<span>1 2 3 4
CH3-CH2-C≡CН
это бутин-3</span>
<span> Al2o3 Al2(+3) o3(-2)</span>
<span><span>Li2Se Li2(+1) Se(-2)</span></span>
<span><span><span>Mgbr2 Mg(+2) Br2(-1)</span></span></span>
<span><span><span><span>SF6 S(+6) F6(-1)</span></span></span></span>
<span><span><span><span><span>HRO3 H(+1) R(+5) O3(-2)</span></span></span></span></span>
<span><span><span><span><span><span>H2CO3 H2(+1) C(+4) O3(-2)</span></span></span></span></span></span>
<span><span><span><span><span><span><span>KNO3 K(+1) N(+5) O3(-2)</span></span></span></span></span></span></span>
Массовая доля фосфора равна 62/142*100%=43.66%
3) 43,7%
<span>P</span>⁺³<span>Cl3</span>⁻¹<span>,P2</span>⁺⁵<span>O5</span>⁻²<span>,Ca3</span>⁺²<span>P2</span>⁻³<span>,Na3</span>⁺¹<span>P</span>⁻³
AlCl3 + 3NaOH = Al(OH)3 + 3NaCl