21. which of the equations is balanced? a) 2li2o + h2o ⇒ 2lioh b) 3fe + 3o2 ⇒ 2fe2o3 c) 2n2 + o2 ⇒ 3n2o d) 3mg + n2 ⇒ mg3n2

The vapour pressure of benzene is 53.3 kpa at 60.6 °c, but it fell to 51.5 kpa when 19.0 g of a non-volatile organic compound was dissolved in 500 g of benzene. calculate the molar mass of the compound.

Which statement is the best definition of an atom? a) anything that has mass and occupies space. b) the smallest particle that has the properties of an element. c) a substance that cannot be broken down chemically into simpler substances. eliminate d) the smallest unit of a substance that exhibits all of the properties characteristic of that substance.

Examples of states of consciousness include a. daydreaming b. dreaming during sleep c. hypnosis d. all of the above