Re: [計量] PP1-PS
※ 引述《aaaaaakoyasu (六點半天色還沒亮)》之銘言：
: The rate of a certain chemical reaction is directly proportional to the
: square of the concentration of chemical A present and inversely proportional
: to the concentration of chemical B present. If the concentration of chemical
: B is increased by 100 percent, which of the following is closest to the
: percent change in the concentration of chemical A required to keep the
: reaction rate unchanged?
: (A) 100% decrease
: (B) 50% decrease
: (C) 40% decrease
: (D) 40% increase
: (E) 50% increase
: 題目看沒有很懂...拜託了<(_ _)>
反應速率R與A^2成正比
與 B 成反比
所以R = A^2 / B
令新的反應速率 R` = A`^2 / B` 由題目得知 B` = 2B
若速率不變則 R` = R 由關係式得知 A`^2 = 2*A^2
則A`=(根號2)*A 變動率為 (根號2)-1 = 1.414 -1 = 40% #
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11/06 09:51, , 1F
11/06 09:51, 1F
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