From the related question (see below) it can be seen that for butter 1 fluid ounce has a mass of 1 ounce. So (50 grams) / (28.35 grams/oz) = 1.76 oz, which for butter is 1.76 fluid ounces.
One fluid ounce of melted butter is equivalent to one fluid ounce by volume.
50g = 1.764 oz
1 fl oz
33.8 fl oz + 16.9 fl oz = 50.7 fl oz.
2.5360517 fl oz.
Approximately 7 fl oz
32 fl oz = 946.353mL
16 fl oz is 473.176mL
1 cup = 8 fl oz 2 cups = 16 fl oz 3 cups = 24 fl oz That's not quite as much as 26 fl oz.
7 fl oz (UK) = 199 millilitres. 7 fl oz (US) = 207 ml.
5 fl oz = 142.1 millilitres (approx).
That is 4 fl oz.