<span>4 Ca+10 HNO3=N2O+4 Ca(NO3)2+5 H2O</span>
<span> 0 </span><span>+2</span>
<span>Са </span><span> -</span><span>2е --> Ca---4-восстановитель</span>
<span> +5 </span><span>+1</span>
<span>N + 4e --> N ----2 - окислитель
</span>
<span><span>
</span></span>
<span><span>
</span></span>