【简答题】目前( )是世界最大的棉花生产和消费国。
【单选题】阅读下面程序 import java.io.*; public class TypeTransition{ public static void main(String args[]){ char a='h'; int i=100; int j=97; int aa=a+i; System.out.println('aa='+aA) ; char bb=(char)j; System.out.pr...
【单选题】用25ml吸管移出溶液的准确体积应记录为( )。
【单选题】用 25ml 移液管移出的溶液体积应记录为 ( C )
【单选题】A 25.0 mL sample of 0.15 M silver nitrate, AgNO3, is reacted with a 3.58 g sample of calcium chloride, CaCl2 (M = 111.0). Which of the following statements is true?
A.
Silver nitrate is the limiting reactant and calcium nitrate precipitates.
B.
Silver nitrate is the limiting reactant and silver chloride precipitates.
C.
Calcium chloride is the limiting reactant and calcium nitrate precipitates.
D.
Calcium chloride is the limiting reactant and silver chloride precipitates.
【简答题】100mL 0.100mol/L HA弱酸溶液,用25.0mL乙醚萃取,萃取后取出25.0mL水相,需20.0mL0.0500mol/L NaOH溶液与之中和,计算HA在有机相与水相中的比值为多少?
【单选题】下面程序的输出是( )。
B.
intf(“%d%d%d”,i*=2,++i,i++) ;