What is an abstract in science

Asolution contains 225 g of sodium chloride, nacl, dissolved in enough water to make a 0.25 l of solution. what is the molarity of the solution?

Calculate - analysis of compound composed of iron and oxygen yields 174.86 of fe and 75.14g of o. what is the empirical formula for this compound?

Consider the following reaction at equilibrium: c(s)+h2o(g)⇌co(g)+h2(g) predict whether the reaction will shift left, shift right, or remain unchanged upon each of the following disturbances. a) c is added to the reaction mixture. b) h2ois condensed and removed from the reaction mixture c) co is added to the reaction mixture d) h2 is removed from the reaction mixture.