i think YES, -ve value of delta G of system is equal to d amount of non expansion work done on d system. der4 -ve value of delta G indicates electrical work done on d system by d surrounding.

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when delta g is negative,it means that the reaction is spontaneous i.e it takes place by itself without the help of an external agent e.g. a hot cup of tea when kept at room temp. becomes relatively cooler after some time.this reaction is spontaneous.so,according to me no work is done by the surroundings!!!!!!!!