Speed and velocity is a scalar and vector quantity of a similar parameter, respectively. They both refer to how fast an object moves. However, the speed only has to do with the magnitude. The velocity takes into account the sign which indicates the direction of the movement. For example, the value is -5 m/s. The speed is 5 m/s, but the velocity is 5 m/s moving downwards because the negative sign denotes downward movement or movement to the left.
The balanced equation for the reaction is ;
2Zn + O2 —> 2ZnO
The stoichiometry of O2 to ZnO is 1:2
The mass of ZnO formed - 358.5 g
The number of moles formed - 358.5 g / 81.4 g/mol = 4.4 moles
Therefore number of O2 moles reacted = 4.4 moles /2 = 2.2 mol
Mass of O2 reacted = 2.2 mol x 32 g/mol = 70.4 g
A is the correct awnser Beacuse it ether right kne