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3 years ago

To make a 2.0-mole solution, how many moles of solute must be dissolved in 0.50 liters of solution?

1 answer:

3 0

There are a number of ways to express concentration of a solution. This includes molarity. Molarity is expressed as the number of moles of solute per volume of the solution. The concentration of the solution is calculated as follows:

Molarity = 2.0 mole / L solution

<span>2.0 mole / L solution ( 0.50 Liters ) = 1 mole solute</span>

<span>The correct answer is the third option. One mole of solute needed to make 0.50 liters of 2M solution.</span>

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A gas occupies a volume of 650.0 mL when the pressure is 3.50 atm. What will the new volume be if the pressure is reduced to 1.6

Gemiola [76]

The new volume will be 1379 mL.

Explanation:

As per Boyle's law, the product of initial volume and initial pressure of any gas molecule is equal to the product of final volume and final pressure of those molecules.

So here the initial volume is 650 ml and the initial pressure is 3.50 atm. As the temperature is said to be constant, then this system will be obeying Boyle's law. So, the final pressure is given as 1.65 atm. As there is a reduction in the pressure, the volume of the gas is tend to get expanded.

$P_{1} V_{1} = P_{2} V_{2}$

So, $(650*10^{-3}*3.50)=(1.65*V_{2})$

$V_{2} = \frac{650*10^{-3}*3.50}{1.65} = 1379 mL$

So, the new volume of the gas on reduction in pressure is 1379 mL.

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3 years ago

Why was Becquerel’s experiment a first step in discovering radioactivity?

galina1969 [7]

This was because the experiment showed that a substance could emit radiation even while it was not exposed to light.

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3 years ago

Read 2 more answers

How do you do part B?

galina1969 [7]

I cannot see the whole equation.Therefore I shall not answer

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3 years ago

What pressure, in atm, would be exerted by 0.023 grams of oxygen (O2) if it occupies 31.6 mL at 91

Vikentia [17]

Answer: A pressure of 0.681 atm would be exerted by 0.023 grams of oxygen $(O_2)$ if it occupies 31.6 mL at $91^{o}C$ .

Explanation:

Given : Mass of oxygen = 0.023 g

Volume = 31.6 mL

Convert mL into L as follows.

$1 mL = 0.001 L\\31.6 mL = 31.6 mL \times \frac{0.001 L}{1 mL}\\= 0.0316 L$

Temperature = $91^{o}C = (91 + 273) K = 364 K$

As molar mass of $O_2$ is 32 g/mol. Hence, the number of moles of $O_2$ are calculated as follows.

$No. of moles = \frac{mass}{molar mass}\\= \frac{0.023 g}{32 g/mol}\\= 0.00072 mol$

Using the ideal gas equation calculate the pressure exerted by given gas as follows.

PV = nRT

where,

P = pressure

V = volume

n = number of moles

R = gas constant = 0.0821 L atm/mol K

T = temperature

Substitute the value into above formula as follows.

$PV = nRT\\P \times 0.0316 L = 0.00072 mol \times 0.0821 L atm/mol K \times 364 K\\P = \frac{0.00072 mol \times 0.0821 L atm/mol K \times 364 K}{0.0316 L}\\= 0.681 atm$

Thus, we can conclude that a pressure of 0.681 atm would be exerted by 0.023 grams of oxygen $(O_2)$ if it occupies 31.6 mL at $91^{o}C$ .

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3 years ago

In your own words, explain why we have seasons on Earth. Why do some places have all 4 seasons and others seem to only have 1 or

Ber [7]

We have seasons on earth because of the way the earth is tilt on its axis. at a certain time in the year, the sun's rays reach certain parts of the globe more than others.

some places have 4 seasons because they are in the northern hemisphere, which is in the sweet spot of the sun's rays that give us each season. other places only have 1 or 2 because they are not in the northern hemisphere.

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3 years ago