Răspuns:
M,Na3BO3=128g/mol
M,NaOH= 40g/mol
M, B=11g/mol
2mol......6mol.........2mol
2B + 6NaOH---> 2Na3Bo3 + 3H2
2x11g......6x40g..........2x128g
33g............x....................y
x=360gNaOH======> niu=m/M=360/40mol=9mol NaOH
y=384gNa3BO3
Explicație: