欲配制100ml 1.0 mol/L Na2SO4溶液，正确的方法是
① 将14.2 g Na2SO4 溶于100ml水中
② 将32.2g Na2SO4·10H2O溶于少量水中，再用水稀释至100 ml
③ 将20 ml 5.0 mol/L Na2SO4溶液用水稀释至100 ml
| A．①② | B．②③ | C．①③ | D．①②③ |
相关试题
Charles was alone at home, with_______ looking after him.
| A．someone | B．anyone | C．not one | D．no one |
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| A．said | B．to say | C．saying | D．being said |
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| A．can | B．must | C．will | D．may |
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—— ______ , as a matter of fact
| A．Go ahead | B．Yes, my pleasure |
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