<?xml version="1.0" encoding="utf-8"?><!DOCTYPE Zthes SYSTEM "http://zthes.z3950.org/xml/zthes-05.dtd">  <Zthes><term><termId>31373639</termId><termName>sodium carbonate</termName><termType>PT</termType><termNote><![CDATA[ An anhydrous grayish-white, odorless, water-soluble powder, NA2CO3, usually obtained by the Solvay process and containing about 1 percent of impurities consisting of sulfates, chlorides, and bicarbonates. It is used in the manufacture of glass, ceramics, soaps, paper, petroleum products, as a cleanser, for bleaching, and in water treatment. ]]></termNote><termCreatedDate>2026-03-30 20:40:45</termCreatedDate><relation><relationType>UF</relationType><termId>31373640</termId><termName>sal soda</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31373641</termId><termName>soda</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31373642</termId><termName>soda ash</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31373643</termId><termName>soda crystal</termName><termType>ND</termType></relation><relation><relationType>UF</relationType><termId>31373644</termId><termName>washing soda</termName><termType>ND</termType></relation><relation><relationType>BT</relationType><termId>31343447</termId><termName>sodium compounds</termName><termType>PT</termType></relation><relation><relationType>NT</relationType><termId>31410816</termId><termName>natron</termName><termType>PT</termType></relation></term>  </Zthes>