Which of the following is the correct conversion of 25.0 grams of NaCl to moles? (Molar mass of NaCl = 58.44 g/mol)

For 7 hours, an intravenous bag delivers medication to a patient at a rate of 2.75 drops a second with a mass of 42 mg per drop. Identify the given amount and all conversion factors.

During World War II in the US, nickel metal was in short supply and needed for the war effort. So from 1942 to 1945 the government replaced the nickel in the five-cent coin with silver until it was 35 grams of silver per 100 grams. Today the mass of the coin is 5.0 grams with a value of approximately \$28.40 per ounce. Identify the given amount and all the conversion factors from the presented information.