Multiple bond is a fundamental concept of chemical bond. The maximum number of chemical bond between main group elements in the periodic table is three. Stable double and triple bond between light main elements such as carbon, nitrogen and oxygen can be formed, while multiple bonds between heavy main elements is unstable due to Pauli repulsion. Afterward, scientists synthesized homoleptic and heteroleptic double bond compounds involving heavier p block elements. However, it is difficult to form triple bond between heavier p block elements because of their high reactivity. Recently, stable disilyne with silicon-silicon triple bond was synthesized, isolated and characterized. Quadruple, quintuple and sextuple bond were found by experimental and theoretical study on interactions between transition metals, because of d and f orbital involved in bond. Sextuple bond can be formed between two same actinide atoms.

Course contents of general chemistry for international students in petroleum engineering major were selected and designed based on the original English textbooks, the characteristics of petroleum engineering and the actual situation of teaching. So, the contents accorded with acceptable level of students and met requirements of chemical knowledge in petroleum engineering major. Moreover, teaching proceeded in proper sequence combining examples and extended contents related to petroleum engineering fields, in order to help students to understand the close relationship between chemistry and petroleum engineering.

There are many complicated and confusing formulae in physical chemistry, especially in chemical thermodynamics, which make students feel overburdened. This paper introduces some simple skills of memorizing formulae of chemical thermodynamics，methods of analyzing solid-liquid phase diagrams，and strategies of solving physical chemistry problems with an example of calculation of entropy change.

Some feasible teaching methods are given with cases, including grasp the characteristics of organic chemistry, explain examples in detail, simplify complex problems, teach assisted by multimedia, guide students to learn independently, and summarize teaching contents, in order to solve current problems in organic chemistry teaching and improve teaching effectiveness.

Teaching contents, teaching methods and assessment mode of chemistry of fine chemicals were explored, including selected reasonable teaching materials, used various teaching methods, changed assessment mode and adjusted experimental contents, in order to inspire learning interests of students, guide students to learn actively, pay attention to learning process, and strengthen innovative and practical ability of students.

Teaching by case analysis is benefit to train the observing and thinking ability of students. Questions are designed based on self-made hydrogen balloon, in order to guide students to analyze from many aspects such as security, quantity, control of reaction rate and engineering process.

A Brnsted acidic deep eutectic mixture was prepared by choline chloride and p-toluenesulfonic acid, and its catalytic activity in the one pot synthesis of 2,4,5-trisubstituted imidazoles was studied. The Experiments showed that the new deep eutectic mixture has simple preparation method, excellent catalytic activity, simple treatment after reaction, and good reusability. Moreover, the possible reaction mechanism was discussed. The experiments meet the demands of green chemistry; involves organic chemistry, analytical chemistry and experimental operation skills such as extraction, determination of melting point and recrystallization; and have significant features of comprehensive chemical experiment.

The comprehensive physical chemistry experiment of "preparation of polyvinyl alcohol and determination of its molecular chain linkage" was studied. The best preparation scheme of polyvinyl acetate (PVAc) was obtained, and polyvinyl alcohol (PVA) was produced by alcoholysis of PVAc. The molecular weight of the PVA and its product which decomposed by periodate were determined by viscosity method, then the ratio of the head-to-tail linkage and the head-to-head linkage of PVA molecular chain was calculated.

Training of college students' innovative ability of science and technology is the core of teaching reform of higher education. New teaching mode of physical chemistry experiment was constructed from textbook, teaching contents and teaching process, integrating basic experimental operation and scientific research, in order to improve sci-tech innovative ability of college students.