题目

工业上用铜屑和浓硝酸为原料制取硝酸铜。在实际生产中，需把浓硝酸用等体积的水稀释。试简要完成下列问题： (1)用稀硝酸而不用浓硝酸的原因是_______________________________________________。 (2)从经济效益和环境保护角度考虑，设计制取硝酸铜最适宜的方法，用化学方程式表示为__________________________。 答案：(1)生成等物质的量的硝酸铜，用稀硝酸时，消耗原料较少，且产生污染物的量也较少 (2)2Cu+O2====2CuO；CuO+2HNO3====Cu(NO3)2+H2O 解析: (1)比较稀硝酸、浓硝酸分别与铜反应的方程式:Cu+4HNO3（浓）====Cu(NO3)2+2NO2↑+2H2O；3Cu+8HNO3（稀）====3Cu(NO3)2+2NO↑+4H2O；发现生成等物质的量的硝酸铜，用稀硝酸时，消耗原料较少，The game of rugby football was played at Rugby School between 1750 and 1859, but players were not allowed to run with it in their hands towards the other side’s goal. With no limit to the number of players per side, hundreds would participate in it, sometimes resulting in major injuries. The innovation(创新) of running with the ball was introduced between 1859 and 1865. The popular myth of the sport’s origin states that Rugby pupil William Webb Ellis broke the local rules by running forward with the ball in his hands in 1823. Rugby School produced the first written rules for their version of the sport in 1845.In the result that the teams still tied at the end of the match, a drop goal shootout was held. The selected kickers of the two teams would have one shot at the goal each and would take turns shooting at the goal until one of the kickers missed.In England, rugby union is widely regarded as an “establishment” sport, played mostly by members of the upper and middle classes. For example, many students at private schools and grammar schools play in rugby union. In France, rugby is also widely played and has a strong tradition in the Basque people along the border regions between Spain and France. The game is very popular in South Africa among both blacks and whites, having been introduced by English-speaking settlers in the 19th century. British colonists also brought the game with them to Australia and New Zealand, where the game is widely played. It has spread then to much of Polynesia, having particularly strong followings in Fiji, Samoa, and Tonga.An official rugby union ball is made of leather or suitable material. Rugby shirts were formerly made of cotton but are now made of a cotton and polyester (涤纶) mix. This material has the advantage of not absorbing as much water or mud as cotton alone.1.Which of the following statements is WRONG about the ancient rugby?A. Players often got injured.B. A great number of people could take part.C. Players could run forward with the ball in their hands before 1823.D. Written rules were first made in Rugby School in the 1840s.2.Why was a drop goal shootout made?A. To select outstanding players.B. To encourage the audience’s curiosity.C. To make the match exciting.D. To decide the winner of the match.3.The third paragraph mainly talks about _______.A. the popularity of rugby sportB. how rugby union was established in EnglandC. how British people spread the sportD. the origin and development of rugby4.Rugby shirts made of cotton alone ___________.A. are easy to absorb much water and mudB. are replaced by polyester shirt finallyC. are much more expensive than polyesterD. are much suitable to the players