2023鹰潭一模理数

4囻命题意图本题考查阿伏加德罗常数的应用,从化学反应的角度进行考查,有真实的反应情境,更能体现阿伏加德罗常数作为辅助计量工具的价值审题指导电解AgNO3溶液,根据阴、阳离子的放电顺序知,Ag在阴极放电,电极反应式为Age=Ag,水电离出的OH在阳极放电,电极反应式为4OH-4e=2H2O+O2↑,总反应为4AgNO3+通电2H,04Ag+4HNO,+O解题思路Cl2与H2O的反应是可逆反应,尢法计算出转移电子数,A错误;电解AgNO3溶液,阳极产生氧气,当产生0.1mo氧气时转移的电子数为04N、,B正确;1mol乙炔共用电子对数为5N,lmol甲醛共用电子对数为4N、,故!mol乙炔和甲醛的混合气体含有的共用电子对数无法计算,C借误;不知HA是强酸还是弱酸,故无法求算c(A),D错误解后反思共价键数目与共用电子对数目的计算容易出错,要引起注意。

37.(15分,除标注外,每空2分)(1)多聚半乳糖醛酸酶果胶分解酶(2)可溶性的半乳糖醛酸(3)在…定温度范内,温度升高果胶酶的活性增强,在最适温度果胶酶活性最高,超过最适温度后温度继续上升,则果胶酶的活性下降40~60℃(4)固定化酶(1分)化学结合物理吸附【解析】(1)果胶酶包括多聚半乳糖醛酸酶、果胶分解酶和果胶酯酶等(2)果胶酶能够使果胶分解成可溶性的半乳糖醛酸,从而使浑浊的果汁变得澄清。(3)表中结果显示在一定温度范围内,温度升高果胶梅的活性增强,在最适温度果胶酶活性最高,温度继续上升,则果胶酶的活性下降。果胶酶活性的最适温度范围为40~60℃。(4)采用固定化酶技术可以使酶反复利用,固定化酶技术一般采用化学结合法和物理吸附法。,

第二节One possible versionFinally, as his sob quieted, his mother pulled back to look athim. " Rex, take the bird to Mr. Blake and tell him what happened.You will never have peace if you dont face him. Mr. Blakedeserves to know the truth she said with a firm look. The walk toMr. Blake's house was difficult. Leaving his mother in the yardRex stepped to the front door with the dead turkey. He knockedhoping Mr Blake wouldnt answer. But the door openedHi, Mr: blake, Rex handed him the dead bird. When he toldthe whole story of how he killed the turkey by mistake, Rex lookedat the ground, too frightened to look up there was a momentssilence and then Mr. Blake said, Thats all right. We'll eat it fordinner today. A smile appeared on his face. Rex couldnt believewhat he had heard. As he ran home he felt as if a rock had beenlifted from his shoulders. He realized that doing the right thing wastruly easy in the end

19.【解】本题考查向量的坐标运算、直接法求点的轨迹方程以及直线与抛物线的位置关系(1)设P(x,y),因为F(2,0),M(-2,3),所以W=(x+2,y-3),0F=(2,0),P=(2-x,-y)由0,丽=可得1x+2|-√(2-x)x+y,化简得y2=8x,即动点P的轨迹C的方程为y2=8x(2)设A(x1,y1),B(x2,y2)由题意知S△wm=21FDH·y1,sAm=2FDl,hyl,y1y2<0,不妨设y1>0,y2<0.因为S△AmD=2S△BFD,所以ly1|=21y21,所以y;=-2y2,①根据题意知直线l不与x轴重合,可设直线l的方程为x=my+1联立=8x消去x,得y2-8my-8=0,则△=64m2+32>0,可得y+y2=8m,yy2=-8.②由①②联立,解得y1=4,y2=-2,m=,所以ABH=1+my-y21=1+1×14-(-2)=3①【关键点拨】此题的解题关键是将△AFD的面积是△BFD的面积的2倍转化为y1=-2y2,再结合根与系数的关系y1+y2=8m,y1y2=-8求得y,y2,m