Which statement describes a reversible reaction at equilibrium?
(1) the activation energy of the forward reaction must equal the activation energy of the reverse reaction.
(2) the rate of the forward reaction must equal the rate of the reverse reaction.
(3) the concentration of the reactants must equal the concentration of the products.
(4) the potential energy of the reactants must equal the potential energy of the products.

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?

Alice did an experiment to find the relationship between the angle at which a ray of light strikes a mirror and the angle at which the mirror reflects the light. she placed a ray box in front of a mirror. she changed the angle at which the light from the ray box struck the mirror and noted the corresponding angle at which the mirror reflected the light. which of the following is the dependent variable in this experiment? the mirror used to reflect the light the ray box used as the source of light angle at which the light from the ray box strikes the mirror angle at which the mirror reflects the light from the ray box