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3 years ago

What do the coefficients located before certain molecules in each chemical equation represent?

1 answer:

6 0

It represents the number of moles required of that molecule to balance the chemical equation, which means to have the reaction chemically happen and goes to completion.

For example:
CH4 + O2 --> H2O + CO2 that is not balanced

with the coefficients located
CH4 + 2O2 --> 2H2O + CO2 now with the coefficients the number of oxygen and hydrogen on each side are equal

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9.86 x 10²⁸ O-atoms require what volume (L) N₂O₂ at STP?

jolli1 [7]

First, we use avogadro's number to convert atoms into moles. Then, relate the number of moles from elemental to the compound. Lastly, we use conditions at STP to calculate the volume. We do as follows:

9.86 x 10²⁸ O-atoms ( 1 mol / 6.022x10^23 atoms O) ( 1 mol N2O2 / 2 mol O ) ( 22.4 L / 1 mol ) = 1833809.37 L needed

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2 years ago

Animation shows a complete revolution of the Earth around the sun. What happens during this time? The moon makes one complete ph

docker41 [41]

Answer:

Four seasons occur on Earth

Explanation:

When the Earth has completely one revolution around the Sun, then it has completed 1 year, and four seasons have occurred in the meantime.

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2 years ago

The vapor pressure of water at 25.0°C is 23.8 torr. Determine the mass of glucose (molar mass = 180 g/mol) needed to add to 500.

mrs_skeptik [129]

According to Raoult's law the relative lowering of vapour pressure of a solution made by dissolving non volatile solute is equal to the mole fraction of the non volatile solute dissolved.

the relative lowering of vapour pressure is the ratio of lowering of vapour pressure and vapour pressure of pure solvent

$\frac{p^{0-}p}{p^{0}}=x_{B}$

Where

xB = mole fraction of solute=?

$p^{0}=23.8torr$

p = 22.8 torr

$x_{B}=\frac{23.8-22.8}{23.8}=0.042$

mole fraction is ratio of moles of solute and total moles of solute and solvent

moles of solvent = mass / molar mass = 500 /18 = 27.78 moles

putting the values

$molefraction=\frac{molessolute}{molesolute+molessolvent}$

$0.042=\frac{molessolute}{27.78+molessolute}$

$1.167+0.042(molesolute)=molessolute$

$molessolute=1.218$

mass of glucose = moles X molar mass = 1.218 X 180 = 219.24 grams

3 0

3 years ago

You filled out the medical questionnaire and gave it to your new doctor. The doctor reviews the form and then discusses a course

geniusboy [140]

Looking at the information given above, you will notice that, for cancer disease, the patient was sure that his parents and aunts did not have the disease condition but it does not know whether his grand parents and uncles have it or not. Therefore, he will have to find out more about history of cancer in the family.

For heart disease condition, his parents and uncles have heart problems. Because of this, the patient has to undergo preventative care for heart disease.

For diabetes condition, his grand parents have diabetes and he also thinks that his aunts have. Due to this fact, the patient also have to receive preventative care for diabetes.

8 0

3 years ago

Read 2 more answers

Calculate the osmotic pressure of 20 m solution of LiCl at 25C

Soloha48 [4]

Answer:

979 atm

Explanation:

To calculate the osmotic pressure, you need to use the following equation:

π = i MRT

In this equation,

-----> π = osmotic pressure (atm)

-----> i = van't Hoff's factor (number of dissolved ions)

-----> M = Molarity (M)

-----> R = Ideal Gas constant (0.08206 L*atm/mol*K)

-----> T = temperature (K)

When LiCl dissolves, it dissociates into two ions (Li⁺ and Cl⁻). Therefore, van't Hoff's factor is 2. Before plugging the given values into the equation, you need to convert Celsius to Kelvin.

i = 2 R = 0.08206 L*atm/mol*K

M = 20 M T = 25°C + 273.15 = 298.15 K

π = i MRT

π = (2)(20 M)(0.08206 L*atm/mol*K)(298.15 K)

π = 979 atm

5 0

2 years ago