Matter is neither created nor destroyed in a chemical reaction

A student weighs an empty flask and stopper and finds the mass to be 55.844 g. She then adds about 5 mL of an unknown liquid and

Oduvanchick [21]

Answer :

(a) The pressure of the vapor in the flask in atm is, 0.989 atm

(b) The temperature of the vapor in the flask in Kelvin is, 372.7 K

The volume of the flask in liters is, 0.2481 L

(c) The mass of vapor present in the flask was, 0.257 g

(d) The number of moles of vapor present are 0.00802 mole.

(e) The mass of one mole of vapor is 32.0 g/mole

Explanation : Given,

Mass of empty flask and stopper = 55.844 g

Volume of liquid = 5 mL

Temperature = $99.7^oC$

Mass of flask and condensed vapor = 56.101 g

Volume of flask = 248.1 mL

Barometric pressure in the laboratory = 752 mmHg

(a) First we have to determine the pressure of the vapor in the flask in atm.

Pressure of the vapor in the flask = Barometric pressure in the laboratory = 752 mmHg

Conversion used :

$1atm=760mmHg$

or,

$1mmHg=\frac{1}{760}atm$

As, $1mmHg=\frac{1}{760}atm$

So, $752mmHg=\frac{752mmHg}{1mmHg}\times \frac{1}{760}atm=0.989atm$

Thus, the pressure of the vapor in the flask in atm is, 0.989 atm

(b) Now we have to determine the temperature of the vapor in the flask in Kelvin.

Conversion used :

$K=273+^oC$

As, $K=273+^oC$

So, $K=273+99.7=372.7$

Thus, the temperature of the vapor in the flask in Kelvin is, 372.7 K

Now we have to determine the volume of the flask in liters.

Conversion used :

1 L = 1000 mL

or,

1 mL = 0.001 L

As, 1 mL = 0.001 L

So, 248.1 mL = 248.1 × 0.001 L = 0.2481 L

Thus, the volume of the flask in liters is, 0.2481 L

(c) Now we have to determine the mass of vapor that was present in the flask.

Mass of flask and condensed vapor = 56.101 g

Mass of empty flask and stopper = 55.844 g

Mass of vapor in flask = Mass of flask and condensed vapor - Mass of empty flask and stopper

Mass of vapor in flask = 56.101 g - 55.844 g

Mass of vapor in flask = 0.257 g

Thus, the mass of vapor present in the flask was, 0.257 g

(d) Now we have to determine the number of moles of vapor present.

Using ideal gas equation:

PV = nRT

where,

P = Pressure of vapor = 0.989 atm

V = Volume of vapor = 0.2481 L

n = number of moles of vapor = ?

R = Gas constant = 0.0821 L.atm/mol.K

T = Temperature of vapor = 372.7 K

Putting values in above equation, we get:

$(0.989atm)\times 0.2481L=n\times (0.0821L.atm/mol.K)\times 372.7K\\\\n=0.00802mole$

Thus, the number of moles of vapor present are 0.00802 mole.

(e) Now we have to determine the mass of one mole of vapor.

$\text{Mass of one mole of vapor}=\frac{\text{Mass of vapor}}{\text{Moles of vapor}}$

$\text{Mass of one mole of vapor}=\frac{0.257g}{0.00802mole}=32.0g/mole$

Thus, the mass of one mole of vapor is 32.0 g/mole

8 0

3 years ago

A student observed a sample of water in three states of matter. The student should describe the liquid water as a state of matte

hodyreva [135]

Answer:

i say B

Explanation:

tell me if it is the right one

4 0

3 years ago

What is one chemical reaction that begins with petroleum as a starting material

emmasim [6.3K]

Answer:

Thermal decomposition or cracking

Explanation:

Petroleum is a mixture of hydrocarbons which are usually formed naturally. Petroleum undergo a host of chemical reactions. One of such is thermal decomposition or cracking.

Cracking is used in the petroleum industry to covert heavy fractions to more useful lighter ones.

When petroleum is subjected to high temperature and pressure, and in the presence of catalyst, the long chain type of petroleum will decompose into more useful smaller and lighter molecules.

Example is given below:

C₁₅H₃₂ → C₈H₁₈ + C₃H₆ + 2C₂H₄

6 0

3 years ago

The movement of charged particles cannot pass through an electrolyte to produce an electric current.

Rus_ich [418]

The movement of charged particles cannot pass through an electrolyte to produce an electric current.

True

False

FALSE

5 0

3 years ago

Determine the volume of atmospheric air (at 14 lb/in.^2) needed to fill your bike tires (assuming it holds 500 mL of air) to the

Fiesta28 [93]

Boyle Law says “the pressure of fixed amount of ideal gas which is at constant temperature is inversely proportional to its volume".

P = 1/V

Where, P is pressure of the ideal gas and V is volume of the ideal gas.

For two situations, this law can be added as;
P₁V₁ = P₂V₂

14 lb/in² x V₁ = 70 lb/in² x 500 mL
V₁ = 2500 mL

Hence, the needed volume of atmospheric air = 2500 mL

Here, we made two assumptions. They are,
1. The atmospheric air acts as ideal gas.
2. Temperature is a constant.

We didn't convert the units to SI units since converting volume and pressure are products of two numbers, they will cut off.

3 0

3 years ago