for which of the following reactions is δh∘rxn equal to δh∘f of the product(s)?you do not need to look up any values to answer this question.

Students at community colleges generally enjoy which of the following benefits? a. availability of lots of on-campus housingb. high tuitionc. selectivity in the admissions processd. fleible class schedules

Did the universe cool off or get hotter as it expanded after the 'big bang"?

Two technicians are discussing how to test a car's exhaust by holding a small piece of paper within an inch of the tailpipe mouth. technician a says that if the paper is vibrating due to a "puffing" output from the tailpipe, this signals a smoothly running engine. technician b says that if the paper is being drawn toward the tailpipe, this could indicate burned exhaust valves. who is correct? a. technician b b. both technicians a and b c. technician a d. neither technicians a or b