A sample of He collected over water at a temperature of 20C has a pressure of 705 torr. What is the pressure of the dry gas? The vapor pressure of water at 20 degrees * C is 17.5 torr.

The pressure of the dry gas : 687.5 torr

Dalton's law of partial pressures states that the total pressure of a mixture of gases is equal to the sum of the partial pressures of the component gases  

Can be formulated:  

P tot = P1 + P2 + P3 ....  

The partial pressure is the pressure of each gas in a mixture  

Since the gas mixture consists of He and H₂O :

P tot=P He + P H₂O

i think that the answer is c

answer: any goods being imported from another country may be subject to issued by the federal government are tariffs

explanation:  

tariffs are a tax on anything that are imported from abroad. government use them to protect and boost their local industries and the thought is that they encourage consumers to buy local instead of importing and they will hope will protect jobs and economy in the country that implements them