Answer is (4).<span>
<em>
</em></span>
<span><em>Explanation:</em>
</span><span>
<span>The given mixture contains an </span>insoluble solid<span> <span>and an </span></span>aqueous solution of salt.  <span>The insoluble solid is </span>sand. <span>
First </span><span>we have to separate </span>insoluble solid. <span>Sand can be separated by doing </span>filtration. When we filter the mixture sand can be seen as the residue on the filter paper. 
<span>After filtering the mixture, we should collect the </span>filtrate. <span>Filtrate is the </span>salt solution. <span>By doing </span>evaporation <span>we can get the </span>solid salt. <span>
First </span>and second choices are wrong <span>because </span>after evaporating water filtration
cannot be done and salt and sand will be mixed together.<span>
Salt cannot be
filtered out because the salt is soluble and it is <span>in
aqueous medium. Hence, third choice is wrong</span></span></span>
 
        
                    
             
        
        
        
Answer:
C 1:1
Explanation:
Hydrogen loses an electron to becone +1 which is a cation and flourine gains that electron to have a full outer shell on the 2p subshell to become -1 and is an anion so the ratio is 1:1.
 
        
             
        
        
        
evaporation. When a substance undergoes a change of matter from a solid to gas, it is the process of evaporation.
 Hope this helps
 
        
             
        
        
        
Answer:
How many grams of H2O are in 1.0 mole of H2O?
18.02 grams
The average mass of one H2O molecule is 18.02 amu. The number of atoms is an exact number, the number of mole is an exact number; they do not affect the number of significant figures. The average mass of one mole of H2O is 18.02 grams.
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