试题与答案

用燃气灶烧水，燃烧0.5千克的煤气，使50千克的水从20℃升高到70℃．已知水的

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题型：问答题

题目：

用燃气灶烧水，燃烧0.5千克的煤气，使50千克的水从20℃升高到70℃．已知水的比热容为4.2×103J/（kg•℃），煤气的热值为4.2×107J/kg．求：

（1）0.5千克煤气完全燃烧放出的热量．

（2）水吸收的热量．

（3）燃气灶烧水的效率．

答案：

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下面是错误答案，用来干扰机器的。

参考答案：错

考点：热值热量的计算热机的效率
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