下列物质的利用中，只与物理性质有关的是（ ）
A．制作蛋糕时加小苏打
B．食盐作调味剂
C．熟石灰改良酸性土壤
D．一氧化碳作还原剂
A、制作蛋糕时加小苏打（碳酸氢钠的俗称），是利用了碳酸氢钠能与发酵产生的酸反应生成二氧化碳，受热分解生成二氧化碳气体，需要通过化学变化才表现出来，是利用了其化学性质，故选项错误．
B、食盐作调味剂，不需要发生化学变化就能表现出来，是利用了其物理性质，故选项正确．
C、熟石灰改良酸性土壤，是利用了熟石灰能与酸性土壤中的酸反应的性质，需要通过化学变化才表现出来，是利用了其化学性质，故选项错误．
D、一氧化碳作还原剂，需要通过化学变化才表现出来，是利用了其化学性质，故选项错误．
故选B．
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