1) Дано:
<span>m</span>(<span>H</span><span>₂</span>) = 6 г
<span>m</span>(<span>Cl</span><span>₂</span><span>) = 7.1 </span>г
Найти:
<span> </span><span>m(HCl)-</span>?
<span>V(HCl)</span>-?
Решение:
6 г<span> </span><span> </span><span> </span><span> </span><span> </span><span> </span>7,1 г<span> </span><span>x </span>г
<span>H</span><span>₂<span> </span><span> </span><span> </span></span><span> </span>+<span> </span><span> </span><span> </span><span>Cl</span><span>₂</span> =(при <span>hv</span>)= 2<span>HCl</span>
2 г/моль <span> </span>71 г/моль<span> </span>2<span>•</span> 36,5 г/моль
6/2<span> </span>7,1/71
3 > 0,1<span> </span>значит, считаем <span> </span>по <span>Cl</span>.
<span>X</span>= 2<span>•</span>36,5 <span>•</span> 7,1 / 71 = 7,3 г
<span>V</span>=<span>n</span><span>•</span><span>Vm</span> = <span>m</span>/<span>M</span><span>•</span> <span>Vm</span> = 7.3/36.5 <span>•</span> 22.4 = 4.48
Ответ: <span>m</span>(<span>HCl</span>) = 7.3 г; <span>V</span>(<span>HCl</span>) = 4.48 дм<span>³</span>
<span> </span>
2)Дано:
<span>m</span>(<span>Mg</span>) = 48 г
<span>V</span>(<span>O</span><span>₂</span>) = 11.<span>4</span>дм<span>³</span>
<span> </span>
Найти:
<span> </span><span>m</span>(<span>MgO</span>)-?
Решение:
48 г<span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span>11.4 дм<span>³</span><span> </span><span>x</span>г
2<span>Mg</span><span><span> </span><span> </span><span> </span></span><span> </span>+<span> </span><span> </span><span> </span><span>O</span><span>₂</span> <span> </span>=(при <span>t</span>)=<span> </span><span> </span>2<span>MgO</span>
2<span>•</span>24г/моль <span> </span>22,4дм<span>³</span>/моль<span> </span>2<span>•</span> 40 г/моль
48/2<span>•</span>24<span> </span><span> </span>11,4/22,4
1 > 0,509<span> </span>значит, считаем <span> </span>по <span>O</span><span>₂</span>.
<span>X</span>= 2<span>•</span>40 <span>•</span> 11.4 / 22.4 = 40.7 г
Ответ: <span>m</span>(<span>MgO</span>) = 40.7 г
3)Дано:
<span>m</span>(<span>NaOH</span>) = 120 г
<span>m</span>(<span>ZnCl</span><span>₂</span>) = 1<span>36 </span>г
Найти:
<span> </span><span>m</span>(<span>Zn(OH)</span><span>₂</span>)-?
Решение:
120 г<span> </span><span> </span><span> </span><span> </span><span> </span><span> </span><span> </span>136 г<span> </span><span> </span><span> </span><span> </span><span>x</span>г
2<span>NaOH</span><span><span> </span><span> </span><span> </span></span><span> </span>+<span> </span><span> </span><span> </span><span>ZnCl</span><span>₂</span> <span> </span><span> </span>=<span> </span><span> </span>2<span>NaCl</span> + <span>Zn</span>(<span>OH</span>)<span>₂</span>
2<span>•</span>40г/моль <span> </span>136 г/моль<span> </span><span> </span><span> </span><span> </span><span> </span>99 г/моль
120/2<span>•</span>40<span> </span><span> </span>136/136
1,5 > 1<span> </span>значит, считаем <span> </span>по <span>ZnCl</span><span>₂</span>.
<span>X</span>= 99<span>•</span> 136/ 136 = 99 г
Ответ: <span>m</span>(<span>Zn</span>(<span>OH</span>)<span>₂</span>) = 99 г