UC知道求助 快快！！！
来源：百度知道 编辑：UC知道 时间：2024/05/13 08:53:34
analysis of data
what physical properties do all the substances share
make a data table showing all you observation
for each observation-classify if it is a physical or chemical change that took place.
which substances are soluble in water?
which substances are reactive with vinegar? how do you know?
which substances are reactive with iodine? how do you know?
材料有：（发酵粉,小苏打，糖，水，醋，碘）
发酵粉加水
发酵粉加醋
发酵粉加碘
小苏打加水
小苏打加醋
小苏打加碘
糖加水
糖加醋
糖加碘
what physical properties do all the substances share
make a data table showing all you observation
for each observation-classify if it is a physical or chemical change that took place.
which substances are soluble in water?
which substances are reactive with vinegar? how do you know?
which substances are reactive with iodine? how do you know?
材料有：（发酵粉,小苏打，糖，水，醋，碘）
发酵粉加水
发酵粉加醋
发酵粉加碘
小苏打加水
小苏打加醋
小苏打加碘
糖加水
糖加醋
糖加碘
物理变化
要想和葡萄糖反应生成楼上所谓的“酯”，不可能！要是醋酸酐还可以。但这不叫酯，叫糖苷。
糖加上醋是物理变化而已，不到化学反应条件。
但我还有一点，糖会在酸性条件下，由环状变为链状结构，存在性质改变了，也就是酸催化了缩醛水解了。但我不知是否要叫化学变化，但要勉强地说也不为错。
发酵粉加水 物理，发酵粉加醋 物理，发酵粉加碘，化学。
小苏打加水 物理，小苏打加醋 化学，小苏打加碘 化学。
糖加水 物理，糖加醋物理， 糖加碘，物理