What is the rate constant of a first-order reaction that takes 490 secondsseconds for the reactant concentration to drop to half of its initial value

What is the molar mass of the anhydrous compound? answer using four significant figures. 36.02 g/mol 120.15 g/mol 156.12 g/mol

You are attempting to recrystallize a crude product mixture. you add the appropriate amount of hot solvent and are allowing the solution to slowly cool to room temperature. however, at room temperature no crystals have appeared, which of the following methods should be used to induce crystallization? choose all correct answers. a) place the flask in an ice bath. b) swirl the contents of the flask. c) add a small seed crystal of the desired product. d) scratch the inside of the glassware using a stir rod. it can be multiple choices

Which of the following notations would be the appropriate and final way to display the formula for magnesium chloride a. mgcl2 b. mg+2cl–1 c. mgcl2 d. mgcl