Indicates alkalinity using single container and makes a call from this (5-3)
I believe the answer is:
phone-box
'indicates alkalinity using single' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'container and makes a call from this' is the wordplay.
I cannot really see how this works, but
'container' could be 'box' (box is a kind of container) and 'box' is located in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is present in the answer.
'call' could be 'ho' (historical exclamation used to attract attention) and 'ho' is present in the answer.
'from' could be 'e' (I've seen this in other clues) and 'e' is located in the answer.
A single letter 'p' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for phone-box that I've seen before include "Booth from which to make calls" , "Booth for callers, red in the UK" , "Vital pre-mobile communications facility?" , "Booth for making calls" .)