【简答题】(10分)为了合理利用化学能,确保安全生产,化工设计需要充分考虑化学反应的反应热,并采取相应措施。化学反应的反应热通常用实验进行测定,也可进行理论推算。 (1) 实验测得,5g甲醇在氧气中充分燃烧生成二氧化碳气体和液态水时释放出113.5kJ的热量,则甲醇的燃烧热ΔH= 。 (2)今有如下两个热化学方程式:则a b(填>, =' ,' H 2 (g)+ O 2 (g) = H 2 O(g) ΔH...
【简答题】Complete the following sentences with what you hear on the tape. 1) These men and women work for ___________, _______ and _________. They belong to the______________________________ . 2) Her picture _...
【单选题】购买劳动力的资本之所以属于流动资本是因为( )。
【单选题】以对象群体的平均水平或常模为参照点,确定评价对象在群体的相对位置的评价方式为
【判断题】效标参照性测验又称相对性测验,是以对象群体的平均水平(常模)为参照点,确定评价对象在群体中相对位置的一种测验方式。
【简答题】Fitness A study has shown 1 fitness is the key to long life, regardless of body shape or even smoking habits. Researchers discovered that people 2 exercise live longer than those 3 do not. It is clear...
【简答题】It is well known that if one wants to maximize the life income through a college education, he/she needs to 1) _ and 2) _. However, this myth is denied since it lacks supporting 3)_. For years evidenc...
【简答题】For decades, scientists have been fascinated by the ____1____ that Earth’s next-door neighbor once harbored life. And although no hard ____2____ has yet been found, scientists are still hopeful that s...
【单选题】关系代数中π运算符对应select语句中的()子句