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3 years ago

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Chemistry

1 answer:

deff fn [24]3 years ago

4 0

Answer:

The concentration given here is in terms of molality which is moles of solute per kg of solution. Therefore, we multiply the concentration by the total mass of the solution and obtain the moles of solute. We can convert this into grams and calculate for the solvent.

0.630 mol KBr / kg solution ( .086 kg solution ) = 0.0542 mol KBr

0.0542 mol Kbr ( 119.002 g / 1 mol ) = 6.4475 g KBr

Mass of solvent = 86 - 6.4475 = 79.55 g water

Explanation:

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Translation: Explain the importance of energy levels,

tigry1 [53]

Answer: Formation of a stable Duplet or Octet structure

Explanation:

Energy levels refers to the definite amount of energies that electrons can have when occupying specific orbitals.

Examples are:

Level 1 as in 1s

Level 2 as in 2s, 2p

Level 3 as in 3s 3p 3d

Level 4 as in 4s 4p 4d 4f

Level 5 as in 5s .......

Level 6 as in 6s .........

Electrons can be excited to higher energy levels by absorbing energy from the surroundings during chemical reactions and so forming chemical bonds like ionic, covalent etc.

A perfect example is Sodium (Na) and Chlorine (Cl) in Sodium chloride (NaCl)

Sodium has atomic number of 11, so energy level is 1s2, 2s2 2p6, 3s1

Chlorine has atomic number of 17, so energy level is 1s2, 2s2 2p6, 3s2 3p5

You will notice that the both Na and Cl, has electrons in the energy level 3. Then, the bond formed must be one that lead to the formation of a OCTET structure: as in Na gives off its 3s1 electron TO Cl.

Thus, Cl now becomes 1s2, 2s2 2p6, 3s2 3p6 - an OCTET STRUCTURE (with completely filled outershell and full energy level 3) in NACl.

So, a duplet or Octet structure is the answer

8 0

4 years ago

A drinking water plant adds 500 grams of fluoride to a water tank containing 500,000 liters of drinking water. what is the conce

nlexa [21]

Answer is: concentration of fluoride in the water in parts-per-million is 1 ppm.
Parts-per-million (10⁻⁶) is present at one-millionth of a gram per gram of sample solution, for example mg/kg.
m(fluoride) = 500 g · 1000 mg/g = 500000 mg.
m(water) = d(water) · V(water).
m(water) = 1 kg/L · 500000 L.
m(water) = 500000 kg.
arts-per-million = 500000 mg ÷ 500000 kg = 1 mg/kg = 1 ppm.

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3 years ago

Describe what the isotopes of an element have in common and how are they different.

Neporo4naja [7]

Answer:

Isotopes of an element are atoms of the same element that have different number of neutrons.

8 0

3 years ago

Read 2 more answers

The length of a diagonal of a cube with edge length 3 in.

Lilit [14]

Answer:

Diagonal

5.196

-Hops

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3 years ago

Dinitrogen oxide (N₂O) gas was generated from the thermal decomposition of ammonium nitrate and collected over water. The wet ga

RideAnS [48]

Answer:

126.73 mL

Explanation:

The total pressure of the gas mixture is the sum of the vapor pressure of its constituents. So, the vapor pressure of N₂O(p) can be calculated:

750 = 18.85 + p

p = 750 - 18.85

p = 731.15 torr

It means that for 731.15 torr, N₂O occupied 130 mL. For the general gas equation, we know that

$\frac{p1V1}{T1} = \frac{p2V2}{T2}$

Where p is the pressure, V is the volume, T is the temperature, 1 is the initial state, and 2 the final state. For the same temperatue (21ºC), the equation results on Boyle's law:

p1V1 = p2V2, so:

731.15x130 = 750xV2

750V2 = 95049.5

V2 = 126.73 mL

4 0

4 years ago