Does adding salt to pasta make it cook faster

An alloy contains 66 g of pure zinc. what is the percentage of zinc in the alloy? express your answer to two significant figures and include the appropriate units.

How many moles are in 43.9 l of oxygen

The activation energy for the reaction no2(g)+co2(g)⟶no(g)+co(g) is ea = 300 kj/mol and the change in enthalpy for the reaction is δh = -100 kj/mol . what is the activation energy for the reverse reaction?