下列电离方程式错误的是（ ）
A．MgSO4=Mg++SO4-
B．Na2CO3=2Na++CO32-
C．Ba（OH）2=Ba2++2OH-
D．H2SO4=2H++SO42-
A、由质量守恒定律及电荷守恒可知，镁离子带2个单位的正电荷，硫酸根离子带2个的单位的负电荷，则MgSO4=Mg2++SO42-，故A错误；
B、碳酸钠在水中电离生成钠离子和碳酸根离子，则电离方程式为Na2CO3=2Na++CO32-，故B正确；
C、氢氧化钡在水中电离生成钡离子和氢氧根离子，则电离方程式为Ba（OH）2=Ba2++2OH-，故C正确；
D、硫酸电离生成氢离子和硫酸根离子，则电离方程式为H2SO4=2H++SO42-，故D正确；
故选A．
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| Gilbert joined the Science Club last summer. One day he was given a piece of paper, a block of wood and four wheels; he was told to go home and 1 them all to his dad. However, Gilbert's mom knew that his dad wasn't good at 2 things and decided that she would read the 3 and let Gilbert do the work. A few days later the block of wood was turning into a car that Gilbert 4 named "Blue Lightning". Then he and his mother went to a car race together. But when they 5 there. Gilbert found that all the other cars were made by "father-son" partnership (合作). The race began. One by one the cars were knocked out until it 6 to the final (决赛) between Gilbert and Jimmy. Just before the race. Gilbert asked 7 they could stop for a minute so that he could make a wish. After a long minute, Gilbert said that he was 8 . People cheered as the race began Jimmy stood with his father and watched their car 9 down the road while Gilbert was surprised at the great 10 of his car as it rushed over the finishing line less than a second 11 Jimmy's. Gilbert jumped up and down with 12 . Soon the club manager came over and asked him,"So, Gilbert,your wish was to 13 , right? " "Oh no, sir," he replied."I just wished that I wouldn't cry if I lost." Children sometimes 14 adults with unexpected ideas. When Gilbert first saw the other cars, he didn't cry out. "Not fair! Other children had their fathers' help!" Gilbert didn't wish for victory in the race; 15 he wished for courage. | ||||
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