A researcher is trying to identify whether household substances are basic. Which approach would BEST help the researcher investigate whether substances are basic?
O A. Mix each substance with a weak base and record the results.
OB. Test each substance with red litmus paper.
O C. Observe each substance and record its color.
OD Test each substance with blue litmus paper.

Answer earth,water,fire and air;

Reaction involved in present system is :   c12h22o11 + h2o → 2 c6h12o6the reaction system is obeying following rate law:   rate = k[c12h22o11]thus, it is a first order reaction.now, for 1st order reactionrate constant (k) =  given: initial conc. = 3.0 g, final conc. = 2.7 g, t = 2.5 h∴rate constant (k) =  ∴ k = 0.04215 h-1now, for 1st order reaction, half life = 0.693/k = 0.693/0.04215 = 16.4 hthus correct answer is option b