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+    <title>Hydrogen Sulphide</title>
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+    <script src="timer.js" defer></script>
+    <meta name="Keywords" content="exercises,  balancing,  chemistry, equations, hydrogen-chloride, ammonia, nitric-acid, nitrates, sulphur-dioxide, hydrogen-sulphide, sodium-hydroxide, sulphuric-acid, preparation ">
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+<tr>
+<td><a href="index.html">Home Page</a></td>
+<td><a href="equ.html">Elementary Equations</a></td>
+<td><a href="advanced.html">Advanced Equations</a></td>
+<td><a href="assorted.html">Assorted Equations</a></td>
+<td><a href="chlorine.html">Chlorine</a></td>
+<td><a href="ammonia.html">Ammonia</a></td>
+</tr>
+<tr>
+<td><a href="nitric-acid.html">Nitric Acid</a></td>	
+<td><a href="sulphur-dioxide.html">Sulphur Dioxide</a></td>
+<td><a href="hydrogen-chloride.html">Hydrogen Chloride</a></td>
+<td><a href="sulphuric-acid.html">Sulphuric Acid</a></td>
+<td><a href="sodium-hydroxide.html">Sodium Hydroxide</a></td>
+<td></td>
+</tr>
+</table>
+<h1 style="text-align:center;">Hydrogen Sulphide</h1>
+
+<h2>Practise balancing equations: </h2> <h3>Direction:</h3> <ul><li>In  the following equations you will see a blank box before the symbol of each compound and element. Enter the lowest possible number in each box, or leave the box blank if you think the chemical needn't have a number (i.e. the number is equivalent to '1').</li> 
+<li>When you think the equation is balanced, click on the small button <span style= "color:blue;"><b>"Check answer"</b></span> that appears below it.</li> <lI>If your equation is incorrect, then click the button <span style= "color:blue;"><b> "Reset"</b></span> and try balancing the  equation again.</li> <li>In case you are in a hurry or are unable to balance, then click the button <span style= "color:blue;"><b>"Show answer."</b></span></li>
+  <li>If you want to know the time taken (minutes:seconds) to balance a chemical equation, you click the <span style="color:blue;"><b>"Start"</b></span> button and after balancing the equation, click the <span style="color:blue;"><b>"Stop"</b></span>button. Once, you have noted the time, click the <span style="color:blue;"><b>"Reset Timer"</b></span> button.
+  </li></ul>
+ 
+<h3>Note:</h3> If you get no response after 
+clicking 'Check answer' or 'Show answer', your browser has disabled to run this 
+program. Enable it by clicking below the 'address 
+bar' and follow the instructions.
+<form name="equations">
+
+  <h4>Preparation of Hydrogen Sulphide:</h4>
+  1. When Iron (II)Sulphide is reacted with dilute Hydrochloric acid, Hydrogen sulphide gas is formed: 
+  <p style="font-size:115%; text-align:center;"><input style="font-size: 16px; text-align: center;" 
+  size=1 name=q1a> FeS + <input style="font-size: 16px; text-align:center;" size=1 name=q1b> HCl &#8594; <input style="font-size: 16px; text-align: center;" size=1 name=q1c> FeCl<sub>2</sub>+ <input style="font-size:16px;text-align:center" size=1 name=q1d> H<sub>2</sub>S</p> 
+ <p style="font-size:115%; text-align:center;">    
+<input onclick="check(1,'Preparation of Hydrogen sulphide',1,2,1,1,0,0,'FeS + HCl','FeCl<sub>2</sub> + H<sub>2</sub>S');" type="button" value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">  &nbsp;&nbsp;&nbsp; <input onclick="show(1,'Preparation of Hydrogen sulphide',1,2,1,1,0,0,'FeS + 2HCl','FeCl<sub>2</sub> + H<sub>2</sub>S');" type="button" value="Show answer"></p>
+<p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer1">00:00</span>
+  <button type="button" onclick="startTimer('timer1')">Start</button>
+  <button type="button" onclick="stopTimer('timer1')">Stop</button>
+  <button type="button" onclick="resetTimer('timer1')">Reset Timer</button>
+ </p>
+<p></p>
+2. When Iron (II)Sulphide is reacted with dilute Sulphuric acid, Hydrogen sulphide gas is formed: 
+  
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q2a> FeS + <input style="font-size: 16px; text-align:center;" size=1 name=q2b> H<sub>2</sub>SO<sub>4</sub>&#8594; <input style="font-size: 16px; text-align: center;" size=1 name=q2c> FeSO<sub>4</sub>+ <input style="font-size:16px;text-align:center," size=1 name=q2d> H<sub>2</sub>S</p> 
+  <p style="font-size:115%; text-align:center;">
+<input onclick="check(2,'Preparation of Hydrogen sulphide',1,1,1,1,0,0,'FeS + H<sub>2</sub>SO<sub>4</sub>','FeSO<sub>4</sub> + H<sub>2</sub>S');" type="button" value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">  &nbsp;&nbsp;&nbsp; <input onclick="show(2,'Preparation of Hydrogen sulphide',1,1,1,1,0,0,'FeS + H<sub>2</sub>SO<sub>4</sub>','FeSO<sub>4</sub> + H<sub>2</sub>S');"   type="button" value="Show answer"></p>
+<p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer2">00:00</span>
+   <button type="button" onclick="startTimer('timer2')">Start</button>
+   <button type="button" onclick="stopTimer('timer2')">Stop</button>
+   <button type="button" onclick="resetTimer('timer2')">Reset Timer</button>
+ </p>
+  <p></p>
+  <h4>Reactions of Hydrogen Sulphide:</h4>
+  1. Hydrogen sulphide gas burns in limited amount of air to form  Sulphur and water:
+     
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q3a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q3b> O<sub>2</sub>&#8594; <input style="font-size: 16px; text-align: center;" size=1  name=q3c> S + <input style="font-size: 16px; text-align: center;" size=1  name=q3d> H<sub>2</sub>O </p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(3,'Reactions of Hydrogen sulphide',2,1,2,2,0,0,'H<sub>2</sub>S + O<sub>2</sub>','S + H<sub>2</sub>O');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(3,'Reactions of Hydrogen sulphide',2,1,2,2,0,0,'2H<sub>2</sub>S + O<sub>2</sub>','2S + 2H<sub>2</sub>O');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer3">00:00</span>
+  <button type="button" onclick="startTimer('timer3')">Start</button>
+  <button type="button" onclick="stopTimer('timer3')">Stop</button>
+  <button type="button" onclick="resetTimer('timer3')">Reset Timer</button>
+</p>
+  <p></p>
+
+ 2. In excess air Hydrogen sulphide gas burns with a blue flame to form  Sulphur dioxide and water:
+     
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q4a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q4b> O<sub>2</sub>&#8594; <input style="font-size: 16px; text-align: center;" size=1  name=q4c> SO<sub>2</sub> + <input style="font-size: 16px; text-align: center;" size=1  name=q4d> H<sub>2</sub>O </p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(4,'Reactions of Hydrogen sulphide',2,3,2,2,0,0,'H<sub>2</sub>S + O<sub>2</sub>','SO<sub>2</sub> + H<sub>2</sub>O');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(4,'Reactions of Hydrogen sulphide',2,3,2,2,0,0,'2H<sub>2</sub>S + 3 O<sub>2</sub>',' 2SO<sub>2</sub> + 2H<sub>2</sub>O');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer4">00:00</span>
+  <button type="button" onclick="startTimer('timer4')">Start</button>
+  <button type="button" onclick="stopTimer('timer4')">Stop</button>
+  <button type="button" onclick="resetTimer('timer4')">Reset Timer</button>
+</p>
+  <p></p>
+  3. Hydrogen sulphide gas reacts with Chlorine gas to form Sulphur and Hydrogen chloride gas:
+    
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center" 
+  size=1 name=q5a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q5b> Cl<sub>2</sub>&#8594;<input style="font-size: 16px; text-align: center;" size=1  name=q5c> S + <input style="font-size: 16px; text-align: center;" size=1  name=q5d> HCl</p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(5,'Reactions of Hydrogen sulphide',1,1,1,2,0,0,'H<sub>2</sub>S + Cl<sub>2</sub>','S + HCl');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(5,'Reactions of Hydrogen sulphide',1,1,1,2,0,0,'H<sub>2</sub>S + Cl<sub>2</sub>','S + 2H<sub>2</sub>O');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer5">00:00</span>
+  <button type="button" onclick="startTimer('timer5')">Start</button>
+  <button type="button" onclick="stopTimer('timer5')">Stop</button>
+  <button type="button" onclick="resetTimer('timer5')">Reset Timer</button>
+</p> 
+  <p></p>
+  4.Hydrogen sulphide gas reacts with Lead (II) nitrate solution to form black precipitate of Lead (II) sulphide:
+    
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q6a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q6b> Pb(NO<sub>3</sub>)<sub>2</sub>&#8594; <input style="font-size: 16px; text-align: center;" size=1  name=q6c> PbS + <input style="font-size: 16px; text-align: center;" size=1  name=q6d> HNO<sub>3</sub> </p>
+
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(6,'Reactions of Hydrogen sulphide',1,1,1,2,0,0,'H<sub>2</sub>S + Pb(NO<sub>3</sub>)<sub>2</sub>','PbS + HNO<sub>3</sub>');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(6,'Reactions of Hydrogen sulphide',1,1,1,2,0,0,'H<sub>2</sub>S + Pb(NO<sub>3</sub>)<sub>2</sub>','PbS + 2HNO<sub>3</sub>');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer6">00:00</span>
+  <button type="button" onclick="startTimer('timer6')">Start</button>
+  <button type="button" onclick="stopTimer('timer6')">Stop</button>
+  <button type="button" onclick="resetTimer('timer6')">Reset Timer</button>
+</p> 
+  <p></p>
+ 5.Hydrogen sulphide gas reacts with Copper (II) sulphate solution to form brownish black precipitate of Copper(II) sulphide:
+     
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q7a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q7b> CuSO<sub>4</sub>&#8594;<input style="font-size: 16px; text-align: center;" size=1  name=q7c> PbS + <input style="font-size: 16px; text-align: center;" size=1  name=q7d> H<sub>2</sub>SO<sub>4</sub> </p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(7,'Reactions of Hydrogen sulphide',1,1,1,1,0,0,'H<sub>2</sub>S + CuSO<sub>4</sub>','CuS + H<sub>2SO<sub>4</sub>');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(7,'Reactions of Hydrogen sulphide',1,1,1,1,0,0,'H<sub>2</sub>S + CuSO<sub>4</sub>','CuS + H<sub>2</sub>SO<sub>4</sub>');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer7">00:00</span>
+  <button type="button" onclick="startTimer('timer7')">Start</button>
+  <button type="button" onclick="stopTimer('timer7')">Stop</button>
+  <button type="button" onclick="resetTimer('timer7')">Reset Timer</button>
+</p> 
+  <p></p>
+ 6.Hydrogen sulphide gas reacts with Zinc sulphate solution to form white precipitate of Zinc sulphide:
+     
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q8a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q8b> ZnSO<sub>4</sub>&#8594;<input style="font-size: 16px; text-align: center" size=1  name=q8c> ZnS + <input style="font-size: 16px; text-align: center;" size=1  name=q8d> H<sub>2</sub>SO<sub>4</sub> </p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(8,'Reactions of Hydrogen sulphide',1,1,1,1,0,0,'H<sub>2</sub>S + ZnSO<sub>4</sub>','ZnS + H<sub>2SO<sub>4</sub>');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(8,'Reactions of Hydrogen sulphide',1,1,1,1,0,0,'H<sub>2</sub>S + ZnSO<sub>4</sub>','ZnS + H<sub>2</sub>SO<sub>4</sub>');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer8">00:00</span>
+  <button type="button" onclick="startTimer('timer8')">Start</button>
+  <button type="button" onclick="stopTimer('timer8')">Stop</button>
+  <button type="button" onclick="resetTimer('timer8')">Reset Timer</button>
+</p> 
+  <p></p>
+ 7.Hydrogen sulphide gas reduces Sulphur dioxide gas into Sulphur:
+  <p>   
+  <p style="font-size:115%; text-align:center;"> <input style="font-size: 16px; text-align: center;" 
+  size=1 name=q9a> H<sub>2</sub>S + <input  style="font-size: 16px; text-align: center;" size=1 name=q9b> SO<sub>2</sub>&#8594;<input style="font-size: 16px; text-align: center" size=1  name=q9c> S + <input style="font-size: 16px; text-align: center" size=1  name=q9d> H<sub>2</sub>O </p>
+ <p style="font-size:115%; text-align:center;"> <input onclick="check(9,'Reactions of Hydrogen sulphide',2,1,3,2,0,0,'H<sub>2</sub>S + SO<sub>2</sub>','S + H<sub>2</sub>O');" type="button"  value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset">&nbsp;&nbsp;&nbsp;&nbsp; <input onclick="show(9,'Reactions of Hydrogen sulphide',2,1,3,2,0,0,'2H<sub>2</sub>S + SO<sub>2</sub>','3S + 2H<sub>2</sub>O');" type="button" value="Show answer"> </p>
+ <p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer9">00:00</span>
+  <button type="button" onclick="startTimer('timer9')">Start</button>
+  <button type="button" onclick="stopTimer('timer9')">Stop</button>
+  <button type="button" onclick="resetTimer('timer9')">Reset Timer</button>
+</p>
+<p ></p>
+ 8.Hydrogen sulphide gas reduces Iron(III)chloride to Iron(II)chloride:
+<p style="font-size:115%; text-align:center;"><input style="font-size: 16px; text-align: center" 
+  size=1 name=q10a> FeCl<sub>3</sub> + <input style="font-size: 16px; text-align:center" size=1 name=q10b> H<sub>2</sub>S &#8594; <input style="font-size: 16px; text-align: center" size=1 name=q10c> FeCl<sub>2</sub> + <input style="font-size:16px;text-align:center" size=1 name=q10d> HCl + <input style="font-size:16px;text-align:center" size=1 name=q10e> S </p> 
+  <p style="font-size:115%; text-align:center;">
+<input onclick="check(10,'Reactions of Hydrogen sulphide',2,1,2,2,1,0,'FeCl<sub>3</sub> + H<sub>2</sub>S  ','FeCl<sub>2</sub> + HCl + S');" type="button" value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset"> &nbsp;&nbsp;&nbsp; <input onclick="show(10,'Reactions of Hydrogen sulphide',2,1,2,2,1,0,'2FeCl<sub>3</sub> + H<sub>2</sub>S  ','2FeCl<sub>2</sub> + 2HCl + S');" type="button" value="Show answer"></p>
+<p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer10">00:00</span>
+  <button type="button" onclick="startTimer('timer10')">Start</button>
+  <button type="button" onclick="stopTimer('timer10')">Stop</button>
+  <button type="button" onclick="resetTimer('timer10')">Reset Timer</button>
+</p> 
+<p ></p>
+
+ 9.Hydrogen sulphide gas reduces Nitric acid to reddish brown Nitrogen dioxide gas:
+
+<p style="font-size:115%; text-align:center;"><input style="font-size: 16px; text-align: center" 
+  size=1 name=q11a> HNO<sub>3</sub> + <input style="font-size: 16px; text-align:center" size=1 name=q11b> H<sub>2</sub>S &#8594; <input style="font-size: 16px; text-align: center" size=1 name=q11c> H<sub>2</sub>O + <input style="font-size:16px;text-align:center" size=1 name=q11d> NO<sub>2</sub> + <input style="font-size:16px;text-align:center" size=1 name=q11e> S </p> 
+  <p style="font-size:115%; text-align:center;">
+<input onclick="check(11,'Reactions of Hydrogen sulphide',2,1,2,2,1,0,'HNO<sub>3</sub> + H<sub>2</sub>S  ','H<sub>2</sub>O + NO<sub>2</sub> + S');" type="button" value="Check answer">&nbsp;&nbsp;&nbsp;&nbsp; <input type="reset" value="Reset"> &nbsp;&nbsp;&nbsp; <input onclick="show(11,'Reactions of Hydrogen sulphide',2,1,2,2,1,0,'2HNO<sub>3</sub> + H<sub>2</sub>S  ','2H<sub>2</sub>O + 2NO<sub>2</sub> + S');" type="button" value="Show answer"></p>
+<p style="font-size:115%; text-align:center;">
+  <span style="color:blue;"><b>Time Taken:</b></span><span class="timer" id="timer11">00:00</span>
+  <button type="button" onclick="startTimer('timer11')">Start</button>
+  <button type="button" onclick="stopTimer('timer11')">Stop</button>
+  <button type="button" onclick="resetTimer('timer11')">Reset Timer</button>
+</p>
+  
+ <p></p>
+
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