What is the effect of impurities on the melting point of a compound

How many grams of naoh are needed to make 0.250 liter of a 0.500 m solution of naoh? 0.125 g 5.00 g 2.00 g

For the following dehydrohalogenation (e2) reaction, draw the zaitsev product(s) resulting from elimination involving c3–c4 (i.e., the carbon atoms depicted with stereobonds). show the product stereochemistry clearly. if there is more than one organic product, both products may be drawn in the same box. ignore elimination involving c3 or c4 and any carbon atom other than c4 or c3.

Determine the percent sulfuric acid by mass of a 1.61 m aqueous solution of h2so4. %