Instrument used to measure atmospheric pressure

The mass fractions of a mixture of gases are 15 percent nitrogen, 5 percent helium, 60 percent methane, and 20 percent ethane wi

Setler79 [48]

Answer:

Explanation:

mass fraction N₂ : He : CH₄ : C₂H₆ : : 15 : 5 : 60 : 20

mole fraction N₂ : He : CH₄ : C₂H₆ : : 15/28 : 5/4 : 60/16 : 20/30

mole fraction N₂ : He : CH₄ : C₂H₆ : : .5357 : 1.25 : 3.75 : .67

Total mole fractions = .5357 + 1.25 + 3.75 + 0.67 = 6.2057

mole fraction of N₂ = .5357 / 6.2057 = .0877

mole fraction of He = 1.25 / 6.2057 = .20

mole fraction of CH₄ = 3.75 / 6.2057 = .6043

mole fraction of C₂H₆ = .67 / 6.2057 = .108

Partial pressure = total pressure x mole fraction

Partial pressure of N₂ = 1200 kPa x .0877 = 105.24 kPa

Partial pressure of He = 1200 kPa x .20 = 240 kPa

Partial pressure of CH₄ = 1200 kPa x .6043 = 725.16 kPa

Partial pressure of C₂H₆ = 1200 kPa x .108 = 129.6 kPa

6 0

3 years ago

Which of the following is not a benefit of the water cycle?

BigorU [14]

Answer:

4th line

Explanation:

-water cycle helps regulate the temperature on the Earth.

8 0

3 years ago

Read 2 more answers

If volumes are additive and 253 mL of 0.19 M potassium bromide is mixed with 441 mL of a potassium dichromate solution to give a

Alexxx [7]

Answer:

The concentration of the Potassium Dichromate solution is 0.611 M

Explanation:

First of all, we need to understand that in the final solution we'll have potassium ions coming from KBr and also K2Cr2O7, so we state the dissociation equations of both compounds:

KBr (aq) → K+ (aq) + Br- (aq)

K2Cr2O7 (aq) → 2K+ (aq) + Cr2O7 2- (aq)

According to these balanced equations when 1 mole of KBr dissociates, it generates 1 mole of potassium ions. Following the same thought, when 1 mole of K2Cr2O7 dissociates, we obtain 2 moles of potassium ions instead.

Having said that, we calculate the moles of potassium ions coming from the KBr solution:

0.19 M KBr: this means that we have 0.19 moles of KBr in 1000 mL solution. So:

1000 mL solution ----- 0.19 moles of KBr

253 mL solution ----- x = 0.04807 moles of KBr

As we said before, 1 mole of KBr will contribute with 1 mole of K+, so at the moment we have 0.04807 moles of K+.

Now, we are told that the final concentration of K+ is 0.846 M. This means we have 0.846 moles of K+ in 1000 mL solution. Considering that volumes are additive, we calculate the amount of K+ moles we have in the final volume solution (441 mL + 253 mL = 694 mL):

1000 mL solution ----- 0.846 moles K+

694 mL solution ----- x = 0.587124 moles K+

This is the final quantity of potassium ion moles we have present once we mixed the KBr and K2Cr2O7 solutions. Because we already know the amount of K+ moles that were added with the KBr solution (0.04807 moles), we can calculate the contribution corresponding to K2Cr2O7:

0.587124 final K+ moles - 0.04807 K+ moles from KBr = 0.539054 K+ moles from K2Cr2O7

If we go back and take a look a the chemical reactions, we can see that 1 mole of K2Cr2O7 dissociates into 2 moles of K+ ions, so:

2 K+ moles ----- 1 K2Cr2O7 mole

0.539054 K+ moles ---- x = 0.269527 K2Cr2O7 moles

Now this quantity of potassium dichromate moles came from the respective solution, that is 441 mL, so we calculate the amount of them that would be present in 1000 mL to determine de molar concentration:

441 mL ----- 0.269527 K2Cr2O7 moles

1000 mL ----- x = 0.6112 K2Cr2O7 moles = 0.6112 M

6 0

3 years ago

Fluorine has an atomic number of 9, how many electron shells does it have?

aleksandr82 [10.1K]

2 shells because if you do the electronic configuration:
2,7 which adds up to 9
7 stands for the group it in and it also stands for how many electrons are in the outer shell.
the amount of spaces stands for which period its in therefore it in period 2

4 0

3 years ago

Weak noncovalent interactions:__________ a. do not include ionic interactions b. always involve water. c. can have a large cumul

valentina_108 [34]

Answer:

c. can have a large cumulative effect

Explanation:

Noncovalent interactions between molecules are weaker than covalent interactions. Noncovalent interactions between molecules are of various types which include van der Waals forces, hydrogen bonding, and electrostatic interactions or ionic bonding.

van der Waals forces are weak interactions found in all molecules. They include dipole-dipole interactions - formed due to the differences in the electronegativity of atoms - and the London dispersion forces.

Hydrogen Bonds results when electrons are shared between hydrogen and a strongly electronegative atoms like fluorine, nitrogen, oxygen. The hydrogen acquires a partial positive charge while the electronegative atom acquires a partial negative. This results in attraction between hydrogen and neighboring electronegative molecules.

Ionic bonds result due to the attraction between groups with opposite electrical charges, for example in common salt between sodium and chloride ions.

Even though these noncovalent interactions are weak, cumulatively, they exert strong effect. For example, the high boiling point of water and the crystal structure of ice are due to hydrogen bonding.

7 0

3 years ago