If the same amount of solid sodium (na) is used in each reaction, which shape will increase the reaction rate the most?

a. the reaction rate is highest when 2 cm2 blocks of sodium are used.
b. the reaction rate is highest when sodium powder is used.
c. the reaction rate is highest when 3 cm2 blocks of sodium are used.
d. the reaction rate is highest when strips of sodium are used.

(B.) The reaction rate is highest when sodium powder is used.

Explanation:

Five factors that affect the rate of reactions are : Temperature, concentration, nature of catalyst, chemical nature of reactants and  nature of subdivision of particles (heavier size versus smaller or powdered particles).

Nature of subdivision of particles :

Since reactions occur at the boundary between two phases therefore tyhe rate of reaction depends on surface contact available between them. A powdered particle has generally more surface area than the particle in solid form.

Water boils when the vapor pressure of the water equals the atmospheric pressure that's pressing down on it.  Water boils at a lower temperature (more easily) at higher elevations (like on mountains), because:

-  Atmospheric pressure is lower at higher elevation

-  Easier for vapor pressure to equal this lower atmospheric pressure

Since the water boils at a lower temperature, it takes longer for the pasta to cook.