A 0.25 g sample of a pretzel is burned. The heat gives off is used to heat 50. G of water from 18 C to 42 C. What is the beefy value of the pretzel in kcal/g?

How does the principle of electromagnetism explain the interaction between earth’s magnetic field and the solar wind?

Acontrol during an experiment. might change remains constant does not exist does change

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.