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if 0.0203 g of a gas dissolves in 1.39 l of water at 1.02 atmospheres at what pressure (in atm) would you be able to dissolve 0.

Sergeu [11.5K]

First, we need to get n1 (no.of moles of water ): when

mass of water = 0.0203 g and the volume = 1.39 L

∴ n1 = mass / molar mass of water

= 0.0203g / 18 g/mol
= 0.00113 moles

then we need to get n2 (no of moles of water) after the mass has changed:

when the mass of water = 0.146 g

n2 = mass / molar mass

= 0.146g / 18 g/ mol
= 0.008 moles

so by using the ideal gas formula and when the volume is not changed:

So, P1/n1 = P2/n2

when we have P1 = 1.02 atm

and n1= 0.00113 moles

and n2 = 0.008 moles

so we solve for P2 and get the pressure

∴P2 = P1*n2 / n1

=1.02 atm *0.008 moles / 0.00113 moles

= 7.22 atm

∴the new pressure will be 7.22 atm

5 0

3 years ago

(C6H6) can be biodegraded by microorganism. if 30 mg of benzene is present, what amount of oxygen required for biodegradation, n

quester [9]

Answer:

36.92 mg of oxygen required for bio-degradation.

Explanation:

$5C_6H_6+15O_2\rightarrow 12CO_2+15H_2O$

Mass of benzene = 30 mg = 0.03 g (1000 mg = 1 g )

Moles benzene = $\frac{0.03 g}{78 g/mol}=0.0003846 mol$

According to reaction 5 moles of benzene reacts with 15 moles of oxygen gas.

Then 0.0003846 mol of benzene will react with:

$\frac{15}{5}\times 0.0003846 mol=0.0011538 mol$ of oxygen gas

Mass of 0.0011538 moles of oxygen gas:

0.0011538 mol × 32 g/mol = 0.03692 g = 36.92 mg

36.92 mg of oxygen required for bio-degradation.

4 0

3 years ago

What is the purpose of adding phenolphthalein to your Erlenmeyer flask prior to starting a titration?

koban [17]

Answer:

a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.

Explanation:

Phenolphthalein is an organic substance with chemical formula $C_{20}H_{14}O_{4}$ .

It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.

In this way it helps visually to notice when the final point of the titration has been reached.

3 0

3 years ago

The mole fraction of a non-electrolyte (MM 40.0 g/mol) in a saturated aqueous solution is 0.310. What is the molality of the sol

jeka57 [31]

<u>Answer:</u> The molality of non-electrolyte is 24.69 m

<u>Explanation:</u>

We are given:

Mole fraction of saturated aqueous solution = 0.310

This means that 0.310 moles of non-electrolyte is present.

Moles of water (solvent) = 1 - 0.310 = 0.690 moles

To calculate the mass from given number of moles, we use the equation: