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4 years ago

Can someone help me

Chemistry

2 answers:

Natalka [10]4 years ago

8 0

#2. 4.6 billion years

wel4 years ago

5 0

I believe # 1 is an era and # 2 4.6 billion

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Write a short paragraph on the harms caused by microorganisms

lutik1710 [3]

Answer:

Some serious diseases like anthrax is also caused in animals by the microbes. Microbes also cause diseases of plants like blights in potatoes, sugarcanes, oranges etc. They also reduce the yield. Microbes grow on food products and render them unfit for consumption.

Explanation:

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3 years ago

Which of the following substances would you predict to have the highest DHvap? Group of answer choices CH3CH2CH2CH3 CH3CH2OH HF

Katyanochek1 [597]

Answer:

a) $CH_3CH_2CH_2CH_3$

Explanation:

In this question we have the following answer choices:

a) $CH_3CH_2CH_2CH_3$

b) $CH_3CH_2OH$

c) $HF$

d) $CH_3Cl$

e) $HOCH_2CH_2OH$

We have to remember the relationship between intermolecular forces and vapor pressure. If we have stronger intermolecular forces we will have less vapor pressure because the molecules have more interactions between them, so, the molecules will prefer to stay in a liquid state rather than a gaseous state. Now, we have to check each molecule:

a) $CH_3CH_2CH_2CH_3$ (Van der waals interactions)

b) $CH_3CH_2OH$ (Hydrogen bonding)

c) $HF$ (Hydrogen bonding)

d) $CH_3Cl$ (Dipole-dipole interaction)

e) $HOCH_2CH_2OH$ (Hydrogen bonding)

For molecules b, c and e we have hydrogen bond to a heteroatom (O, N, S, or P). In this case oxygen, therefore we will have hydrogen bonding interactions (a very strong interaction). So, we can discard these ones.

In molecule e, we have "Cl" bond to a "C" therefore we will have the presence of a dipole (due to the electronegativity difference). If we have a dipole, we will have a dipole-dipole interaction (a strong interaction, less than hydrogen bonding but still is a strong interaction).

In molecule a, we have only Van der Waals interactions because in this molecule we have only carbon and hydrogen atoms bonded by single bonds. So, we will have a non-polar molecule. These interactions are the weakest interactions of all the molecules given. So, if we have weaker interactions the molecules can be converted to a gas state more easily and we have more vapor pressure. 

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3 years ago

What solutes are soluble in water?

marusya05 [52]

Answer:

Ionic compounds, such as sodium chloride, are also highly soluble in water. Because water molecules are polar, they interact with the sodium and chloride ions. In general, polar solvents dissolve polar solutes, and nonpolar solvents dissolve nonpolar solutes.

Explanation:

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4 years ago

How will you test for the gas which is liberated when hcl reacts with an active metal ?

DENIUS [597]

When HCl reacts with a metal, hydrogen gas will be evolved. To test this gas, insert a burning splinter into the outlet of gas, the flame will be extinguished with a pop sound. This will confirm the gas is hydrogen.

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3 years ago

How many total electrons can be contained in the 4d sublevel? 2 6 10 14

qaws [65]

The s sublevel has just one orbital, so can contain 2 electrons max. The p sublevel has 3 orbitals, so can contain 6 electrons max. The d sublevel has 5 orbitals, so can contain 10 electrons max. And the 4 sublevel has 7 orbitals, so can contain 14 electrons max.
So, having this in mind, 10 electrons in total can be contained in the 4d sublevel.

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4 years ago

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