Convert from mace [China] to arroba [Spain]

Unit Definition (mace [China])
The mace is a traditional Chinese unit for weighing precious metals, especially silver. In the European colonial period, the mace was considered equal to 0.1 tael or liang; this would be 2/15 ounce or about 3.78 grams.

Unit Definition (arroba [Spain])
The arroba [Spain] is a traditional unit of weight in Spain and Portugal, equal to 1/4 quintal. However, the Spanish and Portuguese quintals are of different sizes. In Spain, the arroba equals 25.36 pounds (11.50 kilograms); arrobas of very similar sizes were established in the Spanish speaking countries of Latin America. The arroba has also been used as a metric unit equal to exactly 15 kilograms. The name of the unit comes from ar rub', Arabic for "the quarter."