Ask question

Ask question

All categories

3 years ago

6

When conducting this experiment some procedures call for heating the substance several times and recording the mass after each h

eating continuing until the mass values are constant .explain the purpose and how it might reduce error.

1 answer:

Akimi4 [234]3 years ago

8 0

Answer:

by taking your time in order to collect data

Explanation:

You might be interested in

2. Some nitrogen at a pressure of 35.75 p.s.i is in a 100 L container. If the container's volume is reduced to 2250 ml then what

elena-s [515]

Answer:

1455.6

Explanation: you first convert 2250ml to l by dividing by 1000 so you get 2.25l then you use Boyles law which is p1v1=p2v2 then insert values

35.75*100=p2*2.25 then divide both sides by 2.25 then you get 1455.6

4 0

3 years ago

A student has a 2.19 L bottle that contains a mixture of O 2 , N 2 , and CO 2 with a total pressure of 5.57 bar at 298 K . She k

Sergeeva-Olga [200]

<u>Answer:</u> The partial pressure of oxygen gas is 2.76 bar

<u>Explanation:</u>

To calculate the number of moles, we use the equation given by ideal gas which follows:

$PV=nRT$

where,

P = pressure of the gas = 5.57 bar

V = Volume of the gas = 2.19 L

T = Temperature of the gas = 298 K

R = Gas constant = $0.0831\text{ L bar }mol^{-1}K^{-1}$

n = Total number of moles = ?

Putting values in above equation, we get:

$5.57bar\times 2.19L=n\times 0.0831\text{ L. bar }mol^{-1}K^{-1}\times 298K\\\\n=\frac{5.57\times 2.19}{0.0831\times 298}=0.493mol$

To calculate the mole fraction of carbon dioxide, we use the equation given by Raoult's law, which is:

$p_{A}=p_T\times \chi_{A}$ ........(1)

where,

$p_A$ = partial pressure of carbon dioxide = 0.318 bar

$p_T$ = total pressure = 5.57 bar

$\chi_A$ = mole fraction of carbon dioxide = ?

Putting values in above equation, we get:

$0.318bar=5.57bar\times \chi_{CO_2}\\\\\chi_{CO_2}=\frac{0.381}{5.57}=0.0571$

Mole fraction of a substance is given by:

$\chi_A=\frac{n_A}{n_A+n_B}$

We are given:

Moles of nitrogen gas = 0.221 moles

Mole fraction of nitrogen gas, $\chi_{N_2}=\frac{0.221}{0.493}=0.448$

Calculating the partial pressure of oxygen gas by using equation 1, we get:

Mole fraction of oxygen gas = (1 - 0.0571 - 0.448) = 0.4949

Total pressure of the system = 5.57 bar

Putting values in equation 1, we get:

$p_{O_2}=5.57bar\times 0.4949\\\\p_{O_2}=2.76bar$

Hence, the partial pressure of oxygen gas is 2.76 bar

6 0

3 years ago

How would the moon appear from earth if the moon did not rotate?

ivolga24 [154]

If the moon did not rotate we would see all hemispheres of the moon as it revolves around the Earth and not just the phases.

4 0

3 years ago

The temperature in a town started out at 55 degrees. By the end of the day the temperature dropped to -6 degrees.

garik1379 [7]

Answer:

The choice of the answer is fourth option that is -61 degrees.

Therefore the temperature drop is -61°Centigrade.

Explanation:

Given:

The temperature in a town started out at 55 degrees

Start temperature = 55°Centigrade. (Initial temperature)

End of the Day = -6°Centigrade. (Final temperature)

To Find:

How far did the temperature drop?

Solution:

We will have,

$\textrm{Temperature drop}=\textrm{Final temperature}-\textrm{Initial temperature}$

Substituting the above values in it we get

$\textrm{Temperature drop}=-6-55\\\\\therefore \textrm{Temperature drop}=-61\° centigrade$

Therefore the temperature drop is -61°Centigrade.

4 0

3 years ago

Osmosis is the passage of water molecules through a semi-permeable membrane from a solution of ________ concentration to _______

grandymaker [24]

Osmosis is the passage of water molecules through a semi-permeable membrane from a solution of ___lower_____ concentration to ___higher_____ concentration.

3 0

3 years ago