Answer:
1.95g of Mg(OH)2 are needed
Explanation:
Mg(OH)2 reacts with HCl as follows:
Mg(OH)2 + 2 HCl → MgCl2 + 2H2O
<em>Where 1 mole of Mg(OH)2 reacts with 2 moles of HCl</em>
To solve this question we must find the moles of acid. Then, with the chemical equation we can find the moles of Mg(OH)2 and its mass:
<em>Moles HCl:</em>
158mL = 0.158L * (0.106mol / L) = 0.01675 moles HCl
<em>Moles Mg(OH)2:</em>
0.01675 moles HCl * (2mol Mg(OH)2 / 1mol HCl) = 0.3350 moles Mg(OH)2
<em>Mass Mg(OH)2 -Molar mass: 58.3197g/mol-</em>
0.3350 moles Mg(OH)2 * (58.3197g / mol) =
<h3>1.95g of Mg(OH)2 are needed</h3>
 
        
             
        
        
        
Answer:
Questions 
Explanation:
The word "science" was obtained from the Latin word "Scire" which means "to know". Hence science is a systematic investigation into the nature of the universe.
Scientific investigations begin with asking questions about the universe. It is this curiosity to know about occurrences in the universe as well as how to solve problems in the universe that leads to fascinating scientific investigations and discoveries.
 
        
             
        
        
        
Answer:
. 
Explanation 
In HX , X is more electronegative than Y so HX will ionise more because of  ionic bond between H and X . On the other hand H₂Y will be less polar as compared to HX so it will ionise to a lesser extent . Hence Ka will be more for HX . Ka represents the degree of ionisation of acid . Higher the ionisation , higher is the value of Ka . H₂Y which is less polar will ionise less and hence it will have lesser value of Ka . 
Hence H₂Y will have value of 10⁻⁷ and HX will have value of ka equal to 10⁹ .