Pls guys help me solve this 2.4dm^3 of oxygen gas

Avariable that is not being directly tested during an experiment should be

How many liters of 3.0 m naoh solution will react with 0.60 liters of 4.0 m h2so4? h2so4 + naoh → na2so4 + h2o 1.2 l 1.6 l 2.4 l 2.8 l

Which of the following observations indicates that an atom has neutrons? some uncharged particles are scattered by a beryllium atom when it hits a gold foil. some uncharged particles bounce back from a gold foil when it is bombarded with alpha particles. a radiation consisting of uncharged particles is emitted when alpha particles strike beryllium atoms. a radiation which attracts electrons is produced when a beryllium atom is bombarded with alpha particles.