Why do particles settle down in suspension

what is the mole fraction of neon in a mixture that contains 0.628 g of helium, 11.491 g of neon, and 7.613 g of argon?

VMariaS [17]

Answer:

0.2

Explanation:

Given parameters:

Mass of helium = 0.628g

Mass of neon = 11.491g

Mass of argon = 7.613g

Unknown:

Mole fraction of neon = ?

Solution:

The mole fraction of an element is the number of moles of that element to the total number of moles in the gas mixture.

We need to calculate the number of moles of each element first;

Number of moles = $\frac{mass}{molar mass}$

Molar mass of Helium = 4g/mol

Molar mass of Neon = 20g/mol

Molar mass of Argon = 40g/mol

Number of moles of He = $\frac{0.628}{4}$ = 0.16moles

Number of moles of Ne = $\frac{11.491}{20}$ = 0.58moles

Number of moles of Ar = $\frac{7.613}{40}$ = 0.19moles

Total number of moles = 0.16moles + 0.58moles + 0.19moles = 0.93moles

Mole fraction Neon = $\frac{0.19}{0.93}$ = 0.2

4 0

3 years ago

How many electrons would be found in the Ion who’s symbol is I-

Vesnalui [34]

Answer:

54

Explanation:

Given symbol of the element:

I⁻

Number of electrons found in an ion with the symbol:

This is a iodine ion:

For an atom of iodine:

Electrons = 53

Protons = 53

Neutrons = 74

An ion of iodine is one that has lost or gained electrons.

For this one, we have a negatively charged ion which implies that the number of electrons is 1 more than that of the protons.

So, number of electrons = 53 + 1 = 54

The number of electrons in this ion is 54

6 0

2 years ago

When 136g of glycine are dissolved in of a certain mystery liquid , the freezing point of the solution is lower than the freezin

loris [4]

The given question is incomplete. The complete question is:

When 136 g of glycine are dissolved in 950 g of a certain mystery liquid X, the freezing point of the solution is 8.2C lower than the freezing point of pure X. On the other hand, when 136 g of sodium chloride are dissolved in the same mass of X, the freezing point of the solution is 20.0C lower than the freezing point of pure X. Calculate the van't Hoff factor for sodium chloride in X.

Answer: The vant hoff factor for sodium chloride in X is 1.9

Explanation:

Depression in freezing point is given by:

$\Delta T_f=i\times K_f\times m$