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4 years ago

What mass of helium is in a 2.00L ballon at STP

Chemistry

1 answer:

MAXImum [283]4 years ago

6 0

Answer:

0.357 g He

Explanation:

1 mol of gas at STP = 22.4 L

2.00 L * 1 mol/22.4 L = 0.08929 mol He

M(He) = 4.00 g/mol

0.08929 mol He * 4.00 g/ 1 mol He = 0.357 g He

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An aqueous nacl solution is made using 112 g of nacl diluted to a total solution volume of 1.00 l. calculate the molarity, molal

worty [1.4K]

Q1)
molarity is defined as the number of moles of solute in 1 L of solution.
the NaCl solution volume is 1.00 L
number of moles NaCl = NaCl mass present / molar mass of NaCl
NaCl moles = 112 g / 58.5 g/mol = 1.91 mol
the number of moles of NaCl in 1.00 L of solution is - 1.91 mol
therefore molarity of NaCl is 1.91 M

Q2)
molality is defined as the number of moles of solute in 1 kg of solvent.
density is mass per volume.
density of the solution is 1.08 g/mL.
therefore mass of the solution is = density x volume
mass = 1.08 g/mL x 1000 mL = 1080 g
since we have to find the moles in 1 kg of solvent
mass of solvent = 1080 g - 112 g = 968 g
number of moles of NaCl in 968 g of solvent - 1.91 mol
therefore number of NaCl moles in 1000 g - (1.91 mol / 968 g) x 1000 g/kg = 1.97 mol/kg
molality of NaCl solution is 1.97 mol/kg

Q3)
mass percentage is the percentage of mass of solute by total mass of the solution
mass percentage of solution = mass of solute / total mass of the solution
mass of solute = 112 g
total mass of solution = 1080 g
mass % of NaCl = 112 g / 1080 g x 100%
therefore mass % of NaCl = 10.4 %
answer is 10.4 %

5 0

3 years ago

Which substances can decrease the solubility of CaSO4? how can i identify which substances to use on the solubility table? i sup

natulia [17]

Do not know this answer

4 0

3 years ago

The concentration of ag+ in a solution saturated with ag2c2o4(s) is 1.7 × 10-4 m. calculate ksp for ag2c2o4.

Gelneren [198K]

<span>Silver oxalate dissociation equation is following:
</span><span>
Ag</span>₂C₂O₄(s) ⇄ 2Ag⁺(aq) + C₂O₄²⁻(aq)

According to reaction follows next stoichiometric ratio:

[Ag⁺] : [C₂O₄²⁻] = 2 : 1

[C₂O₄²⁻] = [Ag⁺] / 2

[C₂O₄²⁻] = (1.7×10⁻⁴)/2 = 8.5×10⁻⁵ M

So, solubility product constants for silver oxalate is:

Ksp = [Ag⁺]² x [C₂O₄²⁻]

Ksp = [1.7×10⁻⁴]² x [8.5×10⁻⁵]

Ksp = 2.46×10⁻¹²

4 0

3 years ago

What is a major problem with CFCs?

oksian1 [2.3K]

The major problem with CFCs is that It is a greenhouse gas, Option A is correct.

Chlorofluorocarbons (CFCs) are nontoxic, nonflammable chemicals containing atoms of carbon, chlorine, and fluorine.

They are used in the manufacture of aerosol sprays, blowing agents for foams and packing materials, as solvents, and as refrigerants.

CFCs are classified as halocarbons, a class of compounds that contain atoms of carbon and halogen atoms

The major problem with CFC's is that they are green house gases

It destroys ozone in the upper atmosphere (stratosphere).

CFCs can produce more than 10,000 times as much warming, pound for pound, once they are in the air.

It is not only because of their dramatic warming potential but also

They were found to be the primary cause of the rapidly escalating destruction of the Earth’s ozone layer,

which protects the planet from dangerous, cancer-causing levels of ultraviolet radiation.

Therefore The major problem with CFCs is that It is a greenhouse gas, Option A is correct.

To know more about CFC'S

brainly.com/question/14330630

#SPJ1

6 0

2 years ago

How do you perform calculations relating to isotopes. describe please

Zigmanuir [339]

Explanation:

I'm not sure if this is what you are looking for but i will attempt to answer.

Isotopes are variations of the same atom. They have the same number of protons but have a different number of neutrons. As a result of this, the atomic number remains the same but the mass number changes.

A calculation you could perform in relation to isotopes would be calculating the relative atomic mass. The relative atomic mass is the weighted average of masses of isotopes.

Relative atomic mass (RAM)= the addition of

$\frac{relative \: isotopic \: mass \times percentage \: abundance}{100 }$

For example, the element Indium has a relative isotopic mass of 112.90406, 4.29% of the time. It has a relative isotopic mass of 114.903878, 95.71% of the time.

From this

RAM=

$\frac{112.904061 \times 4.29}{100} + \frac{114.903878 \times 95.71}{100} = 114.8(4 \: sig \: figs)$

8 0

3 years ago