Which element is most chemically similar to chlorine

Agas at 155 kpa and standard temperature has an initial volume of 1.00 l. the pressure of the gas rises to 500 kpa as the temperature also rises to 135°c. what is the new volume? 2.16 l 0.463 l 0.207 l 4.82 l

What is the percentage of hydrogen in nitrogen trihydride

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)