What element is this?

Solid mixture contains MgCl2 and NaCl. When 0.5000 g of this solid is dissolved in enough water to form 1.000 L of solution, the

aksik [14]

Answer:

83,40 (w/w) %

Explanation:

The osmotic pressure (π) is defined as:

π = iMRT

Where i is Van't Hoff factor (3 for MgCl₂ and 2 for NaCl), M is molarity, R is gas contant (0,082atmL/molK) and T is temperature (298,15K)

iM = π / RT

iM = 0,01607mol/L

It is possible to write:

3x+2y = 0,01607mol/L (1)

Where x are moles of MgCl₂ and y moles of NaCl.

-M = moles of each compund because M is molarity (moles/L) and there is 1,000L-

Knowing molar mass of MgCl₂ is 95,2 g/mol and for NaCl is 58,44g/mol:

x×95,211 + y×58,44 = 0,5000g (2)

Replacing (2) in (1):

3x+2(0,0086 - 1,629x) = 0,01607mol/L

-0,258x = -0,00113

x = 0,004380 moles of MgCl₂

In grams:

0,004380 moles of MgCl₂×(95,211g/mol) = 0,417g of MgCl₂

Mass percent is:

(0,4170g of MgCl₂/0,5000g of solid) ×100 = 83,40 (w/w) %

I hope it helps!

4 0

2 years ago

A sound wave from a jackhammer travels through a section of concrete with a fixed frequency. At the concrete's boundary is mud.

Ira Lisetskai [31]

Answer:

It might be too late now, but the correct answer for the question is B.

Explanation:

According to the graph you can see when it hit the boundary of the mud it curved downward making the direction change; which then the mud probably had a hollow shell, where the speed was moving much faster.

6 0

2 years ago

Read 2 more answers

Culinary arts HELP FAST 1. Most people don't often think about science and restaurants or the food industry as

Andrews [41]

Answer:

i dont know

Explanation:

6 0

2 years ago

If 190dm of hydrogen gas collected at 20°c and 760mmHg .Calculate it's volume at stp (standard pressure=760mmHg

Andrei [34K]

Answer:

177.1 L

Explanation:

The excersise can be solved, by the Ideal Gases Law.

P . V = n . R . T

In first step we need to determine the moles of gas:

We convert T° from, C° to K → 20°C + 273 = 293K

We convert P from mmHg to atm → 760 mmHg = 1atm

1Dm³ = 1L → 190L

We replace: 190 L . 1 atm = n . 0.082 . 293K

(190L.atm) / 0.082 . 293K = 7.91 moles.

We replace equation at STP conditions (1 atm and 273K)

V = (n . R .T) / P

V = (7.91 mol . 0.082 . 273K) / 1atm = 177.1 L

We can also make a rule of three:

At STP conditions 1 mol of gas occupies 22.4L

Then, 7.91 moles will be contained at (7.91 . 22.4) /1 = 177.1L

3 0

2 years ago

Oxygen has an electronegativity of 3.5, and carbon has an electronegativity of 2.5. how is charge distributed on an oxygen atom

vlabodo [156]

When oxygen has an electronegativity of 3.5, and carbon has an electronegativity of 2.5, then the oxygen atom would have a slightly negative charge. The oxygen atom in the carbon monoxide molecule would pull more electrons to its side since it has higher electronegativity making it slightly negative and the carbon would have a slightly positive charge as it would contain less electrons. This results to the formation of a polar molecule. A polar molecule is made when the molecule contains a slightly positive end and a slightly negative end. It would have a net dipole which is a result of the partial opposing charges in the molecule.

6 0

2 years ago