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poizon [28]
3 years ago
15

A field worker is exposed to a xylene for a duration of 8 weeks at 40 hrs/wk. The concentration of xylene in the workplace is 40

μg/m3. The worker is inhaling air at a rate of 0.9 m3/hr. Assuming 70 kg body mass, the chronic daily intake (CDI) [mg/(kg-d)] during the period of exposure is most nearly.
Chemistry
1 answer:
Andrej [43]3 years ago
5 0

Answer:

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.

Explanation:

Number of hours worker exposed to xylene = 40 hr/week\times 8 week = 320 hours

The concentration of xylene in the workplace =40 \mu g/m^3

The worker is inhaling air at a rate of 0.9 m^3/hr.

Amount xylene inhaled by worker in an hour :

= 40\mu g/m^3\times 0.9 m^3/hr=36 \mu g/hr

Amount xylene inhaled by worker in 320 hours:

36 \mu g/hr\times 320 hr=11,520 \mu g=11,520\times 0.001 mg=11.520 mg

1 μg = 0.001 mg

Amount xylene inhaled by worker in 320 hours = 11.520 mg

1 day = 24 hours

Amount xylene inhaled by worker in 1 day:

\frac{24}{320}\times 11.520 mg=0.864 mg

Assuming 70 kg body mass, the chronic daily intake of xylene :

\frac{0.864 mg/day}{70 kg}=0.01234 mg/ kg day\approx 0.012 mg/ kg day

The chronic daily intake during the period of exposure is most nearly 0.012 mg/kg day.

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Blow a lot of air into it you can stick an air pump and when your done pumping quickly put tape over the hole
5 0
3 years ago
If the a of a monoprotic weak acid is 2. 6×10−6, what is the ph of a 0. 33 m solution of this acid?
yawa3891 [41]

The pH of the monoprotic weak acid is 2.79.

<h3>What are weak acids?</h3>

The weak acids are the acids that do not fully dissociate into ions in the solution. Strong acids fully dissociate into ions.

The chemical reaction is HA(aq) ⇄ A⁻(aq) + H⁺(aq).

c (monoprotic acid) = 0.33 M.

Ka = 1.2·10⁻⁶

[A⁻] = [H⁺] = x

[HA] = 0.33 M - x

Ka = [A⁻]·[H⁺] / [HA]

2. 6 × 10⁻⁶ = x² / (0.33 M - x)

Solve quadratic equation: [H⁺] = 0.000524 M.

pH = -log[H⁺]

pH = -log(0.000524 M)

pH = 2.79

Thus,  the pH of the monoprotic weak acid is 2.79

To learn more about weak acids, refer to the below link:

brainly.com/question/13032224

#SPJ4

5 0
2 years ago
Which reaction is a decomposition reaction? A. 2KClO3 → 2KCl + 3O2 B. 4Na + O2 → 2Na2O C. ZnS + 3O2 → 2ZnO + 2SO2 D. 2NaBr + CaF
Vedmedyk [2.9K]

Answer:

  • <em><u>Option A. </u></em><u><em>2KClO₃ → 2KCl + 3O₂</em></u>

Explanation:

There are five basic general types of chemical reactions:

  • Decomposition reactions
  • Synthesis or combination reaction
  • Single replacement reactions
  • Double replacement reactions
  • Combustion reactions

The given reactions are:

  • <u>2KClO₃ → 2KCl + 3O₂</u>

Which is, indeed, a decomposition reaction because the reactant, KClO₃, is a single substance that undergoes a reaction in which it yields two new substances, known as products: KCl and O₂.

  • <u>4Na + O₂ → 2Na₂O</u> is a synthesis or combination reaction because two reactants, Na and O₂, combine for the formation of one single new product, Na₂O.

  • <u>ZnS + 3 O₂ →  2ZnO + 2SO₂ </u>is a single replacement reaction because oxygen is replacing Zn and S in ZnS to form ZnO and plus SO₂.

  • <u>2NaBr + CaF₂ → 2NaF + CaBr₂ </u>is a double replacement reaction because two  ions (Br⁻ from NaBr and F⁻ from CaF₂) are exchanging places with other two ions (Na⁺ from NaBr and Ca²⁺ from CaF₂) two form two new ionic compounds (NaF and CaBr₂).
4 0
3 years ago
Individual solute particles are broken apart from the solid by these particles. * a Solution b Insoluble c Solvent d Compounds
Maru [420]

Answer:

Individual solute particles are broken apart from the solid by the;

c. Solvent

Explanation:

A solution is the homogeneous mixture that is made up of two or more substances formed by dissolving a substance which can be a solid, liquid or gas in another substance known as the solvent which normally the larger part of the fraction of the solution than the solute and can also be a solid, liquid or a gas

In a solution the solvent particles serves to brake of and disperser parts of a solid solute to form a more or less homogeneous mixture

Therefore, the solute particles are broken by the <u>solvent</u> particles in a solution

7 0
3 years ago
7. An element's most stable ion forms an ionic compound with chlorine having the formula XCl2. If the ion of element X has a mas
Serhud [2]

Answer:

The element is strontium and the number of neutrons it have is 51.

Explanation:

Based on the given information, the ionic compound is,  

XCl₂ ⇔ X₂⁺ + 2Cl⁻

X2+ is the ion of the mentioned element

As mentioned in the given question, the number of electrons of the element X is 36 and as seen from the reaction the charge present on the ion is +2. Now the atomic number will be,  

No. of electrons = atomic number - charge

36 = atomic number - 2

Atomic number = 38

Based on the periodic table, the atomic number 38 is for strontium element, and the sign of strontium is Sr. Hence, the element X is Sr.  

Now based on the given information, the mass number of the element is 89. Now the no. of neutrons will be,  

No. of neutrons = mass number - atomic number

= 89 - 38

= 51 neutrons.  

4 0
3 years ago
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