4.5 g of compound A (MW = 90) was used to make 250 mL of its aqueous solution. The
molarity of the solution in M is x $\times$ 10-1.
The value of x is _______. (Rounded off to the nearest integer)
Answer (integer)
2
Solution
Given, weight of compound A = 4.5 g<br/><br/>Molecular weight of compound A = 90 g/mol<br/><br/>Volume of solution (in mL) = 250 mL<br/><br/>Now, molarity is defined as number of moles of solute or compound A divided by volume of solution (in L).<br/><br/>$M = {{Number\,of\,moles\,of\,solute\,(n)} \over {Volume\,of\,solution}}$<br/><br/>$= {{{{4.5} \over {90}}} \over {{{250} \over {1000}}}} = 0.2$ = 2 $\times$ 10<sup>$-$1</sup> M<br/><br/>$\therefore$ $$n = {{Weight\,of\,solute\,(compound\,A)} \over {Molecular\,weight\,of\,solute\,(compound\,A)}}$$<br/><br/>Hence, x $\times$ 10<sup>$-$1</sup> $\mu$<br/><br/>x = 2
About this question
Subject: Chemistry · Chapter: Some Basic Concepts of Chemistry · Topic: Mole Concept
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