设xg氢氧化钠参加反应,生成yg碳酸钠:
2NaOH + CO2 = Na2CO3 + H2O
80 44 106
xg 11g yg
80/xg = 44/11g = 106/yg
x= 20 y=26.5
w(Na2CO3) = 26.5g/( 20g/4% + 11g) * 100% =5.2%
选A
2NaOH+CO2=Na2CO3+H20
80 44 106
20g 11g 26.5g
M=20g/4%=500g
w=26.5/(500g+11g)*100%=5.19%