A student test two solvents (A and B) for purification an impure organic compound. It is found that the compound has low solubility in both of solvents at low temperature and soluble at boiling point. If solvent A has a lower vapor pressure compare to B. Then:

Which of the following would be an accurate picture of the earth during the summer time of the northern hemisphere?

7. in the cycle, a virus integrates its dna into the host's dna, and its dna is replicated when the host dna is replicated. a. infectious b. retroviral c. lysogenic d.lytic

Ammonium perchlorate nh4clo4 is the solid rocket fuel used by the u.s. space shuttle. it reacts with itself to produce nitrogen gas n2 , chlorine gas cl2 , oxygen gas o2 , water h2o , and a great deal of energy. what mass of nitrogen gas is produced by the reaction of 2.1g of ammonium perchlorate?