Cho 10,2 gam hỗn hợp A gồm Mg và Al phản ứng vừa đủ với dung dịch H2SO4 19,6%, sau phản ứng thu được 11,2 lit H2( đktc) a. Tính % khối lượng mỗi kim loại trong A.
b. Tính khối lượng dung dịch H2SO4 cần dùng.

Why do the strengths of london (dispersion) forces generally increase with increasing molecular size? choose one: a. heavier atoms have stronger attractions for each other than lighter atoms. b. dispersion forces are all equal in magnitude; there is no size dependence. c. dispersion forces arise from the attraction between the nuclei of atoms, and larger molecules have larger nuclei. d. dispersion forces arise from dipoles caused by the electron distribution being distorted. larger molecules have more electrons and, therefore, more distortions and a bigger force. e. dispersion forces depend on distance. larger molecules are farther apart and so the forces are smaller.

Why is it important for scientists to review and repeat the work of other scientists? 1.a scientific theory must be tested three times before it is proven. 2.the scientific method only applies to repeated experiments. 3.an experiment may have had errors that the scientists didn't recognize. 4.the results of individual scientists may be influenced by bias. 5.an experiment must be performed twice before the data can be analyzed.

Rank the compounds below from slowest to fastest rate of hydration. 1) formaldehyde 2) 3,3-dimethyibutan-2-one 3) propanal 4)3-methylbutan-2-one 5) butan-2-one