Chemistry Acetylene from calcium carbide is an endothermic or exothermic reaction

A large amount of heat is released, and the reaction is very violent: Cac2+2H2O, Ca(OH)2+C2H2

In the laboratory, calcium carbide is commonly used to react with water to produce acetylene. Because calcium carbide contains a small amount of calcium sulfide and phosphide, the acetylene produced is mixed with hydrogen sulfide, phosphine and other unpleasant odors. The water reaction is quite intense, and the amount of water added can be controlled by the separating funnel to adjust the outgassing rate.

Saturated salt water can also be used.

Principle: Calcium carbide undergoes a hydrolysis reaction to generate acetylene. Device: flask and separating funnel (no Qipu generator can be used). Cotton should be placed at the mouth of the flask to prevent foam from overflowing.

Reagents: calcium carbide (CAC2) and water.

Reaction equation: CAC2+2H oh Ca(OH)2+CH

Collection method: Drain gas collection method or downward drain gas collection method (not commonly used).

Exhaust Treatment: Ignition.

The preparation unit is similar to that of a gas such as hydrogen.

Formula: Calcium carbide brine acetylene is born, and copper sulfate is added in addition to impurities.

How about not using Qipuyi? Water absorption and heat release are vigorous.

Reaction formula: CAC2+2H2O=Ca(OH)2+C2H2

Explanation: 1Calcium carbide brine acetylene: "brine" refers to saturated salt water. The meaning of this sentence is that acetylene is produced by the reaction of calcium carbide and saturated salt water in the laboratory.

2.Impurities are passed into copper sulfate: "impurities" refers to the H2S and PH3 impurities mixed in acetylene, which means that in order to remove the H2S and PH3 impurities in acetylene, a purer acetylene can be obtained, which can make the gas pass through the copper sulfate solution.

3.How about not using Qipuyi? Water absorption and heat release are vigorous.

The meaning of this sentence is that the reaction between calcium carbide and water is also a reaction between solid and liquid, but why can't you use a Qipu generator? This is because on the one hand, the water absorption of calcium carbide is too strong, and the reaction between calcium carbide and water cannot be controlled by Qipu generator; On the other hand, the reaction is very intense, too much heat release, if you use the Qipu generator, there is a danger.

cac2+2h2o=ca(oh)2+c2h2+q

The reaction emits a lot of heat.

(1) Calcium carbide reacts with water to form acetylene and calcium hydroxide, and the equation of the reaction is: CAC2+2H2O ch CH+Ca(OH)2;

Therefore, the answer is: CAC2+2H2O CH CH+Ca(OH)2;

2) Propionaldehyde reacts with newly made copper hydroxide, and the aldehyde group is oxidized to a carboxyl group to generate propionic acid and cuprous oxide, and the equation of the reaction is: CH3CH2CHo+2Cu(OH)2