na2s (aq) + cd(no3)2(aq) → cds (s) + 2nano3(aq)  is which type of reaction?

synthesis

double-displacement

single-displacement

decomposition

double-displacement

Explanation:

Na2S (aq) + Cd(NO3)2(aq) → CdS (s) + 2NaNO3(aq) 

Let's look at the meaning f the various options before answering the question.

Single Displacement Reaction: A single-displacement reaction, is a chemical reaction in which one element replaces an/other element in a compound. It can be represented generically as: A + B-C → A-C + B

Double Displacement Reaction: A double-replacement reaction occurs when parts of two ionic compounds are exchanged, making two new compounds. A characteristic of a double-replacement equation is that there are two compounds as reactants and two different compounds as products. This is represented as AB + CD --> BC + AD

Decompostion Reaction: The chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction. This is represented as; A --> B + C

synthesis reaction or direct combination reaction is a type of chemical reaction in which two or more simple substances combine to form a more complex product. The reactants may be elements or compounds, while the product is always a compound. This is represented as; A + B --> C

Among all the reactions, the reaction fits the criteria of the double displacement reaction. Hence the correct option is double displacement.

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.