Trộn hai thể tích bằng nhau của dung dịch NH4OH 0,10M với dung dịch NH4Cl 0,10M. Hãy tính pH của dung dịch đệm thu được. Biết pKb(NH3) = 4,75.

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.

The chemical bond connecting one nucleotide with the next one along the nucleic acid chain is called a

Astudent is trying to create a table that compares hypotheses, theories, and laws. hypothesis theory law do scientific researchers formulate it? yes yes yes does it explain why things happen? yes yes no yes yes yes is it used to make predictions? no yes yes which of the following questions would most likely fill the blank in the table? is it an intelligent guess? is it newly formulated? is it based on observations? has it been proved?