Put the cap on the blender

Hello, could you help me with these cooking expressions?

Is this correct? The sentences are within a recipe context:



a)"Peel and slice the banana without unfreezing it".



b) Make sure the ingredients don´t become unfrozen.



c) Blend them FOR 5 minutes (I think this one is right)



d) Put the cap on the blender because if not the mix will get out. (this one does not sound natural, but the person has pre intermediate level). How should he have written?



e) "Put the blender at a maximum speed for five minutes" Does this sound correct? I think so.



f) "When you serve the strawberry smoothie, you can put ice into it". It does not sound idiomatic to me. But is it grammatically correct?



g) Can we use the word "mixture" when we are only referring to liquids?



Thank you!