To find the formulae, you must add as many of the ions together to get a neutral charge. For example, one Li^+ ion and one NO2^- ion give LiNO2, which is lithium nitrite, but since CO3^2- has a charge of -2, it needs 2 Li^+ ions to make the neutral compound Li2CO3, lithium carbonate. Similarly, Cu^2+ needs 2 NO2^- ions to make the neutral compound Cu(NO2)2, copper(II) nitrite. To name these, simply add together the names of the ions used. Li^+ is lithium, Cu^2+ is copper(II), and Ba^2+ is barium. The negatively charged ions are named as nitrite for NO2^-, carbonate for CO3^2-, bisulfate for HSO4^- and phosphate for PO4^3-.
Answer: A catalyst is a substance that speeds up the rate of a chemical reaction without being used up and remains chemically unchanged itself .
Explanation: For a reaction to take place the particles must collide with enough energy for bonds to break and reaction to occur .
BUT when a catalyst is present the reactants are able to react in a way that requires less energy ,leading to more successful collision so the reaction speeds up without the chemical composition of the catalyst being affected
NOTE: the catalyst must be chosen to suit the particular reaction
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<u>Answer:</u> The relation between the forward and reverse reaction is 
<u>Explanation:</u>
For the given chemical equation:

The expression of equilibrium constant for above equation follows:
.......(1)
The reverse equation follows:

The expression of equilibrium constant for above equation follows:
.......(2)
Relation expression 1 and expression 2, we get:

Hence, the relation between the forward and reverse reaction is 
A circle graph, or a pie chart or graph, would be the type of graph that is best used when showing the <span>percentage of reactant molecules that collide during a reaction in a graphical representation. In addition, the circle graph mainly consists of a circle being divided into parts proportional to the whole.</span>