Metandienone Wikipedia
Atrazine – General Overview
Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)‑1,3,5‑triazine) is a widely used herbicide that suppresses the growth of annual grasses and broadleaf weeds in crops such as corn, sugarcane, cvcentrum.eu sorghum, and some horticultural commodities. Its mode of action involves inhibition of photosynthetic electron transport (specifically blocking plastoquinone reduction), thereby preventing photosynthesis in susceptible weed species while leaving most crop plants largely unaffected due to their lower sensitivity or different growth stage at application.
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I. Chemical Properties
| Property | Value / Description |
|---|---|
| Molecular formula | C₆H₇N₉ |
| Molecular weight | 169.18 g mol⁻¹ |
| Appearance | Colorless to pale yellow crystals (solids) or clear colorless liquid; in commercial formulations typically white powder. |
| Solubility | Insoluble in water (<0.1 mg mL⁻¹). Soluble in organic solvents: acetone, ethanol, methanol, DMSO, and especially in petroleum distillates (e.g., kerosene, mineral oil). |
| Acid–base behavior | Weakly acidic; pKa of the imide proton ~9.5. The compound can act as a mild ligand for transition metals via its carbonyl groups. |
| Thermal stability | Decomposes above 300 °C. Sublimes at ~230 °C under reduced pressure. No significant thermal decomposition until >250 °C. |
| Photochemical behavior | Photostable in UV/visible range; no strong absorption below 350 nm, so minimal photodegradation under typical laboratory illumination. |
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2. Potential Chemical Interactions with the Sample
| Interaction | Likelihood | Impact on Measurement |
|---|---|---|
| Acid–base neutralization (sample pH ~4‑6) | Medium | Minor, could shift local equilibrium if sample contains weak acids/bases; not expected to produce measurable signals. |
| Redox reaction with oxidizable analytes | Low | Sample may contain antioxidants or reducing agents that could reduce the anhydride; but no strong oxidizing species present. |
| Hydrolysis to maleic acid (in presence of water/acid) | Medium | Maleic acid formation is a reversible reaction; however, in dilute aqueous solution equilibrium favors anhydride at neutral pH and low ionic strength. |
| Complexation with metal ions (e.g., Ca²⁺, Mg²⁺) | Low | No high-affinity complexes known between maleate and common divalent cations under neutral conditions. |
Interpretation: The most plausible interference is the hydrolysis of maleic anhydride to maleic acid, which could shift the equilibrium toward the open form, thereby reducing the concentration of the species responsible for the observed optical activity.
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3. Quantitative Estimation of Maleate Concentration in Solution
Given:
- Initial maleic anhydride mass: 0.1 g
- Density (maleic anhydride): \( ho = 1.24~\textg/mL \)
- Solution volume: 10 mL of water
| Step | Description | Calculation |
|---|---|---|
| 1 | Convert mass to moles (using molar mass \(M = 100.06~\textg/mol\)) | \( n = \frac0.1~\textg100.06~\textg/mol = 9.99\times10^-4~\textmol \) |
| 2 | Compute concentration in mol/L (Molarity) | \( C = \fracnV_\textL = \frac9.99\times10^-4~\textmol0.01~\textL = 0.0999~\textM \approx 0.1~\textM \) |
| 3 | Convert to mol/m³ (SI units) | \( C_\textm^-3 = C\times10^3=99.9~\textmol/m^3\approx100~\textmol/m^3 \) |
Result
The concentration of the dissolved substance in the 0.01 L sample is
[
C \simeq 1.0\times10^-1\;m mol\,L^-1
= 1.0\times10^2\;m mol\,m^-3 .
]
(If you need a different unit, just multiply or divide by the appropriate factor.)
