题干

已知热化学方程式:

①C(金刚石,s)+O2(g)=CO2(g) ΔH1    ②C(石墨,s)+O2(g)=CO2(g) ΔH2

③C(石墨,s)=C(金刚石,s) ΔH3=1.9 kJ·mol-1下列说法正确的是(  )

A: 石墨转化成金刚石的反应是吸热反应

B: 金刚石比石墨稳定

C: ΔH3=ΔH1-ΔH

D: ΔH1>ΔH2

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答案(点此获取答案解析)

A

同类题1

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    When Abraham Lincoln was young, he worked in a store. One day a woman came into the store and bought some things. They added up to two dollars and six and a quarter cents.

    The bill was paid, and the woman was satisfied. But the young storekeeper, not feeling quite sure about his calculations(计算), added up the things again. To his surprise, he found that it should have been but two dollars.

    “I've made her pay six and a quarter cents more,” said young Abe, upset.

    It was an unimportant thing, and many salespersons would forget it, but Abe was too careful for that.

    The money must be paid back, he decided.

    At night, he closed the store and walked to the home of his customer. He explained the matter, paid over the six and a quarter cents, and returned satisfied.

    Here is another story of young Lincoln's strict honesty. A woman entered the store and asked for half a pound of tea. The young man weighed it out. This was the last sale of the day.

    The next morning, when beginning his duties, Abe discovered a four-ounce weight on the scales(磅砰). It flashed upon him at once that he had used this in the sale last night, and so, of course, given his customer short weight. Many people would not have been much worried by this discovery. But Abe weighed out four ounces of the tea, shut up the store, and carried it to the customer. I think that the name, so often given in late times to President Lincoln, of “Honest Old Abe", was well deserved(应得的).

同类题3

阅读下面的文言文,完成下列小题

    于烈,善射,少言,有不可犯之色。少拜羽林中郎,累迁侍中、殿中尚书。于时孝文幼冲,文明太后称制,烈与元丕、陆睿、李冲等各赐金策,许以有罪不死。及迁洛阳,人情恋本,多有异议。帝问烈曰:“卿意云何?”烈曰:“陛下圣略深远,非愚管所测。若隐心而言,乐迁之与恋旧,唯中半耳。”帝曰:“卿既不唱异,即是同,深感不言之益。宜且还旧都,以镇代邑。”镇代,留台庶政,一相参委。十九年,大选百僚,烈子登引例求进。烈表引己素无教训,请乞黜落。帝曰:“此乃有识之言,不谓烈能辨此!”乃引见登诏曰朕今创礼新邑明扬天下卿父乃行谦让之表而有直士之风故进卿为太子翊军校尉,又加烈散骑常侍,封聊城县子。宣武即位,宠任如前。咸阳王禧为宰辅,权重当时。曾遣家僮传言于烈,求旧羽林武贲执仗出入。烈不许。禧复遣谓烈曰:“我是天子叔,元辅之命,与诏何异?”烈厉色答曰:“向亦不道王非天子叔。若是诏,应遣官人所由。若遣私奴索官家羽林,烈头可得,羽林不可得也!”禧恶烈刚直,出之为恒州刺史。烈不愿藩授,遂以疾辞。宣武以禧等专擅,潜谋废之。会二年正月初祭,三公并致裔于庙,帝夜召烈子忠谓曰:“卿父明可早入,当有处分。”及明,烈至。诏曰:“诸父慢怠,渐不可任,今欲使卿以兵召之,卿其行乎?”烈曰:“老臣历奉累朝,颇以干勇赐识。今日之事,所不敢辞。”乃将直阁以下六十余人,宣旨召咸阳王禧、彭城王勰、北海王详,卫送至帝前。诸公各稽首归政。以烈为散骑常侍、车骑大将军,晋爵为侯。自是长直禁中,机密大事,皆所参焉。咸阳王禧之谋反,宣武从禽于野。左右分散,仓卒之际,莫知其计。乃敕烈子忠驰觇虚实。烈时留守,已处分有备。因忠奏曰:“臣虽朽迈,心力犹可。愿缓跸徐还,以安物望。”帝甚以为慰。车驾还宫,禧已逃,诏烈追执之。顺后既立,以世父之重,弥见优礼。及卒,宣武举哀于朝堂,给东园第一秘器,赠太尉,封钜鹿郡公。

(节选自《魏书•于烈传》)