Does salt water or fresh water freeze faster

What is true for a substance that releases energy

Pl what kind of reaction is this? nahco3 + h2o → co2 + naoh + h2o -composition -decomposition -single replacement -double replacement im leaning more toward single replacement. if im wrong can you explain whyy?

Due tomorrow which would have a lower ph, a 0.1 m solution of a strong base or a weak base? why? which would have a higher ph, a 0.1 m solution of a strong base or a weak base? why?