A.3                   B.10                       C.5                         D.6

A.+4                       B.+5                       C.+6                      D.+7

A.它們與酸反應(yīng)時(shí)，NaHCO₃產(chǎn)生CO₂速度更快

B.NaHCO₃在加熱時(shí)易分解產(chǎn)生CO₂，而Na₂CO₃不能分解

C.等質(zhì)量的NaHCO₃和NaCO₃，NaHCO₃與酸反應(yīng)產(chǎn)生的CO₂量多

D.NaHCO₃比Na₂CO₃價(jià)格便宜

A.HCl              B.Na₂SO₄              C.FeCl₃               D.CuSO₄

①鉀的火焰顏色要通過藍(lán)色鈷玻璃觀察

②先灼燒鉑絲到火焰無色時(shí)再蘸被檢驗(yàn)物質(zhì)

③每次實(shí)驗(yàn)后要將鉑絲蘸鹽酸灼燒干凈

④實(shí)驗(yàn)時(shí)最好選擇本身顏色較強(qiáng)的火焰

⑤沒有鉑絲可用無銹的鐵絲代替

A.僅③不正確                              B.僅④不正確

C.④⑤不正確                              D.全部正確

A.Li、Na                B.Rb、K                 C.Na、K                  D.Li、K

A.①②③④                  B.②①③④                   C.④②①③                     D.③②①④

A.干冰                    B.鹽酸                        C.碳酸氫鈣                      D.氫氧化鈣

A.PCl₃PCl₅                              B.Mn²⁺

C.SO₂H₂SO₃                           D.NaClHCl

A.Br₂+2KI====2KBr+I₂                         B.Zn+H₂SO₄====ZnSO₄+H₂↑

C.2Al+Fe₂O₃2Fe+Al₂O₃               D.C+H₂OCO+H₂