/> we will
(05.01 mc)
what is the mass of 0.80 moles of mg? (1 point)
a.0 7.5 x 1023 grams
b.4.8 x 1023 grams
c.30 grams
d.19 grams

 The answer is:  [D]: " 19 grams " .

Explanation:

Given:  0.80 moles of Mg ;  

Convert to "g" (units of "g" ; that is "grams" of "Mg" ).

Using The Period Table of Elements, the molar mass of "Mg"  is:

       24.305 g / mol

0.80 mol * (24.305 g Mg / 1 mol Mg)  = ?  g  Mg  ?? ;

The units of "mol" cancel out;  since:  " mol/ mol = 1" ;  

and we have:  (0.80 * 24.305) g Mg ;

                        =  19.444 ;

                   →  Round this number to 2 (two) significant figures;  since there are 2 (two) significant figure in our given amount of Mg — " 0.80 mol" ;

                   →  19 g ;  which is our answer.

Hope this helps!

  Best wishes to you!