It indicates the number of moles of reactants and products
Explanation:
The coefficients in front of the reactants and products in a chemical reaction represents the number of moles of reactants and products. 
Every reaction is made up of equal number of moles of reactants and products. Thus, chemical equations are written in such a way to obey the law of conservation of matter. 
The numbers used are usually whole numbers and the are very important in stoichiometry. 
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Number of moles brainly.com/question/1841136
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The reaction yields the product compound 2,4,5-tribromophenol.
<h3>Bromination of monohydroxy benzene</h3>
Bromination is an organic reaction in which aqueous bromine is made to react with another compound so as to introduce bromine into the molecule.
When we carry out the bromination of monohydroxy benzene, we obtain the compound 2,4,5-tribromophenol.
Learn more about benzene: brainly.com/question/14525517
 
        
             
        
        
        
a. 1,4332 g
b. 7.54~g
<h3>Further explanation</h3>
Given
Reaction
MgCl2 (s) + 2 AgNO3 (aq) → Mg(NO3)2 (aq) + 2 AgCl (s)
20 cm of 2.5 mol/dm^3 of MgCl2
20 cm of 2.5 g/dm^3 of MgCl2
Required
the mass of silver chloride - AgCl
Solution
a. mol MgCl2 :

From equation, mol AgCl = 2 x mol MgCl2=2 x 0.05=0.1
mass AgCl(MW=143,32 g/mol)= 0.1 x 143,32=1,4332 g
b. mol MgCl2 (MW=95.211 /mol):

From equation, mol AgCl = 2 x mol MgCl2=2 x 0.0263=0.0526
mass AgCl(MW=143,32 g/mol)= 0.0526 x 143,32=7.54~g
 
        
             
        
        
        
Answer:
convert 250.0 mL in Liters :250. 0 / 1000 = 0,25 LDensity = 1.240 g/LMass
Explanation: