Aspirin(3) was synthesized by esterification reaction of salicylic acid(1) with acetic anhydride(2) catalyzed by aluminum dihydrogen tripolyphosphate/loaded sulfur diatomite. The effects of materials ratio[r = n(2) ∶ n(1) ],reaction time,temperature and catalyst amount on the yield of 3were investigated by the single-factor experiments. The results showed that the four main factors influencing the yield of 3 are in the following order: r reaction time reaction temperature catalyst amount. Under the optimum reaction conditions[1 was 50 mmol,the catalyst amount was 5%,r was3. 14,at 81 ℃ for 40 min],the yield was 88. 6%. The yield still reach 83. 3% after reuse for five times of the catalyst
Answer:
pH = 11.30
Explanation:
pH is defined as -log [H⁺]
To find [H⁺] from [OH⁻] -Concentration of hydroxide ion-, we must use the equilibrium of water:
H₂O(l) ⇄ H⁺(aq) + OH⁻(aq)
Keq = 1x10⁻¹⁴ = [H⁺] [OH⁻]
[H⁺] = 1x10⁻¹⁴ / [OH⁻]
[H⁺] = 1x10⁻¹⁴ / 2x10⁻³M
[H⁺] = 5x10⁻¹²M
pH = -log (5x10⁻¹²M)
<h3>pH = 11.30</h3>
A sound is first produced by making something VIBRATE<span>. The sound then travels through a </span><span>MEDIUM</span><span> to reach the ears, which are the parts of the body that allow for sounds to be heard.</span>
Acid rain<span> is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as </span>acid rain<span>.</span>
