All categories

3 years ago

The first method of determining the chemical composition of substances in space was to _____.

1 answer:

5 0

Answer:The first method to determine the chemical composition of a substance in space was using light. By determining red shift in the observed spectrum of light they could determine the elements they were observing

Explanation:

You might be interested in

If 20.0g of CO2 and 4.4g of CO2

Ksivusya [100]

The given question is incorrect. The correct question is as follows.

If 20.0 g of $O_{2}$ and 4.4 g of $CO_{2}$ are placed in a 5.00 L container at $21^{o}C$ , what is the pressure of this mixture of gases?

Explanation:

As we know that number of moles equal to the mass of substance divided by its molar mass.

Mathematically, No. of moles = $\frac{\text{mass}}{\text{molar mass}}$

Hence, we will calculate the moles of oxygen as follows.

No. of moles = $\frac{\text{mass}}{\text{molar mass}}$

Moles of $O_{2}$ = $\frac{20.0 g}{32 g/mol}$

= 0.625 moles

Now, moles of $CO_{2} = \frac{4.4 g}{44 g/mol}$

= 0.1 moles

Therefore, total number of moles present are as follows.

Total moles = moles of $O_{2}$ + moles of $CO_{2}$

= 0.625 + 0.1

= 0.725 moles

And, total temperature will be:

T = (21 + 273) K = 294 K

According to ideal gas equation,

PV = nRT

Now, putting the given values into the above formula as follows.

P = $\frac{nRT}{V}$

= $\frac{0.725 mol \times 0.08206 Latm/mol K \times 294 K}{5.00 L}$

= $\frac{17.491089}{5}$ atm

= 3.498 atm

or, = 3.50 atm (approx)

Therefore, we can conclude that the pressure of this mixture of gases is 3.50 atm.

4 0

3 years ago

2. How many molecules are contained in 25 L of N₂ at S. T.P.?

irina [24]

Explanation:

How many nitrogen molecules are in 1 liter of nitrogen gas at STP?

Answer

Request

Details

Ad by Amazon Web Services (AWS)

Build low-cost web applications with AWS.

You can use whatever CMS you like, including WordPress, Drupal, and more. Get started for free.

All related (34)

Recommended

Pete Gannett

Ph.D. Chemistry, University of Wisconsin-Madison, (1982)2y

Seems to be an ideal gas law question. The relevant equation is:

PV = nRT

where P is the pressure in atmospheres, V is the volume in liters, n is the number of moles of gas, R is the gas constant (0.082 atm-L/mole-deg K), and T is temperature in Kelvins. STP means standard temperature and pressure and this is taken as 1 atm and 0º C or 273 K.

To calculate the number of molecules we will use the constant 6.023 * 10^23 molecules/mole and, therefore, we will need to know the number of moles (n). So, first we’ll rearrange the gas law equation, isolating ’n’ and then put the numbers in.

n = PV/RT = 1 * 1 / (0.082)(273) = 0.0447 moles

So, to calculate the number of molecules, multiple this by the number of molecules in a mole and you get:

# molecules of nitrogen in 1 Liter at STP = 6.023 * 10^23 molecules/mole * 0.0447 moles = 2.6905 * 10^22 molecules

Note, it does not matter what the gas is.

6 0

2 years ago

Read 2 more answers

When an atom combines chemically with another atom it either gains loses or shares?

Leokris [45]

When an atom combines chemically with another atom, it either gains, loses, or shares ELECTRONS.

7 0

3 years ago