How many liters of a 3.89 M K2SO4 solution are needed to provide 99.8 g of K2SO4 (molar mass 174.01 g/mol)

Iknow #2 is d. i just need to know why

How many electrons does silver have to give up in order to achieve a sido noble gas electron configuration?

In november 1987, a massive iceberg broke loose from the antartic ice mass and floated free in the ocean. the chunk of ice was estimated to be 98 mi long, 25 mi wide, and 750 ft thick. a typical backyard swimming pool contains about 24,000 gallons of water. how many of these pools could you fill from the water in this iceberg? (assume the iceberg is a rectangular solid of the above dimensions and consists of water only). express answer in scientific notation.