g + mass oxygen=62.5 g

mass oxygen = 62.5 - 43.7 = 18.8 g

5 0

3 years ago

A researcher is measuring changes in the density of the upper atmosphere over time. Which units should be used for the density m

valina [46]

Answer:

lbm/ft³ or psi/ft

Explanation:

The description in the question shows the density to measured is that of gases (upper atmosphere). The density of a gas can be described as the mass of the gas divided by the volume of the gas at a certain temperature and pressure. It's unit can be represented as lbm/ft³ or psi/ft.

NOTE:

"lbm" means "lean body mass" which is a unit for mass or weight and can be described as the pound mass

"psi" means "pound per square inch"; is also a unit for mass or weight

5 0

3 years ago