搜题请搜索小程序“爱下问搜题”
问题 实验题

（12分）某化学兴趣小组为探究铜跟浓硫酸的反应，用如图所示的装置进行有关实验。请回答：

(1)装置A中发生的化学反应方程式为                          。

(2)装置D中试管口放置的棉花中应浸一种液体，这种液体是       ，其作用是            。

(3)装置B的作用是贮存多余的气体。当D处有明显的现象后，关闭旋塞K，移去酒精灯，但由于余热的作用，A处仍有气体产生，此时B中现象是                 。B中应放置的液体是          (填字母)。

a. 水     b. 酸性KMnO4溶液      c. 浓溴水      d. 饱和NaHSO3溶液

(4)实验中，取一定质量的铜片和一定体积18mol·L-1的浓硫酸放在圆底烧瓶中共热，直到反应完毕，发现烧瓶中还有铜片剩余，该小组学生根据所学的化学知识认为还有一定量的硫酸剩余。

①有一定量的余酸但未能使铜片完全溶解，你认为原因是              。

②下列药品中能用来证明反应结束后的烧瓶中确有余酸的是       (填字母)。

a. 铁粉      b. BaCl2溶液      c. 银粉     d. Na2CO3溶液

答案

（12分）

(1)   Cu+2H2SO4==CuSO4+SO2↑+2H2O  。

(2)   NaOH溶液 ，   吸收SO2尾气       。

(3)     广口瓶B中液体被压入漏斗中    。    d.     。

(4) ① 反应变成稀硫酸后不与铜反应 。     ②   a.  d  

单项选择题

知觉是对客观事物哪种属性的反映

A．个别

B．整体

C．主要

D．本质

E．特定
查看答案
单项选择题

Surprisingly enough, modern historians have rarely interested themselves in the history of the American South in the period before the South began to become self-consciously and distinctively " Southern"—the decades after 1815. Consequently, the cultural history of Britain’s North American empire in the seventeenth and eighteenth centuries has been written almost as if the Southern colonies had never existed. The American culture that emerged during the Colonial and Revolutionary eras has been depicted as having been simply an extension of New England Puritan culture.

However, Professor Davis has recently argued that the South stood apart from the rest of American society during this early period, following its own unique pattern of cultural development. The case for Southern distinctiveness rests_ upon two related premises: first, that the cultural similarities among the five Southern colonies were far more impressive than the differences, and second, that what made those colonies alike also made them different from the other colonies. The first, for which Davis offers an enormous amount of evidence, can be accepted without major recitations, the second is far more problematic.

What makes the second premise problematic is the use of the Puritan colonies as a basis for comparison. Quite properly,Davis decries the excessive influence ascribed by historians to the Puritans in the formation of American culture. Yet Davis inadvertently adds weight to such ascriptions by using the Puritans as the standard against which to assess the achievements and contributions of Southern colonials. Throughout, Davis focuses on the important and undeniable differences between the Southern and Puritan colonies in motives for and patterns of early settlement, in attitudes toward nature and Native Americans, and in the degree of receptivity to metropolitan cultural influences.

However, recent scholarship has ply suggested that those aspects of early New England culture that seem to have been most distinctly Puritan, such as the p religious orientation and the communal impulse, were not even typical of New England as a whole, but were largely confined to the two colonies of Massachusetts and Connecticut. Thus, what in contrast to the Puritan colonies appears to Davis to be peculiarly Southern-acquisitiveness. A p interest in polities and the law, and a tendency to cultivate metropolitan cultural models were not only more typically English than the cultural patterns exhibited by Puritan Massachusetts and Connecticut, but also almost certainly characteristic of most other early modern British colonies from Barbados north to Rhode Island and New Hampshire. Within the larger framework of American colonial life, then, not the Southern but the Puritan colonies appear to have been distinctive, and even they seem to have been rapidly assimilating to the dominant cultural patterns by the last Colonial period.

The most distinctly Puritan aspects of the early New England were typical for（）

A. New England itself

B. England

C. Mississippi

D. Connecticut
查看答案