Which of the following is a reasonable ground-state electron configuration?

What is the mole fraction of oxygen in a gaseous mixture containing 25 grams of oxygen, 15 grams of nitrogen, and 10 grams of he

4vir4ik [10]

Convert all the gases from grams to moles using their molar masses first. Remember that nitrogen and oxygen exist as DIATOMIC gases.

O2 - 25 g / 32 g/mol = 0.78 mol O2
N2 - 15 g / 28.02 g/mol = 0.54 mol N2
He - 10 g / 4.0 g/mol = 2.5 mol He

Add all the moles of gases.

0.78 + 0.54 + 2.5 = 3.82 moles

Divide O2 moles by total moles.

0.78/3.82 = 0.20

7 0

3 years ago

If air has a dry-bulb temperature of 2°C

Allisa [31]

Answer:

The relative humidity is 36%.

Explanation:

Relative humidity is the measure of ratio of actual vapor density to saturated vapor density in a given system. So there are different ways to measure the relative humidity in the atmosphere. One of the common ways is to measure using Psychrometer. In this instrument, two different thermometers are used as measuring device. One of the thermometer measures the humidity in dry air and another in wet air. So the difference of the temperature of dry and wet air bulb will be related to determine the relative humidity percentage. The formula to determine the relative humidity using this method is as below.

$Relative humidity=\frac{(e_{w}-[N*(1+0.00115*T_{w}*(T_{d}-T_{w}))])*100}{e_{d} }$

Also,

$e_{d}=6.112*e^{[\frac{(17.502*T_{d} )}{(240.97+T_{d} )}]}$

And,

$e_{w}=6.112*e^{[\frac{(17.502*T_{w} )}{(240.97+T_{w} )}]}$

Here e =2.718, $T_{d}$ and $T_{w}$ are the temperature at dry bulb and wet bulb temperatures, respectively.

So, the relative humidity after substituting the values of Td = 2 C and Tw = -2 C is 36%.

6 0

3 years ago

Which statements about the operation of an automated micropipettor are true? The volume dial has already been set, do not alter

yanalaym [24]

Answer:

The correct statement is that the point of initial resistance is the level of depression that will fill the pipette with the desired volume of solution.

Explanation:

The pipette can be otherwise stored vertically or horizontally, this has nothing to do with the operation, and before the operation, the dial needs to be set. Also, the plastic pipette tip should not be ejected at all, thus, no new disposable plastic tip is required for each sample.

The correct statement is that the point of initial resistance is the level of depression that will fill the pipette with the desired volume of solution.

4 0

3 years ago

Precipitation falls in these two forms: Solid / Liquid / Gas I’ll give you 77 and read the pdf

tensa zangetsu [6.8K]

Answer:

It falls in Liquid and Solid.

Explanation:

7 0

3 years ago

Hello can someone help me please and thanksss

Svetlanka [38]

the equation of the parabola is given as $y = 1/4 (x-6)^2 +1$ . D