Overuse of the same chemicals can result in the pest becoming immune to the pesticides.
Answer:
The pH of the sample is 3,4.
Explanation:
We calculate the pOH from the formula pOH = -log (OH-). We know that for all aqueous solutions: pH + pOH = 14, and from there we clear pH:
pOH= -log (OH-)=10,60
pH + pOH = 14
pH + 10,60 = 14
pH=14 -10,60
<em>pH=3,4</em>
Answer:
23.8g of sodium phosphate are formed
Explanation:
Based on the reaction of sodium, Na, with phosphoric acid, H₃PO₄:
3Na + H₃PO₄ → Na₃PO₄ + 3/2 H₂
<em>3 moles of sodium produce 1 mole of sodium phosphate</em>
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To solve this question we must find the moles of sodium in 10g. Using the chemical reaction we can find the moles -And the mass- of sodium phosphate produced, as follows:
<em>Moles Na -Molar mass: 22.99g/mol-</em>
10g * (1mol / 22.99g) = 0.435 moles Na
<em>Moles Na₃PO₄:</em>
0.435 moles Na * (1mol Na₃PO₄ / 3mol Na) = 0.145 moles Na₃PO₄
<em>Mass Na₃PO₄ -Molar mass: 163.94g/mol-</em>
0.145 moles Na₃PO₄ * (163.94g/mol) =
<h3>23.8g of sodium phosphate are formed</h3>
