Cân bằng các phương trình hóa học sau:
\(CO_2+CaOH_2->CaCO_3+H_2O\)
\(BaCl_2+H_2SO_4->BaSO_4+HCl\)
\(KMnO_4+HCl->KCl+MnCl_2+Cl+H_2O\)
\(Fe_3O_4+HCl->FeCL_2+FeCl_3+H_2O\)
\(Na+O_2->Na_2O\)
\(NaHCO_3+NaOH->Na_2CO_3+H_2O\)
\(NaHCO_3+Ca\left(OH\right)_2->CaCO_3+Na_2CO_3+H_2O\)
\(K_3PO_4+Ca\left(OH\right)_2->KOH+Ca_3\left(PO_4\right)_2\)
Cân bằng các phương trình hoa học sau:
\(Al+HSO_4->Al_2\left(SO_4\right)_3+SO_2+H_2O\)
\(CaCO_3->CaO_2+CO_2\)
\(AlOH_3->Al_2O_3+H_2O\)
\(Cu+HNO_3->Cu\left(NO_3\right)_2+NO+H_2O\)
\(P+O_2->P_2O_5\)
\(AlOH_3+H_2SO_4->Al_2\left(SO_4\right)_3+H_2O\)
\(AlCl_3+BaOH_2->AlOH_3+BaCl_2\)
\(Na_3PO_4+CaCl_2->NaCl+Ca_3\left(PO_4\right)_2\)
IV, Comeplete the verbs in the simple past tense
Snow White was the daughter of a beautiful queen, who died when the girl (be).......... younf. Her father(get married).......... again, but the girl's stepmother was very jealous of her because she was so beautiful. The evil queen (order)..........a hunter to kill Snow White but he couldn't do it because she was so lovely. He (chase)........... her away instead, and she(take)........... refuge with seven dwarfs in their house in the forest
III, Choose the verbs and complete the sentenses:
teach cook want spend ring be sleep study go write
1, She..... out with her boyfriend last night
2, Laura...........a meal yesterday afternoon
3, Mozart.........more than 600 pieces of music
4, I....... tired when I came home
5, The bed was very comfortable so they.........very well
6,Jamie passed the exam because he..... very hard
7, My father...... the teenagers to drive when he was alive
8, Dave...........to make a fire but there was no wood
9, The little boy..............hours in his room making his toys
10,The telephone..........sevesal times and then stopped before I could answer it