This study analysed the distribution of questions from the gas law chapters of four high school and four college chemistry textbooks based on six variables-Book Type (secondary versus introductory college), Cognitive Skill (lower-order versus higher-order), Question Format (calculation versus multiple-choiceversus short-answer), Question Placement (in-chapter versus end-of-chapter versus test-bank), Question Type (qualitative versus quantitative), and Representation (macroscopic versus particulate versus symbolic).The questions in these chapters were homogeneously distributed for the Cognitive Skill and the Representation variables, but showed differences in question distribution based on the Book Type, Question Format, Question Placement, and Question Type variables. The loglinear analysis method used in this study provides one way to analyse the distribution of different types of questions appearing in chemistry textbooks, and these differences in question distribution can be helpful for textbook authors to evaluate the types of questions appearing in their textbooks and how they are presented, and can be helpful for chemistry instructors to determine how they need to adapt their instructional lessons to prepare students for course examinations or college/career placement examinations.

The dichloromethanesulfonates of silver and other +1-charged cations, M + (Cl 2 CHSO − 3 ) (M = Ag, Tl, Li, Na, K, Rb, Cs) were synthesized and studied by 35 Cl NQR. Dichloromethanesulfonic acid was prepared by the methanolysis of dichloromethanesulfonyl chloride, and was then neutralized with the carbonates of the +1-charged cations to produce the corresponding dichloromethanesulfonate salt. This NQR study completed the investigation of the chloroacetates and chloromethanesulfonates of silver, Ag + (Cl x CH 3−x SO − 3 ) and Ag + (Cl x CH 3−x CO − 2 ), and suggests (1) that the ability of organochlorine atoms to coordinate to silver decreases as the number of electron-withdrawing groups (Cl, SO − 3 , CO − 2 ) attached to the carbon atom increases; (2) that the unusually large NQR spectral width found among M + (Cl 2 CHCO − 2 ) salts is not present among M + (Cl 2 CHSO − 3 ) salts, and therefore is not generally characteristic of the dichloromethyl group in salts.

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