有多快？化学变化的速率
国际文凭组织 · IB Diploma · 化学 · HL 知识点 17 3:47 英语旁白 · 英中内嵌字幕
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A faster reaction finishes sooner, but it need not make more product.
更快的反应完成得更早，但不一定产生更多产物。
Rate 速率 and final yield answer different questions.
速率和最终产率回答的是不同的问题。
Reaction rate describes reactant used or product formed per time.
反应速率描述单位时间内反应物的消耗量或生成物的形成量。
Higher temperature increases the fraction of collisions with enough energy.
升高温度会增加具有足够能量的碰撞所占的比例。
A catalyst provides an alternative pathway with lower activation energy.
催化剂提供一条活化能较低的替代路径。
Activation energy is the energy barrier for a reaction pathway.
活化能是反应路径的能量壁垒。
Rate is the change in a measured quantity per unit time.
反应速率是指单位时间内测量量的变化。
A product-time graph has a steeper gradient where rate is larger.
产物-时间图中，速率较大的位置斜率更陡。
A tangent estimates instantaneous rate; a secant gives average rate over an interval.
切线用于估算瞬时速率；割线给出某区间内的平均速率。
The final plateau reflects the total collected product under the stated conditions.
最终平台期反映了在指定条件下收集到的总产物量。
In the lab: For gas production, check apparatus for leaks, start timing consistently and record volume at regular intervals.
在实验室中，对于气体生成实验，需检查装置是否漏气，保持计时一致，并定期记录体积。
Keep concentration, reactant amount and surface area controlled when changing temperature.
改变温度时，须控制浓度、反应物用量和表面积不变。
Known: gas volume increases from 10 to 34 cubic centimetres between 20 and 60 seconds.
已知：气体体积在20秒到60秒之间从10增加到34立方厘米。
Average rate equals change in volume divided by change in time.
平均速率等于体积变化量除以时间变化量。
Rate equals 34 minus 10, all over 60 minus 20, which is 0.60 cubic centimetres per second.
速率等于34减10，除以60减20，即0.60立方厘米每秒。
This is not necessarily the instantaneous rate at 40 seconds.
这不一定是在40秒时的瞬时速率。
Your turn: A reaction makes 24 cubic centimetres of gas in 40 s.
轮到你了。 某反应在40秒内生成24立方厘米的气体。
Find average rate.
求平均速率。
A catalyst does not change the equilibrium constant at a fixed temperature.
催化剂不会改变固定温度下的平衡常数。
A mass-loss method cannot detect all reactions, and losing gas through a leak biases a collection experiment.
质量损失法无法检测所有反应，且气体通过泄漏流失会使收集实验产生偏差。
Not true: A faster reaction always produces a larger final amount of product.
这种说法不正确。 反应速率更快并不一定意味着最终生成的产物量更多。
Rate measures how quickly product forms, not how much finally forms.
反应速率衡量的是产物生成的快慢，而非最终产物的总量。
The final amount is fixed by the limiting reagent; a catalyst or powder changes only the time taken to reach it.
最终产量由限量反应物决定；催化剂或粉末仅能缩短达到该产量所需的时间。
Reaction rate describes reactant used or product formed per time.
反应速率描述单位时间内反应物的消耗量或生成物的生成量。
A product-time graph has a steeper gradient where rate is larger.
在产物-时间图中，速率较大的位置斜率更陡。
Watch for: A catalyst does not change the equilibrium constant at a fixed temperature.
请注意：催化剂不会改变固定温度下的平衡常数。
Gas volume rises from 8 to 20 cubic centimetres between 10 seconds and 40 seconds.
气体体积在10秒到40秒之间从8立方厘米增加到20立方厘米。
Find the average rate.
求平均速率。
A faster rate does not increase the final amount.
更快的速率不会增加最终产量。
The result is an average rate of 0.40 cubic centimetres per second.
结果是平均速率为每秒0.40立方厘米。
Between 20 and 60 seconds the volume rises from 10 to 34 cubic centimetres, an average of 0.60 per second.
在20秒到60秒之间，体积从10立方厘米增加到34立方厘米，平均每秒0.60。
The curve flattens as the reactants are used up.
随着反应物被消耗，曲线逐渐变平。
Fictional gas volumes at 0, 20 and 40 seconds are 0, 18 and 24 cubic centimetres.
虚构的气体体积在 0、20 和 40 秒时分别为 0、18 和 24 立方厘米。
Compare interval rates.
比较各区间的速率。
Can the average from 0 to 40 seconds be called the instantaneous rate at 20 seconds?
0 到 40 秒的平均速率能称为 20 秒时的瞬时速率吗？
The interval rates are 0.90, then 0.30 cubic centimetres per second; overall 0.60.
两段时间内的平均速率依次为 0.90 和 0.30 cm³/s，整体为 0.60 cm³/s。
A secant does not in general give the tangent at 20 seconds.
割线一般不能代替 20 秒处的切线。
More closely spaced data are needed for the instantaneous estimate.
要估计瞬时速率，需要间隔更密的数据。
Retrieve the technical meanings, then vary one input in the original transfer and justify the model condition.
请回顾相关技术术语的含义，然后在原始传递过程中改变一个输入变量，并为模型条件提供依据。