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3 years ago

Which statement gives a reason why scientist think that the universe began with an explosion

Chemistry

1 answer:

yaroslaw [1]3 years ago

8 0

I believe the answer is

At the moment it is the best way of explaining our scientific knowledge.

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2. List and elaborate on at least two limitations of the 24-hour recall as a

Pavlova-9 [17]

Answer:

The correct answer is - may not be typical, and participant burden.

Explanation:

The 24-hour recall is nothing but a retrospective method of diet assessment. In this method, an individual is interviewed about his or her diet consumption during the last 24 hours.

The disadvantages or limitations of this method include the inability of a single day's intake to describe the typical diet, multiple recalls to intake, cost and administration time; participant burden, have to recall to reliably estimate usual intake.

5 0

3 years ago

Which is an example of an exothermic process?

LUCKY_DIMON [66]

I think it's E. heating of water

Because exothermic process discharges heat, causing the temperature of the prompt environment to rise

Please correct me if I'm wrong!! I'd be happy to fix it!! :)

6 0

3 years ago

How many atoms are in 5 mole of water? Steps

Vladimir79 [104]

Answer: 3.01 x 10^24 atoms

Explanation:

Based on Avogadro's law:

1 mole of any substance has 6.02 x 10^23 atoms

So, 1 mole of water = 6.02 x 10^23 atoms

5 moles of water = Z atoms

To get the value of Z, cross multiply

Z x 1 mole = (6.02 x 10^23 atoms x 5 moles)

Z•mole = 30.1 x 10^23 atoms•mole

Divide both sides by 1 mole

Z•mole/1 mole = 30.1 x 10^23 atoms•mole/ 1 mole

Z = 30.1 x 10^23 atoms

[Place the value of Z in standard form]

Z = 3.01 x 10^24 atoms

Thus, there are 3.01 x 10^24 atoms in 5 mole of water

3 0

2 years ago

On January 2, 2020, Nash Company purchases a call option for $290 on Merchant common stock. The call option gives Nash the optio

notka56 [123]

Answer:

Explanation:

I have the same question

5 0

3 years ago

Gaseous methane (CH4) reacts with gaseous oxygen gas (02) to produce gaseous carbon dioxide (CO2) and gaseous water (H20). What

Mariana [72]

Answer:

Theoretical yield = 3.51 g

Explanation:

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

For $CH_4$ :-

Mass of $CH_4$ = 1.28 g

Molar mass of $CH_4$ = 16.04 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{1.28\ g}{16.04\ g/mol}$

$Moles_{CH_4}= 0.0798\ mol$

For $O_2$ :-

Mass of $O_2$ = 10.1 g

Molar mass of $O_2$ = 31.998 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{10.1\ g}{31.998\ g/mol}$

$Moles_{O_2}= 0.3156\ mol$

According to the given reaction:

$CH_4+2O_2\rightarrow CO_2+2H_2O$

1 mole of methane gas reacts with 2 moles of oxygen gas

0.0798 mole of methane gas reacts with 2*0.0798 moles of oxygen gas

Moles of oxygen gas = 0.1596 moles

Available moles of oxygen gas = 0.3156 moles

Limiting reagent is the one which is present in small amount. Thus, $CH_4$ is limiting reagent.

The formation of the product is governed by the limiting reagent. So,

1 mole of methane gas on reaction produces 1 mole of carbon dioxide.

0.0798 mole of methane gas on reaction produces 0.0798 mole of carbon dioxide.

Mole of carbon dioxide = 0.0798 mole

Molar mass of carbon dioxide = 44.01 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$0.0798\ moles= \frac{Mass}{44.01\ g/mol}$

Mass of $CO_2$ = 3.51 g

Theoretical yield = 3.51 g

3 0

3 years ago