The main performance of cyanuric chloride
High flammability, reducing agent, lower liquid temperature than nitrogen
1. The flammability of cyanuric chloride:
The ignition temperature of pure hydrogen is 400°C.
The combustion of hydrogen in the air actually reacts with the oxygen in the air to produce water.
2H2+O2=Ignite=2H2O
A lot of heat is released during this reaction, and the flame is light blue (the glass tube in the laboratory does not see blue, but the yellow is the result of the presence of Na+ in the glass). The heat released during combustion is three times that of gasoline under the same conditions. Therefore, it can be used as high-energy fuel and used in rockets. my country's Long March 3 rocket uses liquid hydrogen fuel.
The impure H2 explodes when ignited. But there is a limit. When the volume of hydrogen contained in the air accounts for 4.0%-74.2% of the mixed volume, an explosion will occur when it is ignited. This volume fraction range is called the explosion limit.
Use a test tube to collect a test tube of hydrogen. Place the mouth of the tube close to the alcohol lamp. If you hear a slight "pop" sound, it indicates that the hydrogen is pure. If you hear a sharp popping sound, it indicates that the hydrogen is impure. At this time, it needs to be collected and inspected again.
If you use the exhaust method to collect, you need to block the test tube mouth with your thumb for a while to extinguish the flame in the test tube that may not have been extinguished, and then collect the hydrogen (or take another test tube for collection). After collection, use your thumb to block the mouth of the test tube and move it closer to the flame and then move it away to see if there is a "pop" sound until the test shows that the hydrogen is pure.
Hydrogen will emit a light blue flame when burned in the air. The device is to ignite directly in the glass tip tube, so can we really see the light blue flame?
In the glass, there are sodium ions, and the flame color of sodium ions is yellow. Therefore, with the above method, only yellow flames can be seen, but light blue flames cannot be seen. If you want to achieve a light blue flame, you can take the following methods:
Method 1: Use quartz catheter (high price, not suitable for ordinary middle school laboratories)
Method 2: Use a copper tube (it is deceptive, because the flame color of copper element is green, and copper can conduct heat, connecting the copper tube with a rubber tube will affect the air tightness when ignited)
Method 3: Since the yellow flame is caused by the sodium ions in the glass, we can use the flame color reaction to detect potassium by looking at the flame through the cobalt glass to eliminate the interference of sodium.
2. Cyanuric chloride reducibility
The reaction of hydrogen with copper oxide is essentially hydrogen reduction of copper elements in copper oxide, turning copper oxide into red metallic copper.
CuO+H2=heating=Cu+H2O
CO+3H2=High temperature catalysis=CH4+H2O
In this reaction, copper oxide loses oxygen and becomes copper, and copper oxide is reduced, that is, copper oxide undergoes a reduction reaction. The reducing agent has reducing properties.
According to the combustion properties of hydrogen, synthetic ammonia manufacturers can be used as fuel for aerospace, welding, military and other aspects; according to its reducibility, it can also be used to smelt certain metal materials.
In addition, the addition reaction of hydrogen and organic matter also reflects the reducibility of hydrogen, such as
CH2=CH2+H2→CH3CH3
1. Restore device
①The test tube mouth should be slightly inclined downward
②The tube for introducing hydrogen should extend into the bottom of the test tube
③The mouth of the test tube cannot be plugged tightly with a rubber stopper
④ Heating with an alcohol lamp outer flame
2. Experimental operation
①Pure hydrogen gas should be passed for a while before the experiment, and then heating should be started to prevent explosion
②After the experiment is over, remove the alcohol lamp first and continue to pass hydrogen until the test tube cools.
