Nonpolar and small polar molecules can pass through the cell membrane, so they diffuse across it in response to concentration gradients. Carbon dioxide and oxygen are two molecules that undergo this simple diffusion through the membrane. The simple diffusion of water is known as osmosis.
Answer:
in both nucleophil attach the c and leaving group leave but in acyl nu. subsituation c of carbonyl because of double bond with o have bigger positive charge and is better electrophil so do it faster,also alkyl nu. subsituation can have rearangment if going from sn1 and in sn2 sterichemistry of molecule change , acyl nu. subsituation most of time is better
SAMPLE A - <span>pure substance.
</span>SAMPLE B - <span>homogeneous mixture.
</span>SAMPLE C - <span>heterogeneous mixture.
</span>Pure substance - <span>constant composition and properties.</span>
Homogeneous mixture - same uniform appearance and composition.
Heterogeneous mixture - <span>not </span>uniform<span> in composition, two phases (liquid and dust).
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